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Geology of the country around Faversham. Memoir for 1:50 000 geological sheet 273 (England and Wales)

By S. C. A. Holmes

Bibliographical reference: Holmes, S. C. A. 1981. Geology of the country around Faversham. Memoir Geological Survey Great Britain, Sheet 273, 117 pp.

• Author
• S. C. A. Holmes
• Contributors
• Stratigraphy G. Bisson
• Palaeontology R. V. Melville and Sir James Stubblefield
• Water supply M. Price
• Economic geology R. A. Ellison

Geological Survey of Great Britain England and Wales, Institute of Geological Sciences Natural Environment Research Council

London Her Majesty's Stationery Office 1981. © Crown copyright 1981. Printed in England for Her Majesty's Stationery Office by Ebenezer Baylis and Son Limited, The Trinity Press Worcester, and London. Dd 696478 C20. ISBN 0 11 884141 6.

• Author
• S. C. A. Holmes, MA formerly of the Institute of Geological Sciences, Exhibition Road, London SW7 2DE
• Contributors
• R. A. Ellison, BSc, R. V. Melville, MSc, Sir James Stubblefield, DSc, FRS and M. Price, MSc Institute of Geological Sciences, London
• G. Bisson, BSc Institute of Geological Sciences St Just, 30 Pennsylvania Road, Exeter EX4 6DT

(Front cover)

(Rear cover)

Preface

The Faversham district covered by the area of 1: 50 000 Sheet (273) is notable for a stretch of coastline of great geological, archaeological and historical interest, extending from the Isle of Sheppey to the Isle of Thanet. The combined effects of coastal erosion and landslipping have long presented serious problems. Inland the area supports rich pasture in the marshes, market gardening, etc. on the rising ground and afforestation on the high plateau of the Blean.

The original geological survey, on the one-inch scale, was published on Sheet 3 in 1868; it was made by W. Whitaker, T. McK. Hughes and W. B. Dawkins. Revisions to the Tertiary beds and additional Drift boundaries were added by C. E. Hawkins and published in 1872 and 1875.

The six-inch survey was carried out mainly by Mr S. C. A. Holmes and Dr S. Buchan, under the late Mr C. E. N. Bromehead and the late Mr F. H. Edmunds as District Geologists, between 1937 and 1946; in 1938 Dr J. R. Earp surveyed a tract eastward of Faversham. Advantage has been taken of more recent surveys by Mr J. G. O. Smart on the Canterbury (289) Sheet and by Mr P. E. Harding on the Ramsgate (274) Sheet to record additional data on Tertiary and Head deposits on the adjacent ground of Sheet 273.

Mr R. A. Ellison has added details of the sections in quarries active in 1976, and contributed to the chapter on economic geology. Opportunity has been taken to complete the present account for publication following the newly introduced reissue of New Series one-inch (1: 63 360) sheets on the scale of 1: 50 000.

There is an extensive literature on this classic area for the exposure of all the Tertiary strata from Thanet Beds to Bagshot Beds; the most valuable of the older detailed accounts is in the memoir by Whitaker, The Geology of the London Basin, published in 1872, while many later descriptions are to be found in the Proceedings of the Geologists' Association. Unpublished notes made by T. McKenny Hughes on Drift deposits were of particular interest during the progress of the new survey and have been incorporated in the present account, as were similar ones in the memoir on the Chatham (272) Sheet, first published in 1954. Whitaker, in The Water Supply of Kent, 1908, recorded well sections in detail, and the later coverage of well records is in the Geological Survey Wartime Pamphlet No. 10, Part V, by Dr S. Buchan and others, issued in 1940. In the Well Catalogue Series, records of wells in the area of Sheets 273 and 274 were published in 1964 in a catalogue prepared by Miss C. M. Cooling and others then of the Hydrogeological Department. The deep-seated geology of the area is known mainly from exploratory work for the Kent Coalfield; of existing publications on this subject the most generally useful for reference is the memoir on The concealed Mesozoic Rocks in Kent, 1923, but in the present memoir Mr G. Bisson has brought together for the first time the results of numerous researches and of coalfield exploratory work in recent years.

The district offered to Sir Joseph Prestwich exceptional opportunities for the study of the Tertiary beds in the many fine sections on the coast and inland, his conclusions being fully published in a series of now classic papers in the Quarterly Journal of the Geological Society. The London Clay cliffs of Sheppey and Herne Bay are an historic source of finely preserved fossils; in modern times the palaeontological studies of the late A. G. Davis and the late Arthur Wrigley, followed by those of Dr G. F. Elliot, on the London Clay fauna have been complemented by the systematic work of the late Mrs E. M. Reid and of Miss M. E. J. Chandler on its flora, published as a monograph and supplement by the British Museum (Natural History) in 1933 and 1961. In the early days of gravel exploitation in the Sturry area an unrivalled opportunity to obtain early Palaeolithic implements in situ presented itself to Dr Ince, a local resident. The late Mr H. Dewey, formerly Assistant Director at the Geological Survey, in collaboration with the late Reginald Smith of the British Museum, was instrumental in publishing geological results in 1925; these now have an added value seen in the light of the detailed mapping.

In recent years, sections in the Tertiary beds have continued to present much to the palaeontologist and stratigrapher and have occasioned visits by the Geologists' Association and detailed studies, notably by Mr H. J. Gamble and by members of the Tertiary Research Group.

In writing this memoir Mr S. C. A. Holmes has drawn on the field notes of Dr S. Buchan and Dr J. R. Earp and in its compilation has included accounts by Mr G. Bisson and Mr R. V. Melville respectively on the Concealed formations (Chapter 3) and the Palaeontology of the Tertiary formations (Chapter 7); Mr M. Price has contributed an account of the underground water supply of the district. In the preparation of Chapter 3 and the section on coal in Chapter 11, data and information from officers' reports supplied by the National Coal Board are gratefully acknowledged. We are indebted to the Keeper of Palaeontology of the British Museum (Natural History) for facilities in examining collections of Tertiary, Pleistocene and Holocene fossils, in which work, and also in studying the notebooks of the late A. S. Kennard, the services of the late Mr C. P. Castell were much appreciated. In assessing the effects of coastal erosion in recent years valuable information was obtained from the study of aerial photographs under the curation at that time of the Ministry of Housing and Local Government. Our thanks are also due to Mr J. N. Carreck and Dr M. P. Kerney for palaeontological records from the Head Brickearth deposits at Swalecliffe.

The palaeontology of the Palaeozoic formations has been dealt with by Sir James Stubblefield, who has contributed accounts of new faunal evidence from several of the early boreholes into Coal Measures, and by Dr M. A. Calver; further identifications were carried out by Dr W. H. C. Ramsbottom and on the Coal Measures flora by Dr R. Crookall. For the later formations fossil identification, except for Gault fossils from the Kent Coalfield examined by Dr R. Casey, was for the most part carried out by Mr R. V. Melville, with assistance from other specialists on the Pleistocene and Holocene non-marine mollusca and vertebrates. Changes in nomenclature and conclusions reached from the study of Carboniferous faunas on the adjoining Canterbury (289) and Ramsgate (274) sheets have been adopted to date.

An attempt has been made in this memoir to arrange the Head and River deposits so as to describe them in stratigraphical sequence. The field relationships of these drifts, established from detailed mapping, have been studied to this end in the light of the exceptional amount of evidence from non-marine mollusca and vertebrate fossils and from the distribution of human flint artifacts in this classic area of their provenance.

The memoir has been compiled and edited by Mr S. C. A. Holmes, initially while in office as District Geologist.

G. M. Brown, Director, Institute of Geological Sciences, Exhibition Road, South Kensington, London SW7 2DE. 11, November 1980

Six-inch maps

The following is a list of the six-inch (County Series) geological maps included in the area of Sheet 273, with the date of survey for each map. The surveying officers are S. Buchan, J. R. Earp and S. C. A. Holmes. Manuscript copies of the maps are deposited for public reference in the library of the Institute of Geological Sciences. They contain more detail than appears on the 1: 50 000 map.

Notes

• National Grid references are given in square brackets throughout. Figures with eastings between 9700 and 9999 relate to places in 100-km square TQ (or 51), those with eastings between 0000 and 2700 to places in 100-km square TR (or 61).
• Numbers preceded by the letter A refer to the Geological Survey Photograph Collection of the Institute.

Geology of the country around Faversham—summary

The Faversham district is notable for a stretch of coastline of great geological, archaeological and historic interest, extending along the southern side of the Thames Estuary from the Isle of Sheppey to the Isle of Thanet.

The rocks buried at great depth below the district are described from evidence obtained by deep drilling, and include the Carboniferous sequences that supported the past coal mining activities in the area. Most of the land surface is occupied by Tertiary rocks formed some 50 to 60 million years ago and these have long been a prolific hunting ground for fossil collectors. Such fossils as fruits of the palm and mangrove give clues to the past climates and environments of the area; all are considered in detail in this memoir.

The more recent deposits derived from the existing rivers and sea are also fully discussed with emphasis given to the river terrace gravels which have yielded remains of much importance in tracing the history of man. A section on the economic geology of the region is included and to complete the picture the effects of modern-day coast erosion and landslips are considered.

Geological sequence

(Geological succession)

The geological formations indicated by colour and symbol on geological map Sheet 273 are as follows:

The following concealed formations have been proved in borings:

Chapter 1 Introduction

Historical and general

As defined by New Series Sheet 273, the Faversham district, in the county of Kent, includes about a half of the Isle of Sheppey on the west and is bounded on the east by the Isle of Thanet. The coastal strip is of particular interest geologically and inland geological conditions exert a strong influence economically. All the northern half of the area is occupied by the shallow sea of the Thames Estuary.

To the names of the three mainland towns of Faversham, Whitstable and Herne Bay must be added the comparatively recently extended villages of Eastchurch and Leysdown in the Isle of Sheppey. Herne Bay grew only as a residential and seaside resort but the old-established towns of Whitstable and Faversham have been the centre of industries some of which, such as boat-building and fishery, have continued to this day.

Whitstable about 1830 is described by Samuel Lewis (1831, p.460) in the following words: 'On the shore by Tankerton are several copper-houses, where considerable quantities of copperas, or green vitriol, are manufactured. Whitstable Bay is frequented by a number of colliers, from which Canterbury and the surrounding places are supplied with coal, by means of the Canterbury and Whitstable railway…. Great quantities of Roman pottery have been found in dredging for oysters round a rock, now called the Pudding-pan, which is supposed by some to have been the island Caunos of Ptolemy, though now covered by the sea'. The Canterbury and Whitstable railway had been opened with great ceremony on 3rd May, 1830. At the southern end it passed through the first railway tunnel in the world, which was effectively driven mainly in the London Clay. Whether the source of the Roman materials off the coast is an old land settlement or merely foundered shipping, the amount of erosion there since Roman times has certainly been very great (see p. 102).

Tankerton is now a residential suburb of Whitstable. Informative accounts of the copperas works to which Lewis refers have been compiled by Goodsall (1957, pp. 142–159); they were part of the industry for producing green vitriol from pyrite, used for dyeing, tanning and the manufacture of ink and 'Spanish brown' for painters. In the sixteenth century pyrite was gathered for the making of brimstone; its later collection for copperas from the London Clay cliffs of Sheppey and elsewhere enabled 'fossilists' in the eighteenth century to obtain many fascinating plant and animal remains (only too easily to disintegrate owing to decay of the pyrite). The following from an account by Edward Jacob of Faversham (1777, p. 130) illustrates the nature of the copperas trade as well as the impressiveness of cliff erosion in Sheppey … being composed of Clay, and constantly washed at their Basis by the Tides which beat against them more especially when driven by strong Easterly Winds, they are continually wasting more or less, and falling down upon the Shore, where the Clay being by degrees washed away, the Fossils are left in great Abundance. So great is the Loss of the Land at the highest Parts, that sometimes near an Acre of it hath sunk down at once, though these Falls are indeed extraordinary. Minster, Shurland and Warden, are the three Manors to which these Cliffs appertain, the Proprietors whereof hire them out to different Owners of Copperas Works, who employ the neighbouring Poor to collect the Pyrites or Copperas Stone upon the Beach, at the Rate of about a Shilling per Bushel, which they deposit in Heaps, when collected, until a Quantity sufficient to load a Hoy is procured, when it is measured and paid for…. Many rare Specimens, both native and extraneous, far beyond any equal Space of Ground, perhaps the Universe can produce, are by these means preserved'. 'The Coperas Gatherers' sold their fossil finds to eager collectors and in the early nineteenth century the London Clay cliffs became also a source for the manufacture of cement from the septaria which were likewise gathered from the eroded debris (see, for instance, Shrubsole, 1887, p. 195) and from which fossils were similarly obtained.

Faversham, was formerly distinguished for its manufacture of gunpowder, established there in the sixteenth century and carried on into the present century in sufficiently isolated situations in the marshes, which also allowed for its comparatively safe movement by water. Possibly the first factory started work some time before 1558 and was the earliest in Britain (Percival, 1969, p. 1); certainly choice of sites arose from the availability of water-supply for power and floating transport determined by the late Quaternary creek topography of the area, and the nearby Tertiary sand belts provided abundant coppice wood for charcoal. Much of the ground dug out for brickmaking began to be worked at an early period in the town's history. Shipping in Faversham Creek continues but it is as an agricultural centre that the town now derives most of its trade, including the canning of fruit and brewing.

Agriculture and soils

John Speed (1611) says that the soil of Kent is 'in all places fruitfull, and in plenty equals any other of the Realme…. Only Mines (excepting Iron) are wanting: all things else delivered with a prodigall heart and liberall hand'. These remarks remain true for the Faversham district today, with the exception that ironstone (in this region developed locally in the Oldhaven Beds) is no longer of any importance. Fruit growing, hops and market gardening dominate the easily-worked soils of the sandy lower Tertiary formations and of the brickearths, near Faversham, and also there is a good deal of normal arable land; the latter type predominates in the valleys of the Great and Little Stour, especially near Preston, where the brickearth is exceptionally clayey and gives rise to a heavier soil; south and south-east of Herne Bay mixed farming, with some fruit and market gardening characterise both the outcrop of the more sandy Tertiary beds and also London Clay land wherever it is covered by brickearth or gravels; similarly a tract of brickearth northward of Blean has produced good arable land. Most of the cherry orchards can be used also as sheep-grazing. The rich alluvial marsh lands of Sheppey, Faversham, the Stour valleys and Chislet Marshes with the Wantsum valley afford excellent pastures; in contrast, the greater part of the London Clay tract known as the Blean (southward of Whitstable and Herne Bay) is an important afforested area that has been a dense woodland (mainly of oak) since the earliest historic time. Over some of this land it should be noted, however, that, apart from patches and pockets of gravel, a very thin sandy soil covers the clay, making it there better suited to conifers. In some parts of the Faversham area the London Clay has been farmed, but where it is bare of soil and poorly drained, as on much of Sheppey and adjoining Whitstable, it is very heavy to work as arable land and has mostly been kept under grass; on Sheppey it has provided additional sheep pasture and the highest beds, being somewhat more silty, are less intractable for growing crops; the same applies to areas where Claygate and Bagshot Beds or brickearth and gravel drifts occur. The thin chalk soils of the western part of the Isle of Thanet provide arable land of fair quality, especially where mantled by a little loamy Head.

The Faversham area forms a significant part of the region described by McRae and Burnham (1973) in an appraisal of the landscape of Kent; their review of soils, land use capability, agriculture and woodlands provides information primarily based on a study of soil profiles and associations. Of particular practical interest is the summarisation in their Chapter 5 of the capabilities for agriculture, horticulture and forestry characterising the different physiographic regions and controlled by the geology and soils. Following are some relevant items included by McRae and Burnham (1973); the page numbers quoted in the following paragraph refer to their account.

The Blean plateau carries much surface water gley which is noncalcareous; but variations are brought about by spreads of brickearth, gravel and loamy head as well as by a melange of gravel, sand and clay mixed with the underlying London Clay by cryoturbation (pp. 44, 49). The marshes of the Thamesside, Swale and Wantsum have ground-water gleys which change their character, such as calcareous content, according to local conditions of the Alluvium and the strata underneath or adjoining it (p. 48). An important part of the North Kent Fruit Belt is dependant on soils derived from Thanet Beds and brickearth, notably around Faversham (p. 83). In Sheppey and the Isle of Harty, heavy London Clay tracts are fringed with reclaimed marshland that, though also poorly drained, is specially renowned for its sheep, from which the name Sheppey is derived (p. 96). The London Clay soils of the Blean tend to improve near Whitstable (where brickearths occur) and allow some arable cropping near the coast (p.120). Where drainage schemes in the marshlands have been accompanied by successful lowering of the water table, as in Cleve and Nagden Marshes between Whitstable and Faversham, pasture has given way to arable land yielding wheat and potatoes (p. 101). Not all agricultural developments can be directly related to soil and subsoil conditions, however, and it is pointed out that the survival of extensive damp oakwood on an area of the suitable stagnogley soils of the Blean is in fact largely by historical accident.

Coal

The northern edge of the productive concealed Kent Coalfield is represented in the area by the now closed Chislet Colliery, near Westbere in the Great Stour Valley. Exploratory work thereat added considerably to our knowledge of the Upper Carboniferous rocks and their relationship to the overlying Jurassic and Cretaceous strata (see pp. 12–22).

Outline of geology

The general geology of the district (Figure 1) is more varied than appears at first sight from the preponderance of London Clay at the surface. The beds are gently folded and Alluvium and other extensive Drifts considerably modify the basic pattern of solid outcrops. Upper Chalk is the oldest formation seen at the surface; it is present southward and eastward of Faversham, where brickearth largely covers it, and also in the drift-free upland near Sarre that forms the western end of the Isle of Thanet; an inlier northward of Chislet is mostly covered by drift. Of the Tertiary beds below the London Clay, the Thanet Beds have the widest outcrop, around Faversham and north-east of the Blean; for although the Woolwich Beds and Oldhaven Beds cover a good deal of ground near Oare, Goodnestone, Hernhill, Herne and Hillborough they crop out only as narrow bands along the sides of the Great and Little Stour valleys and on the east of the Blean near Chislet. London Clay extends uninterruptedly across the whole of the central area from Hernhill and the Stour Valley to the coast; it also occupies the Isle of Sheppey, including the Isle of Harty, and forms hills in the marshes northward of Faversham and Graveney; small outliers cap hills near Oare, Graveney and Hernhill, while larger ones at Preston and Grove Hill are considerably masked by drift deposits. The highest points, near East-church in the Isle of Sheppey, carry small outcrops of Claygate Beds and Bagshot Beds.

The most widespread of the Drift deposits are Alluvium and Head Brickearth, the former in the marshes and river valleys and the latter on undulating ground, in valleys, on hill slopes and, locally, as at Blean, capping higher ground. The Head Gravel, frequently closely associated with the brickearths, is much more extensively developed than true River Gravels, the three terraces of which are confined to narrow stretches along the Stour Valley and have either now been mostly worked out or are covered by other drifts.

Denudation and river development

There are two main trends in the natural drainage of the area. One is approximately from south to north. West of the Blean small streams flow northward into the marshes bordering The Swale. The valley at Ospringe is dry a few kilometres southward of Faversham but after wet seasons the water level rises sufficiently to produce a stream which flows in Ospringe village street. At no time in the history of these watercourses were they strong enough to accomplish much erosion or to distribute the products as terraced gravels. The branching creeks near Faversham have been produced by marine drowning of an essentially 'dry-valley' topography, together with its characteristic drift deposits of Head Gravel and Head Brickearth; and though many of the island mounds, in the Graveney Marshes, for instance, are medieval<span data-type="footnote">Numbers of very small mounds in the marshes are modern in origin, having been built up from clods of earth consisting of alluvial clay, London Clay or, more rarely, sandy loam subsoil from the Thanet Beds, for example.</span> artificial structures (see p. 98), some large regular ones, such as Denly Hill (Plate 8), are relics of a dissected undulating clay tract where isolated hills of London Clay may have been worn down in their final stages by marine erosion, with land-slipping, as described by Hughes (in Whitaker, 1872, pp. 291–293). Some idea of the scale and rate of change in the relative levels of land and sea is indicated in a study of Romano-British and Medieval occupation sites on artificial mounds in Canvey Island that became buried beneath alluvium (Linder, 1940, p. 283). At this locality on the north side of the Thames Estuary the evidence suggests a rate of movement of about 0.2 m per century since Neolithic times. It is probable that some tectonic downwarping in the North Sea basin persisted into the Flandrian so that local drowning of the North Kent coast is a result of subsidence together with fluctuating sea level. The Swale channel itself and the marshes around the Isle of Harty appear to occupy valleys in the London Clay devoid of river deposits other than alluvial mud which is largely estuarine in origin. On the north side of the Isle of Sheppey small streams flowing northward are abruptly truncated at the deeply eroded cliff edge. In the Blean area similar northerly flowing streams are more fully preserved. They occupy valleys in the London Clay which are either bare of drift or contain deposits, usually brickearth, quite unrelated to the streams, which are incised into drift and solid alike. The most important of these watercourses reaches the sea at Swalecliffe.

The second, and generally older, line of drainage is from south-west to north-east, or from west to east, and is dominated by the ancient river valleys of the Great and Little Stour. The combined course of the Stour runs eastward beyond the district to the sea at Richborough; but near Chislet the valley receives from the west the water from another small stream system (Sarre Penn) which drains the London Clay from near Blean and is again incised into or cut through solid clay or Head Brickearth. A tiny stream drains into Chislet Marshes from the Lower London Tertiary beds near Ford. The channel of the River Wantsum is recent in origin and partly artificial, but a connection with the Stour probably carried tributary waters during Second Terrace times south-eastward across the region now occupied by Chislet Marshes. To judge from the presence of barnacles and indicators of brackish water in a fauna of mainly fresh-water type at Chislet and Grove Ferry it appears that sea water may have reached here to cause estuarine conditions temporarily at this early stage (p. 77). There is no evidence that deposits of a lower terrace or buried channel were ever laid down in this region, but much later, after a fall of sea level and after First Terrace deposits had accumulated in parts of the main Stour Valley, the sea again penetrated inland and during the Flandrian had invaded the whole area as far as West Stourmouth; an arm of the sea in fact continued to extend round the whole of the Isle of Thanet until Saxon times and both the Stour rivers drained into it at Stourmouth (Hardman and Stebbing, 1940, pp. 68, 80). The island mounds aligned mainly near the Stour and Wantsum courses are composed of Thanet Beds or of silty alluvial material derived from that formation and it is probable that many of them were artificially thrown up (see p. 96) during the last stages before the marshes were finally drained and the sea excluded. In recent years the aspect of the Great Stour valley near Westbere and Stodmarsh has altered as a result of man's activities in dredging gravel from underneath the Alluvium and in the flooding of the fresh-water marshes near Chislet Colliery. All the marshland areas were more or less affected by inundation during the great floods of 1953.

Study of the relationship of the Drift deposits of the Blean to those of the Stour Valley (see p. 62) has thrown light on the physiographical evolution of the area. A sequence of events included erosion and deposition by the River Stour and the small streams of Faversham and the Blean, but these were not the exclusive agencies suggested by the work of Coleman (1952, p. 63; 1954, p. 52) following indications by Wooldridge (in Smith, 1933, p. 166) and by Wooldridge and Kirkaldy (1936, p. 6). While it is recognised that, distributed downwards from the highest point of the Blean upland (in the Faversham area 109 m OD at Holly Hill), it is possible to distinguish many superficial erosional surfaces, some on Drift deposits and some on London Clay, it is thought, from evidence provided by the Head Brickearths and Gravels, that most of the erosion of the Blean was accomplished mainly by solifluction and melt-waters under periglacial conditions (cf. Coleman, 1952, p. 77), alternating with warmer periods. By contrast, the three classic terraces of Stour gravels, together with a buried channel, are confined to the present valley and a possible fourth terrace is closely aligned with it; in fact the river appears to have been established on approximately its present course at an early date. Near Chislet it received from the west and north-west tributaries which had been established prior to Second Terrace time. The main outfall, however, seems always to have been eastward to Richborough and Sandwich Bay.

Evidence of early man

The district has become famous on account of the many finds of Palaeolithic (and later) flint artifacts, especially those from the Stour river gravels near Sturry. (Dewey and others, 1925, p. 278; Dewey, 1926, p. 1429; Dewey and Smith, 1925, p. 117; see also British Museum guide, 1926, p.37 and Antiquaries Journal, 1929, p.244). Dr Ince, a local collector, successfully obtained many of them fresh from the gravel face while the Sturry pits were in work, each find being carefully localised in plan and section. Implements have been commonly found on the coast near Whitstable, Herne Bay and Reculver and also on high ground at some inland localities. In all these cases the implements derive from Head Gravel or Head Brickearth, but only very rarely have any specimens been obtained in situ. While some are evidently older than the Sturry cultures there are also representatives of younger stages. Prestwich (1861, p. 365; 1865, p. 254) drew attention to the significance of these finds but it was not until comparatively recent years, following on extensive collecting by local enthusiasts, that anything approaching a comprehensive view was obtained (Burchell, 1924, p. 203; Dewey and others, 1925, pp. 283, 284; Dewey, 1926, p. 1432; Dewey and Smith, 1925, p. 134; British Museum guide, 1926, p. 36). Of particular interest are sites at Swalecliffe (Worsfold, 1926, p. 334), Hoath (Bowes, 1928, p. 517) and, just south of the area, near Sturry, at Fordwich (Smith, 1933, p. 165).

It is necessary to express some reservation on the adequacy of implements as particular stratigraphical indicators. As long ago as 1930 when so much detailed collecting had already been achieved, a note of caution was sounded. A summary by Jessup (1930, pp. 14, 27, etc.) includes (p. 5) the remark that 'many implements that were at one time included in the Chelles stage are now thought to belong to the next stage of St Acheul…'. In this connection it is pertinent to recall comments by the late H. G. Dines (in Dines and Edmunds, 1929, p. 152) with regard to implements described by H. Bury from gravel terraces in the Farnham district. Mr Dines pointed out that 'if the current classification of implements is accepted as strictly chronological the question as to how different cultures came to be associated in the same terrace has still to be answered'. He added 'in view of the distribution in the gravel of the implements at Farnham the only conclusion that appears at all satisfactory is that the evolution of the successive types of implements was a prolonged process, and that the ranges of the styles overlap in the time scale'. Recent work has confirmed this suggestion. It is now known, for instance, that though the Acheulians elaborated (sometimes using hardwood baton or cylindrical bone tools) the 'traditional' Chellean type of artifact, no doubt according to the skill and intention of the maker, many of their implements were not taken beyond the 'Chellean Stage' in manufacture (cf. Oakley, 1972, p. 44). Dr Oakley explains that 'this term, like the better-defined Abbevillian, is being discontinued'; moreover, that all Acheulian industries include a proportion of roughly made hand axes, perhaps unfinished pieces or 'rough-outs' and that these have sometimes been identified rather misleadingly as of 'Chellean type'. The importance of geographical influences must also be taken into account. For example, the Mousterian industries of Neanderthal Man represent a culture which 'developed out of the Clactonian group, but was influenced by Acheulian and Levalloisian traditions' (Oakley, 1972, p. 56). 'Mousterian' was mistakenly used in older literature for industries which would now be classified as Clactonian or Levalloisian. The Clactonian industry is an example of a particular method or style of flint knapping which mainly produced only flakes. Further, the possibility of implements having been derived from deposits earlier than those in which they are found needs to be carefully considered in relation to the purely geological evidence; the range of cultures indicated by derived implements in a particular deposit may itself constitute important relative dating evidence.

Without thorough typological revision of the material it would hardly be possible to assess fully the independent evidence of human artifacts in dating the Pleistocene deposits of the Faversham district, either from published descriptions or from the extensive collections in the museums at Herne Bay, Canterbury and elsewhere. In the text reference is here made to finds from the more important localities; but the indications of probable culture stages should be regarded as provisional or as a descriptive label accepted by the authors quoted. Usage of the terms Abbevillian and Chellean has, for example, varied a good deal and where authors have applied either to the most primitive of the artifacts known in the Faversham district it seems, nevertheless, there may be little distinction between them and many early Acheulian forms. Fortunately recognition of some late Acheulian types has remained definitive. In the absence of a re-examination, the status of Clactonian within the area is at present uncertain. It is valuable to bring together the various lines of evidence from field records. Opinion in Quaternary researches has indeed tended in recent years to emphasise the role of the geologist in providing the basic framework of age and dating relationships for the archaeologist. Assistance in this is nowadays provided by a wealth of specialised techniques including radiometric dating, analysis of deep-sea cores and detailed pollen studies, all of which have helped in worldwide correlation problems (Oakley, 1969); no absolute-dating methods have so far been applied specifically to the Faversham district, but stratigraphical details provided by the six-inch survey have clarified a great deal, particularly where this has followed on original collection of artifacts that have been fully and carefully documented by location. Over a century ago the importance of thus relating flint implements to the drift deposits was already understood (Evans, 1860; Prestwich, 1860).

In a review of the Clactonian and Acheulian Palaeolithic industries in Britain, Wymer (1974, pp. 391–421) has drawn attention to further principles that are of significance for the geologist and are applicable to the Faversham district. Wymer (1974, pp. 393–394) points out that the accumulation of coarse gravel deposits must usually have been rapid relative to that of the alluvial silts, peats and marls that may be presumed to have formed during interglacial phases of the Pleistocene; in these circumstances it is only to be expected that implements would have been 'swept off surfaces or out of deposits belonging to a much earlier phase…' than that of the gravels, such as buried channel gravels, containing them. He adds 'however, the great concentration of flint artifacts in some river gravels, in fairly sharp condition, indicates that they are unlikely to have travelled far'. It is accepted (Wymer, 1974, pp. 411– 412) that there are some 'industries' or groups of artifacts that do suggest manufacture mainly controlled by inherited tradition, but it must be borne in mind that differences likewise can be the result simply of technical evolution or function. The Clactonian industry, for example, is a simple non-standardised one that also contrasts greatly with the hand-axe industries, but whether it could essentially represent an entirely different human group is open to question; it might be a 'facies' depending on local or immediate circumstances, and the impression of primitiveness that the Clactonian choppers, burins and scrapers may give should not imply that they were any the less efficiently functional. In dealing with the typology of hand-axe cultures (cordate-ovate; pointed) Wymer (1974, p. 416) cites an example of different traditions existing side by side and therefore not tenable as 'palaeontological markers' in their own right. He concludes (p. 417) that both Clactonian and Acheulian industries show preference for situations near water, that in the later part of the Hoxnian and in the Wolstonian differing hand-axe cultures existed together, but that Levalloisian industries may well generally indicate activities of people at a more recent time.

Current research is placing particular emphasis on quantitative analysis both of the tools present and of their particular characteristics, such as an assessment of the relative 'pointedness' or thickness of hand axes. It is becoming recognised that assemblages may reflect changes in seasonal activity or the availability and quality of raw materials. Hand-axes have been in use for at least 250 000 years and there has been a tendency for established types of tools to persist for a considerable time alongside newer types. Thus, rare Clactonian tools may even be found coeval with the Neolithic. Acheulian hand-axes have not been found in British pre-Hoxnian deposits. This was a very varied industry, in which the relative thicknesses of the implements tended to decrease in character with time; although elongate, pointed axes disappeared early during the last glaciation some small triangular shaped ones persisted. The 'Mousterian' flake tools that at one time were believed to post-date Acheulian hand-axes are now known first to occur as their contemporaries. The Devensian glacial stage saw the development of the blade industries that characterise the upper Palaeolithic. Mesolithic, Neolithic, Bronze Age and later human cultures mark the post-Glacial period.

Coast erosion and landslips

The London Clay cliffs of Sheppey, Whitstable and Tankerton, Hampton, Herne Bay and Beltinge offer exceptional opportunities for the study of landslips. The phenomenon is here closely connected with the erosion by the sea which has within a few thousand years extensively reduced the land on the south side of the Thames Estuary to the mud-banks which form the Kentish Flats. In Chapter 10 these kindred subjects are discussed in some detail. In the Reculver area the effect of marine erosion since Roman times may be deduced in a general way from a study of early documents and descriptions.

References

ANTIQUARIES JOURNAL. 1929. A palaeolith from Sturry. Vol. 9, No. 3, Notes, p. 244.

BOWES, A. 1928. Palaeoliths found in England. Antiq. J., Vol. 8, No. 4, Notes, pp. 517–518, pls. lxxx, lxxxi.

BRITISH MUSEUM. 1926. A guide to antiquities of the Stone Age. [3rd Edition, R. A. Smith.] (London: British Museum).

BURCHELL, J. P. T. 1924. The gravels at Reculver, Kent. Proc.Prehist. Soc. East Anglia, Vol. 4, Part 2, pp. 203–210.

COLEMAN, A. 1952. Some aspects of the development of the Lower Stour, Kent. Proc. Geol. Assoc., Vol. 63, pp. 63–86.

BURCHELL, J. P. T. 1954. The relief and drainage evolution of the Blean. Proc. Geol. Assoc., Vol. 65, pp. 52–63.

DEWEY, H. 1926. The river gravels of the south of England, their relationship to Palaeolithic Man and to the Glacial Period. C.R. 13e Congr. Int. Geol. 1922, pp. 1429–1446.

DEWEY, H. and SMITH, R. A. 1925. Flints from the Sturry gravels, Kent. Archaeol., Vol. 74, pp. 117–136.

DEWEY, H. WOOLDRIDGE, S. W., CORNES, H. W. and BROWN, E. E. S. 1925 The geology of the Canterbury district. Proc. Geol. Assoc., Vol. 36, pp. 257–284.

DINES, H. G. and EDMUNDS, F. H. 1929. The geology of the country around Aldershot and Guildford. Mem. Geol. Surv. G.B.

EVANS, J. 1860. On the occurrence of flint implements in undisturbed beds of gravel, sand and clay. Archaeol., Vol. 38, pp. 280–307.

GOODSALL, R. H. 1957. The Whitstable Copperas Industry. Archaeol. Cantiana, Vol. 70 [for 1956], pp. 142–159.

HARDMAN, F. W. and STEBBING, W. P. D. 1940. Stonar and the Wantsum Channel. Part I. Physiographical. Archaeol. Cantiana, Vol. 53, pp. 62–80.

JACOB, E. 1777. Plantae Favershamienses… with an appendix exhibiting a short view of the fossil bodies of the adjacent Island of Sheppey. (London.)

JESSUP, R. F. 1930. The Archaeology of Kent. (London.)

LEWIS, S. 1831. A Topographical Dictionary of England. Vol. 4. (London.)

LINDER, E. 1940. "Red-Hill" mounds of Canvey Island, in relation to subsidence in the Thames Estuary. Proc. Geol. Assoc., Vol. 51, pp. 283–290.

McRAE, S. G. and BURNHAM, C. P. 1973. The rural landscape of Kent. (Canterbury: Wye College (University of London) for British Association.) Canterbury.

OAKLEY, K. P. 1969. Frameworks for dating Fossil Man. Third Edition. (London.)

OAKLEY, K. P. 1972. Man the Tool-Maker. 6th Edition. (London: British Museum (Natural History).)

PERCIVAL, A. 1969. The Faversham gunpowder industry and its development. Faversham Papers, No. 4 (1967). 2nd Edition. (Faversham.)

PRESTWICH, J. 1860. On the occurrence of flint-implements associated with the remains of animals of extinct species in beds of a late geological period, in France at Amiens and Abbeville and in England at Hoxne. Philos. Trans. R. Soc. London, Vol. 150, Part 2, pp. 277–317.

PRESTWICH, J. 1861. Notes on some further discoveries of flint implements in beds of Post-Pliocene gravel and clay; with a few suggestions for search elsewhere. Q. J. Geol. Soc. London, Vol. 17, pp. 362–368.

PRESTWICH, J. 1865. Theoretical considerations on the conditions under which the (Drift) deposits containing the remains of extinct mammalia and flint implements were accumulated, and on their geological age; and on the Loess of the valleys of the South of England, and of the Somme and the Seine. Philos. Trans. R. Soc. London, Vol. 154, pp. 247–309.

SHRUBSOLE, W. H. 1887. Excursion to Sheppey. Proc. Geol. Assoc., Vol. 10, pp. 194–195.

SMITH, R. A. 1933. Implements from high-level gravel near Canterbury. Proc. Prehist. Soc. East Anglia, Vol. 7, Part 2, pp. 165–170.

SPEED, J. 1611. Theatre of the Empire of Great Britain. Book 1, Fol. 21–22. (London.)

WHITAKER, W. 1872. The geology of the London Basin. Mem. Geol. Surv. G.B.

WOOLDRIDGE, S. W. and KIRKALDY, J. F. 1936. River profiles and denudation–chronology in southern England. Geol. Mag., Vol. 73, pp. 1–16.

WORSFOLD, F. H. 1926. An examination of the contents of the Brickearths and Gravels of Tankerton Bay, Swalecliffe, Kent. Proc. Geol. Assoc., Vol. 37, pp. 326–339.

WYMER, J. J. 1974. Clactonian and Acheulian industries in Britain–their chronology and significance. Proc. Geol. Assoc., Vol. 85, pp. 391–421.

Chapter 2 Structural geology

The Faversham area lies on the northern side of the Wealden region of uplift, but, although there is a general northerly dip and the structure is broadly simple, it is diversified with lines of folding that are well shown by the disposition of the plane of Tertiary–Cretaceous junction, both at its outcrop and more especially as indicated at depth by numerous well-borings. The deep-seated structures in the Palaeozoic formations are separately treated in Chapter 3, dealing with the concealed formations. The Cretaceous strata rest unconformably on Palaeozoic, but there is evidence that a thin wedge of Jurassic rocks may be present between them in the extreme south (p. 20).

The lines of folding which have affected the Tertiary and Cretaceous formations may be conveniently discussed by reference to the diagram (Figure 2) showing the surface-contours of the Chalk beneath the Tertiary beds. The contours are drawn on the evidence of data obtained both from well and borehole records and from the relationship of these to the outcrops and to known thicknesses.

The junction of the Thanet Beds with the Chalk is transgressive on to higher horizons on the east only; elsewhere there is no expression of the pre-Tertiary folding movements which have been demonstrated in some parts of southern England.

The sequence of events from Cretaceous times, insofar as it has determined the dominant structures and stratal distribution in the present area, may be summarised as follows. On an ancient surface of Palaeozoic rocks, bounded on the south by a basin in which Jurassic and Wealden sediments had accumulated, the deposition of thin and irregular shoreline deposits of Lower Greensand was followed as the land surface subsided, by uniform Gault and a great thickness of Chalk. Towards the close of the Cretaceous period, however, a slow rise brought about a pause in sedimentation. Eventually, the basal Bullhead Bed of the Tertiary (Thanet Beds) was laid down unconformably on a slightly eroded surface of the Chalk, the beds of which had become gently tilted on the north-east. There followed another period of sedimentation, much more varied than in Chalk times, the record of which is preserved in the sequence from Thanet Beds to Bagshot Beds. Continued earth-movements were associated subsequently with elevation of the broadly anticlinal dome of which the Weald is the now denuded relic, and this rise produced the predominantly north-north-easterly dip of the Cretaceous and Tertiary formations within the present area. As the Wealden folding intensified, however, on a smaller scale the sheet of Cretaceous and Tertiary beds itself became folded, on lines of east-south-easterly trend, i.e. roughly parallel with that part of the Wealden uplift most nearly adjoining. Finally the beds were subjected to stresses which caused local gentle minor folding trending north-north-east, usually of quite limited extent. Subaerial denudation, the main agency in reducing the beds to the present configuration of the land, has to some extent been influenced by these various structures.

Dips to the north-north-east are sometimes measurable at the outcrop but are seldom more than the one or two degrees typical of the relatively gentle folding within the area. Of the two types of fold, parallel to the strike and to the dip, the former is more important and examples of it are described first.

The main anticlinal axis of the Isle of Thanet appears to die out beneath the marshes on its west side but is replaced westward by more complex structures. A narrow upfold persists past Reculver but soon disappears, and a relatively deep narrow syncline complementary to it extends west-north-west from near Marshside to the coast at Herne Bay. As seen on the foreshore in 1975, the slight upfolding appeared to govern a pattern of gentle curving outcrops exhibited by divisions of the Thanet and Woolwich Beds then prominantly distinguishable at low tide. It is this structure that is broadly responsible for the 'apparent monoclinal fold close by the promontory at the Oldhaven Reef' mentioned by Gamble (1968, p. 592). From Chislet Marshes through Ford and Herne another anticline is of major importance, for it affects the Chalk and Tertiary outcrops considerably. It persists west-north-west beyond Herne and there is evidence that a flattening of the north-north-easterly dip may extend as far as the area south of Swalecliffe, confirming a suggestion originally made by Whitaker (1872, p. 351) when he stated that this line of uprise 'extends further westward, judging from the depth of water in a well near Balls Street (south of Swale Cliffe) being only about 30 feet [9 m], which may be the thickness of the London Clay there'. The syncline to the south is also an important feature; it extends east-south-east from near Herne Common through Chislet Park and Grove and accounts for the presence of London Clay outliers near Preston. It continues beyond the sheet-boundary, where, as Whitaker (1872, p. 351) noted, it is eventually followed by the River Stour. South-west of Whitstable a trough appears to be developed north-westward through Seasalter. This structure may be reflected by the disposition of the Tertiary base where it is at depth in the north-east part of the Isle of Sheppey. The presence of Bagshot Beds near Eastchurch appears to be related to slight downfolding.

Folding parallel to the dip, the axes trending north-north-east, is of fairly frequent occurrence but less strongly and persistently developed. In the south-west corner of the sheet, west of Ospringe, where there is a weak fold, the 'obscure anticlinal axis of the Sindall Valley' mentioned by Hughes (in Whitaker, 1872, p. 350) enters the area. Faversham is situated on a broad syncline, bounded on the east by a fairly sharp anticline west of Goodnestone which does not persist as far as Graveney. The Tertiary formations between Goodnestone and Hernhill occupy a syncline. The main mass of the Blean country southward of Whitstable and Swalecliffe is a relatively undisturbed area of a very broadly anticlinal nature, but through Broadoak and west of Sturry a very gentle syncline extends south-west from the trough through Chislet Park to weaken and disappear, however, on entering the area of the Canterbury (289) Sheet. Eastward of Sturry gentle 'dip folding' occurs, of which the most noticeable features are synclines north of Stodmarsh and west of Preston, affecting the outcrop of the Tertiary beds beneath the Alluvium; but an anticlinal area probably occurs in the tract between Grove Ferry and West Stourmouth.

In the light of the evidence summarised above it is necessary to re-examine some of the conclusions expressed in earlier accounts. Whitaker (1872, p. 351) suggested that the Blean area of London Clay is bounded on three sides by inward-dipping beds; it appears, however, that the structures run mainly transverse to the borders of the Blean. Wooldridge (1923, pp. 177–178) describes folding in the Herne Bay–Canterbury district; but the anticline through Herne does not appear to be a direct prolongation of the Isle of Thanet fold and the Blean area is synclinal on northeast to south-west lines only locally near Broadoak and Sturry. Instead of forming a large outlier, the Tertiary beds of the mainland are continuous with those of the Isle of Sheppey and there is no evidence that the Swale channel cuts down to the beds below the London Clay. In later papers Wooldridge (1925, p. 273; in Dewey and others, 1926, pp. 185–186) refers again to the structural features of the area and postulates north to south monoclines bordering the Blean on its east and west sides; both the mapped outcrops and the borehole evidence now available appear to indicate, however, that the structures are mostly transverse to these lines.

In geomorphological accounts by Dr A. Coleman full use of geological detail from wells and boreholes and from mapped Tertiary outcrops was not attempted, so that the structural patterns deduced (Coleman, 1952, p. 74, fig. 4; 1954, p. 56, fig. 2) are necessarily inconclusive. A structure termed by Coleman (1952, p. 73) the Hernhill Anticline is based on an account by Collins and Gill (1923, p. 303) in which these authors sought to demonstrate east–west folding in the Tertiary beds at Hernhill and southwards. Neither of these interpretations can now be sustained. Cross-bedding in the Woolwich Beds explains the northerly dip of 5° which Collins and Gill refer to Whitaker (1872, p. 165), who, describing Oldhaven, Woolwich and Thanet Beds, in fact stated 'At the top the dip is 10° northward, lower down it is 5°, and at the junction with the Thanet Sand the beds are flat'. Moreover Whitaker was describing a road cutting, not the subsequently excavated pit [TR 064 606] 100 m SW of Hernhill Church; and he mentions also a 3° easterly dip nearby, in the lane a little north of the church. In following the outcrops hereabouts the formations dip gently and uniformly northwards and only the Oldhaven Beds show locally a somewhat irregular base, owing to their mode of deposition.

Probably the folding described affects broadly all the beds, Tertiary formations, Chalk and Gault, down to the Lower Greensand. Beneath the Cretaceous unconformity, however, the distribution and structure of the Palaeozoic rocks is but imperfectly known, and borehole data are confined to the eastern part of the sheet area. In the account of the concealed and deep-seated rocks (p.10) the results of recent work on deep boreholes are dealt with more fully.

Carboniferous rocks from near Chislet village southwards occupy a syncline which is the northern part of the basin of the Kent Coalfield. The axis of folding plunges approximately south-east, comparable with the east-south-easterly alignment that dominates the pattern of deposition of the concealed (lower) Mesozoic rocks in East Kent (see Lamplugh, Kitchin and Pringle, 1923, pp. 5,7,10). The same general direction persisted not only in Mesozoic times but also, as described above, continued late into the Tertiary period.

Dines (1933, p. 19) has discussed in some detail the structure of the Kent Coalfield. The extent and boundaries of the Palaeozoic formations were not clearly defined by the imperfect borehole data available, but in later deductions from these Baker (1935) has suggested that more than one main synclinal basin of Carboniferous and older Palaeozoic rocks may occur and postulated southerly overthrusting to account for certain interpretations of the records. An examination of the stratigraphical data (see p. 12) shows no reversal of succession, however, and knowledge concerning the apparent distribution of pre-Carboniferous rocks, which also provides little support for this view, has been amplified by further evidence from old and new boreholes, discussed in Chapter 3. SCAH

References

BAKER, H. A. 1935. An undiscovered Coalfield. The Iron and Coal Trades Rev., Vol. 131 (July–December), pp. 386–387,388, 466–467,516–519.

COLEMAN, A. 1952. Some aspects of the development of the Lower Stour, Kent. Proc. Geol. Assoc., Vol. 63, pp. 63–86.

COLEMAN, A. 1954. The relief and drainage evolution of the Blean. Proc. Geol. Assoc., Vol. 65, pp. 52–63.

COLLINS, I. and GILL, D. M. C. 1923. Notes on the geology of Boughton-under-Blean, with Report of Excursion. Proc. Geol. Assoc., Vol. 34, pp. 300–313.

DEWEY, H., WOOLDRIDGE, S. W., CORNES, H. W. and BROWN, E. E. S. 1925. The geology of the Canterbury District. Proc. Geol. Assoc., Vol. 36, pp. 257–284.

DINES, H. G. 1933. The Sequence and Structure of the Kent Coalfield. Summ. Prog. Geol. Surv. G.B. for 1932, Part 2, pp. 15–43.

GAMBLE, H. J. 1968. Field Meeting to East Kent. Proc. Geol. Assoc., Vol. 78 (for 1967), pp. 587–593.

LAMPLUGH, G. W., KITCHIN, F. L. and PRINGLE, J. 1923. The Concealed Mesozoic Rocks in Kent. Mem. Geol. Surv. G.B.

WHITAKER, W. 1872. The geology of the London Basin. Mem. Geol. Surv. G.B.

WOOLDRIDGE, S. W. 1923. The minor structures of the London Basin. Proc. Geol. Assoc., Vol. 34, pp. 175–193.

WOOLDRIDGE, S. W. 1926. The structural evolution of the London Basin. Proc. Geol. Assoc., Vol. 37, pp. 162–196.

Chapter 3 Concealed formations

Introduction

The south-eastern corner of the present area is underlain by Coal Measures which form the north-western part of the Kent Coalfield. Chislet Colliery (now closed) [TR 210 619] is situated at Hersden, some 3.5 km ENE of Sturry and 6.5 km SSE of Herne Bay, and its workings extended southwards on to the Canterbury (289) Sheet. Knowledge of the formations which underlie the Chalk within the map-area is largely confined to that which can be gleaned from the scanty known records of seven deep boreholes (Figure 3) which were sunk within this area during exploration of the coalfield from 1912 to 1914. These boreholes were followed by the sinking of Chislet Colliery shafts between 1914 and 1918. Since that time information concerning the Coal Measures, and to a lesser extent the overlying and underlying formations, had gradually accrued from the examination of tunnels and boreholes incidental to the exploitation of the coal (Figure 4).

In the country to the west of these explorations no deep borehole has been made within the area, and the nature of the concealed geological formations can only be tentatively inferred from the evidence of more distant boreholes at Bobbing and Sheerness East to the west on the Chatham (272) Sheet and at Chilham, Harmansole, Stodmarsh and elsewhere to the south on the Canterbury (289) Sheet.

Concealed formations which are either known or are reasonably assumed to be present are tabulated on p. x.

Palaeozoic formations

Rocks of Lower Palaeozoic age occur beneath Mesozoic strata in boreholes at Bobbing [TQ 874 651] at Chilham [TR 088 545] and possibly at Sheerness East [TQ 929 734]; it is therefore likely that this sequence also obtains beneath at least the south-western part of the area under description. Lamplugh and others (1923, pp.123, 154) described the Silurian (Upper Llandovery) strata at Chilham as 'Smooth graptolitic clay-slates, stained red and purple to a depth of 15–20 ft (4.6–6.1 m), banded dark blue and grey below' and the possibly Ludlow strata at Bobbing as 'Hard dull-grey micaceous sandy shale; slight purplish tinge in places; with a six-inch (0.15 m) band of quartzitic greywacke'. Stubblefield (in Dines and others, 1954, p. 12) confirmed the age of the rocks at Bobbing as Silurian, but suggested that they were probably earlier than Ludlow. However, from a study of the palynology of these rocks and a reassessment of the macrofauna, Lister and others (1969) conclude that the beds are of Caradoc age. At Sheerness East there is no faunal evidence of age.

At Herne [TR 152 644] and at Reculver [TR 227 690] boreholes the rocks beneath the Cretaceous deposits are probably of Devonian or Old Red Sandstone age, whereas at Herne Bay [TR 198 677] the evidence is insufficient to permit identification. The Hoades Court Borehole [TR 189 618] proved Coal Measures without bottoming them, while the boreholes at Rushbourne [TR 193 635], Chislet Park [TR 212 631] and possibly Chitty [TR 231 648] proved Coal Measures overlying rocks probably of Devonian age, with the probable intervention of some Lower Carboniferous strata. The Devonian rocks consist largely of mottled red and green sandstones with beds of conglomerate containing red and green pebbles; some mudstone is also present. On pp. 11–12 Sir James Stubblefield discusses certain borehole cores which were found at Chislet Colliery and which are believed to have originated from Chislet Park, Chitty and Rushbourne boreholes; they include rocks of Devonian and Lower Carboniferous age.

Carboniferous

In the account which follows the identifications of Carboniferous Limestone fossils are by Sir James Stubblefield and Dr W. H. C. Ramsbottom, those of Coal Measures marine fossils are by Sir James Stubblefield and Dr M. A. Calver, and those of Coal Measures flora and non-marine fauna are by Dr R. Crookall and Dr Calver.

Carboniferous Limestone

Carboniferous Limestone occurs in the south-east corner of the area. It is largely overlain by Coal Measures, which may overstep it to the north-west. Three underground boreholes at Chislet Colliery have been drilled to this formation. The first, Chislet No. 34 Borehole<span data-type="footnote">Originally known as Chislet No. 31 Borehole.</span> [TR 228 629], 2.1 km 062° from the Chislet Colliery North Shaft, reached Carboniferous Limestone at 489.69 m below OD (p. 12). Here the limestone was brownish grey, crystalline and oolitic, with occasional stylolitic markings and thin beds of striped silty mudstone. Fossils included the following: Garwoodia gregaria, Girvanella sp., Ortonella sp., calcispheres, Earlandia sp., Endothyra sp.,Koskinotextularia sp., Mediocris mediocris, Eostoffella sp., indeterminate juvenile rugose coral, cf. Actinoconchus planosulcatus, Composita cf. ambigua, Megachonetes cf. papilionaceus, Linoprotonia sp., Productus cf. garwoodi, cf. Quasiavonia aculeata and Reticularia?. This assemblage suggests a Holkerian (≡ S₂ Zone) age.

Carboniferous Limestone was reached at 638.86 m below OD in Chislet No. 35 Borehole [TR 218 597], which is on the Canterbury (289) Sheet (Smart and others, 1966, p. 20), and in Chislet No. 39 Borehole [TR 212 618] 275 m 125° from the North Shaft, the limestone was reached at 521.51 m below OD. Here cream oolitic limestone was associated with calcite mudstone, the formation being entered to a depth of 2.7 m. The fossils present included the following: algal nodules (including many examples of Garwoodia gregaria, Girvanella sp., Koninckopora inflata and Ortonella?, Earlandia sp., Endothyra spp., Koskinotextularia sp.,Pachythaerina sp., ?Quasiendothyra nibelis, tournayellid indet., 'Camarotoechia' sp., Linoprotonia sp., smooth spiriferoid and ostracods (including Paraparchites sp.). This assemblage is also of Holkerian age. GB

Faunal evidence for age of pre-Coal Measures sediments

In November 1944, the late Mr H. G. Dines and the writer collected samples from a miscellaneous series of core lengths dug from a path in the neighbourhood of Chislet Colliery with the kind co-operation of the colliery officials including Mr F. H. Price. The core lengths were stated to have been brought from Canterbury at the outbreak of the 1914 war and to have come from the boreholes made in the two preceding years at Chislet Park, Chitty, Hoades Court and Rushbourne. The purpose of the 1944 visit was to collect fossils to establish the age of the pre-Coal Measures strata penetrated and if possible to relate particular cores to specified boreholes. The diameters of a selection of the cores collected are recorded below with the results of their examination.

4-in (0.10 m) core

Conglomerate with hematite-coated pebbles in a red sandstone matrix [CS 1692]. Red crinoidal limestone pebble measuring 0.10 m by 0.05 m with Camarotoechia cf. nucula, Chonetes cf. striatellus, C. (Eodevonaria?) sp., Lingula cf. striata, Orbiculoidea cf. rugata, Whitfieldella canalis, Hormotoma cf. articulatum, Hyolithes forbesi, Tentaculites cf. tenuis, Aechima [Bythocypris] siliqua, Beyrichia cf. maccoyana, trilobite fragments [CS 1693–1708]: age of pebble probably Ludlow.

Another red crinoidal limestone pebble from similar conglomerate core with stick bryozoa and Hormotoma? [CS 1712–1713].

A third red crinoidal limestone pebble with gastropod fragments and punctate orthacean shell [CS 1714].

4½-in (0.11 m) core

Earthy grey crinoidal limestone with papilionaceous chonetid, orthotetid and productid brachiopod fragments [CS 1756–1761]: age, Lower Carboniferous.

Grey (white-weathering) calcite mudstone with algae, polyzoa and a Kirkbya-like ostracod [CS 1762–1765]: age, probably Lower Carboniferous.

Light grey crinoidal oolitic limestone with foraminifera [CS 1754–1755].

5½-in (0.14 m) cores

Oolitic limestone breccia with Hemitrypa sp. and Composita ? [CS 1716–1720]: age, probably Lower Carboniferous.

A 0.15-m length of richly fossiliferous grey-green calcareous shale (dip c. 10°) with bryozoa including Fistulipora sp., Rhabdomeson?, Athyris sp., Atrypa reticularis, A. cf. desquamata, Cyrtospirifer verneuili, gastropod indet., annelid jaw, Spirorbis sp.[CS 1721–1746]: age, Upper Devonian (Frasnian).

Black crinoidal limestone with Spiriferid and calcite veins [CS 1747]: age, Devonian or Lower Carboniferous.

Black crinoidal limestone with crinoid plates, tuberculate gastropod and fish debris [CS 1748–1750]: age, ?Devonian.

From the above-listed determinations it emerges that (a) several crinoidal limestone pebbles, probably of Ludlow age, occur in a red conglomerate in 4-in (0.10 m) cores and the age of the conglomerate is probably Downtonian or later Devonian; (b) Upper Devonian grey-green calcareous shale, richly fossiliferous and with a dip of 10°, occurs in 51-in (0.14 m) cores; (c) black crinoidal limestones occur with some calcite veins in 52-in (0.14 m) cores; (d) Lower Carboniferous grey crinoidal and oolitic limestones, and some calcite mudstones with algae are found in 41-in (0.11 m) cores.

Provenance of the fossiliferous cores collected

The conglomerate with probable Ludlow pebbles

Since none of the records claims that sediments of pre-Coal Measures age were encountered at the Hoades Court Borehole, the list of four boreholes is reduced by one. The only documentary evidence of core diameters available is derived from an incomplete suite of sheets of weekly returns of borer's progress relating to the Chislet Park Borehole, and kindly made available by the Chislet Colliery, Limited, in 1944. These sheets show that the borehole between the depths of 602.67 m and completion was bored with shot-crowns 5/-in (0.15 m) outside and 44-in (0.11 m) inside measurements. Thus, the 4-in (0.10 m) cores which apparently were bored by shot-crowns may have come from below 602.67 m at Chislet Park and there from 807.72 to 883.92 m red and green sandstones with conglomerates were logged by the bore master. Accordingly a conglomerate possibly of post-Ludlow age but containing probably Ludlow pebbles may occur at Chislet Park. Nevertheless, from Rushbourne Borehole red and green sandstones are recorded between 602.74 and 620.52 m and between 747.37 and 754.38 m; furthermore, a red and green conglomerate is noted between 754.38 and 759.13 m. The colour of the conglomerates is not stated in the log of the Chitty Borehole.

The Upper Devonian grey-green calcareous shale

From the foregoing paragraph it is unlikely that the Upper Devonian 5½-in (0.14 m) core came from Chislet Park Borehole unless it came from above 602.67 m.

The only log available which makes any reference to dip is that of Rushbourne Borehole where the 39.42 m unit of 'coarse (grey) sandstone' occurring between 620.52 and 659.94 m is said to have 'angle of beds 8 to 10°'. At higher levels in the same borehole appear two entries, 446.53 to 465.68 m 'hard shale containing lime', and from 521.31 to 540.36 m 'grey rag with shale partings'; in neither of these cases is dip mentioned. The Chitty Borehole log does not mention lime or limestone; even the words 'Carboniferous Limestone' are inserted alongside an entry 'bind'.

The black crinoidal limestone with calcite veins

'Basalt with quartz veins' is recorded at Rushbourne between 476.84 and 521.31 m and again between 573.02 and 575.33 m, the latter unit under the heading 'sandy shale with basalt'. Also at Chitty Borehole between 553.21 and 555.65 m 'basalt with quartz' was recorded. It is thought likely that in these records 'basalt' is a misnomer for black limestone, and 'quartz' for calcite. The cores collected were 5-i in (0.14 m) in diameter, a similar diameter to that of the Frasnian limestone; it is tempting though hazardous to suggest that both lithologies were found at Rushbourne.

The grey Carboniferous Limestone cores

These cores have lithological and faunal affinities with the Carboniferous Limestone cores seen in 1951 from an underground borehole at Chislet Colliery (p. 10), and may well be the 'white rock' recorded from 488.95 to 492.84 m at Chislet Park Borehole; the 'hard shale containing lime' at Rushbourne Borehole between 446.53 and 465.68 m may be represented by the 5Fin (0.14 m) core yielding Hemitrypa. The importance of these finds is:

1. That the 'northern limit of proved Carboniferous Limestone' as indicated by Dines (1933, pl. ii) can be extended north-westwards by at least 2.4 km in the neighbourhood of Chislet Park or Rushbourne. It can no longer be said positively that Carboniferous Limestone was absent at Rushbourne as stated by Dines (1933, p. 17).
2. That marine Upper Devonian deposits are proved in Kent for the first time.

From the admittedly circumstantial evidence at Reculver (p. 10), it is possible that marine Lower Devonian strata occur; from the presence of conglomerates at Rushbourne, Chitty and Chislet Park, it is likely that terrestrial Old Red Sandstone was also deposited in Kent, though apart from rhizodont fish and 'Estheria' at Harmansole [TR 142 529], faunal proof is as yet lacking (Lamplugh and others, 1923, p.121). CJS

Coal Measures

The Coal Measures (Westphalian) here, as elsewhere in Kent, rest directly on Carboniferous Limestone (Dinantian), except that they may overstep the latter formation to the north-west. Strata of Namurian (Millstone Grit) age have not been detected, but no angular discordance between the Carboniferous Limestone and the Coal Measures has been seen, although the age of the uppermost beds of the Carboniferous Limestone differs in various parts of Kent. The measures of the coalfield as a whole are folded into a major synclinal basin which plunges to the south-east. No evidence has been found of the stratal inversion inferred by Baker (1935, p. 466, fig. 2) to have taken place in the neighbourhood of Chislet Colliery, nor has up-boring from the colliery workings given support to Baker's view that Carboniferous Limestone overlay the Coal Measures at Chislet Colliery.

In the Chislet Colliery workings two main fault zones have been proved (Figure 4); that known as the Main East Fault is about 1780 m ENE of the Chislet Shafts, whereas the Main West Fault is approximately 290 m WSW of them. Faults in both zones are normal and strike about northwest to south-east, with downthrow to the south-west. The total vertical displacement of the Main East Fault is about 40 m, made up by four roughly parallel faults, of which three are of minor importance, but the Main West Fault is thought to consist of a single vertical displacement of 52 m. A third fault zone, known as the Stodmarsh Fault, is believed to strike almost parallel to the faults already mentioned, and to pass about 1370 m SW of the shafts; on the Canterbury (289) Sheet, where this fault was investigated by drilling, the throw was estimated to be between 75 m and 90 m down to the south-west (Smart and others, 1966, pp. 69–70). Between the major dislocations the Coal Measures are affected by numerous oblique lesser faults and by undulating folds.

The Coal Measures sediments tend to occur in rhythmic sequences or cyclothems, which ideally consist of mudstone with marine fossils overlain successively by mudstone with non-marine fossils, siltstone, sandstone, seatearth and coal; in practice the cycles are rarely perfectly developed, and any part of the rhythm may be missing. Dines (1933) divided the Kent Coal Measures into a Lower or Shale Division and an Upper or Sandstone Division. The Shale

Division is some 210 m in thickness and consists mainly of mudstones with coals, some of which are of workable thickness. The Sandstone Division is about 640 m thick and comprises mainly sandstones with a few mostly impersistent coal seams, except in its uppermost part, where shales again predominate. Dines later (1945) identified and correlated 14 more or less persistent coal seams in Kent, which he numbered Kent No. 1 to Kent No. 14 in downward order. The Coal Measures within the area of the present 1:50 000 map belong to the Shale Division, together with the lower strata of the Sandstone Division, and the seams represented are Kent No. 5 to Kent No. 14 of Dines' series.

Ten seams of coal were encountered in the course of sinking the Chislet Colliery shafts. These were numbered Chislet No. 1 to Chislet No. 10, starting with the uppermost. Subsequently a further seam below Chislet No. 10 was located by underground drilling, and was called Chislet No. 11 Seam. Dines (1945) considered that the Chislet No. 5 Seam was equivalent to his Kent No. 9 Seam, but this relationship was challenged by Stubblefield and Trueman (1946, p. 271), who suggested that the Chislet No. 5 Seam was more probably the correlative of the coal at 1022 m in the Tilmanstone Colliery Shaft, which had been referred to the Kent No. 7 Seam.

Stubblefield and Trueman (1946) described the faunal sequence in the Kent Coalfield. They named the marine beds then known to occur between the Kent No. 7 and Kent No. 6 seams the Tilmanstone Marine Beds, and they recorded the occurrence of the lower of these stratigraphically important beds at Chislet Colliery. They followed Jongmans (1940, p. 35) in suggesting that the Tilmanstone Marine Beds represented the Rimbert Marine Band of the coalfields of northern France, which in some places occurred as two bands, and they discussed the correlation of the beds in Britain, leaning towards the belief that they were equivalent to the Mansfield–Cefn Coed band of Yorkshire and South Wales. In addition Stubblefield and Trueman indicated the importance of the recording by Bolton (1915, pp. 664, 672) of Lingula at 902.00 m depth at Ripple Borehole, in the roof shales of the seam identified by Dines as Kent No. 12. Subsequently this horizon has been widely located in the Kent Coalfield and has been termed the Ripple Marine Band (Stubblefield, 1953, p. 42). It has been shown to be the local representative of the Amman Marine Band and the Clay Cross Marine Band of the South Wales and East Pennine coalfields, respectively by the discovery in it of Anthracoceratites vanderbeckei Ludwig sp. (Calver, 1956; Bisson and others, 1969, pp. 157–164).

The account of the Coal Measures which follows is largely based upon the correlation of the strata encountered in underground boreholes in Chislet Colliery (Figure 5) and (Figure 6). However, the available evidence is usually inadequate, particularly in the beds between the Chislet No. 11 and No. 5 seams, where splitting of the seams is common and thickness variations are great, so that the correlation is not wholly dependable and will doubtless require modification from time to time. In the wider sense, the identification of the Chislet Colliery coal seams with those recorded elsewhere in the Kent Coalfield is even more tentative, and the local Chislet seam numbers are therefore generally preferred to the Kent numeration of Dines (1945).

Lower Coal Measures (Westphalian A)

The basal stratum of the Coal Measures in this area is commonly a buff or light grey pyritous sandstone, with buff-coloured muddy streaks, sometimes with reworked and compacted Carboniferous Limestone at the base. This is overlain by conventional Coal Measures sediments in which Planolites ophthalmoides, Cochlichnus kochi and fish scales may occur.

The earliest known non-marine bivalves in the coalfield were found in the Chislet No. 35 Borehole where Carbonicola aff. bellula occurred 9.75 m above the Carboniferous Limestone surface; elsewhere in Britain similar shells have been found near the Millstone Grit–Coal Measures boundary. In the Chislet No. 34 Borehole, fish debris, including scales of Rhadinichthys sp. and Rhabdoderma sp. and a rhizodont tooth, occurred in a 1.5-m bed of very dark grey, almost black, thinly laminated mudstone in the roof of a thin coal which was some 12 m above the Carboniferous Limestone and was possibly the Kent No. 14 Seam. Near the middle of the bed the foraminifera Agathamminoides sp. and Ammodiscus sp. occurred. The latter was again found in the Chislet No. 39 Borehole, in a similar lithological environment, 0.6 m above a coal and 14 m above the Coal Measures base. In other British coalfields marine bands are known in the Anthraconaia lenisulcata Zone but are very rarely found in the Carbonicola communis Zone. At Chislet Colliery there is evidence of the latter zone 1.2 to 1.8 m above the foraminiferal horizon, and therefore, although it is possible that the black shaly mudstone under discussion belongs to the A. lenisulcata Zone, direct non-marine faunal evidence has yet to be found.

The foraminifera-bearing bed described above was overlain in Chislet No. 34 Borehole by grey silty mudstone containing small Curvirimula sp. intermediate between C. subovata and C. candela, Naiadites? and Geisina arcuata?. Above this occurred some 6 to 9 m of grey, highly micaceous sandstone and silty mudstone, which contained the following fauna: Curvirimula sp. nov.?, Carbonicola browni?, C. cf. cristagalli, C., C. polmontensis?, C. pseudorobusta?, Naiaditesfiexuosus, with Geisina arcuata. In Chislet No. 39 Borehole Spirorbis sp., Curvirimula cf. subovata, Carbonicola cf. communis, C. cf. cristagalli, Naiadites sp. and Geisina arcuata occurred at this horizon. These assemblages compared well with the C. communis Zone faunas collected by A. Temple-man from Chislet No. 28 [TR 219 624] and No. 29 [TR 203 615] boreholes, in which Carbonicola cf. bipennis and C. cf. martini were present in addition (Stubblefield and Trueman, 1946, p. 269). Immediately above in Chislet No. 34 Borehole there occurred a thin coal, and in its roof were found Geisina? and Curvirimula aff. subovata. These shells also indicated the C. communis Zone. They were associated with plants, including Alethopteris lonchitica, Asterophillites charaeformis, Calamites carinatus, Neuropteris obliqua and Sphenophyllum myriophyllum, while at the corresponding horizon in the Chislet No. 28 Borehole Calamites sp., Neuropteris heterophylla?, N. obliqua and the seeds Carpolithus and Samaropsis were present.

About 9 m above the uppermost Carbonicola, mentioned above, in the roof of a thin coal, examples of Anthraconaia sp. and Spirorbis sp. were found in Chislet No. 29 Borehole, while Naiadites? occurred above another coal some 3 m higher. The possibility that this fauna might indicate the Anthraconaia modiolaris Zone was mentioned by Stubblefield and Trueman (1946, p.270). Naiadites sp. was found 16 m above the uppermost Carbonicola in Chislet No. 39 Borehole, between two coals. At the equivalent horizon in Chislet No. 42 Borehole [TR 203 615] Naiadites sp. intermediate between N. productus and N. quadratus and 'Estheria' sp. were found, and in Chislet No. 41 Borehole [TR 212 620] N. sp. cf. productus occurred, beneath a coal which was taken to be the Kent No. 12 Seam. Plants were again present locally in the succeeding measures, including Annularia radiata, Lepidodendron sp., Mariopteris nervosa, Neuropteris gigantea and Sphenophyllum cuneifolium.

Middle Coal Measures (Westphalian B plus lower part of Westphalian C)

The base of the Middle Coal Measures is taken at the base of the Ripple Marine Band, following Stubblefield and Trotter (1957).

Ripple Marine Band

Approximately 52 m above the base of the Coal Measures in Chislet No. 34 Borehole there occurred marine strata consisting of about 2.7 m of micaceous fine-grained sandstone and coarse siltstone, with Lingula mytilloides, fragments of gastropods and nautiloids and fish remains including a scale of Rhabdoderma sp. Within 13 mm of the uppermost marine shell there was found the lowest shell of a non-marine fauna which included Anthracosia aquilina?, A. cf. ovum, A. cf. phrygiana, unusual elongated bivalves allied to Anthraconaia of the A. pruvosti–A. lanceolata group, and Carbonita sp., a collection which was the first from Kent to indicate an Upper Anthraconaia modiolaris Zone age (Bisson and others, 1967, p. 159). This marine band, occurring so closely beneath Anthracosia and about 30 m above shells of the Carbonicola communis Zone, confirmed the existence of marine strata in the A. modiolaris Zone in Kent, which was suggested by Stubblefield and Trueman (1946, p. 270).

The marine band has since been located in six other boreholes in Chislet Colliery (including the No. 35 Borehole on the Canterbury (289) Sheet), and it has been found to occur consistently between 70 and 80 m below the Chislet No. 5 Seam. Within the present area the known fauna comprises Lingula mytilloides, Orbiculoidea cf. nitida, Euphemites anthracinus, Retispira cf. undata, Aviculopecten gentilis?, Parallelodon cf. reticulatus, Polidevcia acuta, orthocone and coiled nautiloids, Cypridina?, Hollinella?, and Rhabdoderma sp. The richest faunal development was found in the Chislet No. 48 Borehole [TR 229 607]; elsewhere the fauna was limited, and it was confined to Lingula mytilloides in the Chislet No. 41 and No. 47 [TR 224 613] boreholes, but nowhere in this area was the band found to split in the manner seen in Betteshanger Colliery (Bisson and others, 1967, p. 159).

In Chislet No. 34 Borehole Spirorbis sp. and rather small Naiadites cf. productus occurred some 5 m higher than the uppermost A. modiolaris Zone fauna mentioned above, and such shells favoured inclusion in the Lower Anthracosia similis–Anthraconaia pulchra Zone, rather than the Upper A. modiolaris Zone. The overlying strata beneath the Chislet No. 11 (Kent No. 11) Seam yielded many plants in boreholes around the colliery shafts; for example, in the Chislet No. 28 Borehole the plants collected from the 23 m of beds below the Chislet No. 11 Seam included Alethopteris decurrens, Annularia radiata, Calamites suckowi, Cordaites borassifolius, C. principalis, Eremopteris artemisaefolia, Lepidophloios acerosus, Lepidophyllum sp.,Mariopteris daviesi?, M. muricata, M. nervosa, Neuropteris gigantea, N. heterophylla, N. obliquus, Renaultia rotundifolia, Sphenophyllum cuneffolium and Sphenopteris dilatata. However, in the area to the south and southeast coals seem to be developed in this part of the sequence. In Chislet No. 48 Borehole Naiadites quadratus was found in the roof of a coal which is some 5 m below that taken to be the Chislet No. 11 Seam, and in Chislet No. 46 Borehole [TR 240 628] Naiadites sp., Carbonita sp. and Palaeolimnadiopsii pruvosti Raymond pars occurred at the corresponding horizon.

The Chislet No. 11 Seam occurs at depths of from 33.83 to 57.00 m below Chislet No. 5 Seam, the separation in general increasing with distance south and east of the colliery shafts. The thickness of the seam varies from nought to 1.5 m, usually with one or more 'dirt' partings. The most consistently high thicknesses have been recorded south of the shafts. The roof measures of the seam have yielded, in drifts and boreholes, a fauna comprising Spirorbis sp., Anthraconaia cf. cymbula, A. cf. lanceolata, A. obscura, A. aff. pruvosti, A. cf. pulchella, Naiadites cf. productus?, Palaeolimnadiopsis pruvosti Raymond pars and Carbonita cf. scalpellus. A further fauna, comprising A. aff. cymbula, Anthracosia? and Naiadites sp., has been found about midway between the Chislet No. 11 and No. 10 seams in three boreholes (includ ing Chislet No. 35 Borehole). This evidence is considered to indicate that these beds are of basal Lower similis–pulchra Zone age, as suggested by Stubblefield and Trueman (1946, p.272).

The Chislet No. 10 (Kent No. 10) Seam varies in thickness from nought to 1.60 m, often with one or more 'dirt' partings, and it lies from 24.38 to 41.76 m below the Chislet No. 5 Seam. It is often closely overlain by seat-earth. In the sediments next above in the Chislet No. 28 Borehole fossil plants were found, including Cordaites borassifolius, lycopod megaspores, Neuropteris gigantea, N. heterophylla, Sigillaria sp. and Sphenophyllum cuneifolium. At about the corresponding horizon in Chislet No. 40 [TR 216 617] and No. 46 boreholes shells were found, comprising Anthaconaia cf. cymbula, Naiadites cf. productus and Carbonita humilis. In the Chislet No. 48 Borehole the Chislet No. 9 Seam is thought to be near the Chislet No. 10 Seam, and the fauna found above it is therefore not equivalent to that last mentioned; it consists of Spirorbis sp., cf. Anthracosia rubida, Anthraconaia or Anthracosia?, Naiadites sp.,Carbonita humilis and Rhizodopsis sp.[scales]. In other boreholes Naiadites?, Palaeolimnadiopsis pruvosti Raymond pars and Carbonita sp. have been found above the Chislet No. 9 Seam. The latter was 1.5 m thick on the north side of the Chislet Colliery North Shaft and 2.1 m thick on the south, with a 25-mm 'dirt' parting. In the South Shaft it consisted of 0.6 m of coal below, 0.33 m of 'dirt', and 0.3 m of coal above; according to borehole records it ranges up to 1.96 m, being generally thickest around the shafts and to the south, and it is usually a split seam. It occurs between 19.8 and 32.3 m below Chislet No. 5 Seam, and from 1.8 to 12..5 m above Chislet No. 10 Seam.

The Chislet No. 8 Seam occurs from 15.2 to 26.5 m below Chislet No. 5 Seam and from 1.5 to 12.5 m above Chislet No. 9 Seam. It varies in thickness from nought to 1.0 m (split), but is normally free from dirt partings. In its roof have been found Spirorbis sp. and Carbonita humilis, although commonly only plants occur in the beds between the Chislet No. 8 and No. 7 seams; those found in the Main West Drift were listed by Crookall (1933, pp. 47–49), comprising Alethopteris lonchitica?, Annularia cf. galioides, Asterophyllites grandis, Calamites schutzeriformis, C. suckowi, C. undulatus, Calamophloios sp., Carpolithus sp., Cordaites borassifolius, C. principalis, Dorycordaites palmaeformis, Eremopteris artemisaefolia, Lepidodendron cf. jaraczewski, Lepidophyllum sp., Lepidostrobus sp., Mariopteris sp., Neuropteris gigantea, N. heterophylla, N. obliqua, N. scheuchzeri, Pinnularia capillacea, Rhodea sp., Samaropsis sp., Sigillaria boblayi, S. tessellata, Sphenophyllum myriophyllum, S. saxifragaefolium, and Stigmaria ficoides. In addition Asterophyllites equisetiformis, Asterotheca miltoni and Neuropteris tenuifolia have been found in boreholes.

The Chislet No. 7 (Kent No. 8) Seam lies between 0.9 and 12.5 m above the Chislet No. 8 Seam and it occurs between 7.3 and 20.1 m below the Chislet No. 5 Seam, the separation generally increasing from west to east within the colliery area. In boreholes the thickness of the seam varied from nought to 1.45 m and there was a tendency for it to be greatest to the east and south of the shafts. Where the seam was formerly worked in the East District [TR 230 627] its thickness was found to range from 0.74 to 1.22 m.<span data-type="footnote">Information concerning the coal seams encountered in the colliery workings (Chislet No. 7, No. 5 and No. 4) is based upon the unpublished reports of officers of the National Coal Board.</span> It consisted of a 'Bottom Coal', up to 0.38 m of bright coal, overlain by a group of thin bands of dirty coal, 'dirt' and clay which ranged from nought to 0.46 m in thickness; above this the 'Second Top Coal' was composed of bright coal and varied generally from 0.15 to 0.25 m, but was locally absent, while the overlying 'Main Top Coal' was the most persistent subdivision of the seam, between 0.36 and 0.61 m thick, again consisting of bright or moderately bright coal. The whole was usually surmounted by a band of soft black 'dirt' up to 25 mm in thickness. The 'Main Top Coal' exhibited a well-developed cleat striking 018°.

Non-marine shells are commonly found at two horizons, respectively below and above a thin sandstone which usually occurs 3 to 6 m above the Chislet No. 7 Seam. The lower of these horizons has yielded the following fauna: Spirorbis sp., Anthraconaia cf. pruvosti, cf. Anthracosia rubida, Naiadites aff. obliquus, N. productus, 'Estheria' sp., Palaeolimnadiopsis pruvosti Raymond pars, Carbonita humilis, Rhadinichthys sp. Above the sandstone Spirorbis sp., Anthraconaia?, Naiadites cf. daviesi, N. aff. obliquus, N. aff. productus, 'Estheria'?, Carbonita humilis, C. cf. salteriana, and Rhabdoderma sp. have been recognised.

The Chislet No. 6 Seam has not been found to exceed 0.56 m in thickness; it occurs from 3.7 to 13.4 m above the Chislet No. 7 Seam, and from 1.2 to 8.2 m below the Chislet No. 5 Seam. Shells are rarely found above this seam, but in the Chislet No. 46 Borehole cf. Anthracosia rubida, poorly preserved Anthraconaia or Anthracosia?, Naiadites aff. productus, Carbonita humilis and a scale of Rhizodopsis sp. were collected, while Spirorbis sp. and Anthraconaia or Naiadites? occurred at this horizon in the Chislet No. 49 Borehole [TR 233 625]. The base of the Chislet No. 5 (or Kent No. 7) Seam was at 411.5 m below surface in the Chislet Colliery North Shaft, where the seam was 1.5 m thick. It is normally between 0.9 and 1.5 m in thickness, but it has been shown to vary from 2.1 to 0.3 m or less, and these variations have been attributed to slumping and to local removal and re-deposition of the upper part of the seam by the action of water. North-east of the shafts in the East District of the colliery, the seam is free from 'dirt' partings, but in the South-East District two thin 'dirt' bands occur some 0.51 and 0.30 m respectively below the top of the seam. The upper of these is the most persistent, but in the West District, south-south-east of the shafts, both partings have locally ranged up to 0.9 m in thickness. A characteristic thin band of cannel-like inferior coal is commonly present in the coal above the upper 'dirt' band; the 0.13-m of coal immediately below the lower 'dirt' band is generally dull in appearance and is distinctively cleated, while the 0.13-m next below consists of strong dull grey coal. Otherwise the seam is composed of bright coal.

At the shafts the Chislet No. 4 Seam is about 12 m above the No. 5 Seam, but this separation decreases eastwards and in the East District the two seams come close together. In this district the Chislet No. 4 Seam consists of moderately bright coal with some thin grey bands; it is divided into three beds of approximately equal thickness by two persistent clean partings. Two thin bands of coal commonly occur close beneath the main seam. Thicknesses up to 0.84 m have been recorded. Naiadites sp. has been found both below and above the Chislet No. 4 Seam in borehole cores, but the best fauna from above the seam was obtained at the site of the Chislet No. 43 Borehole [TR 237 631] where Naiadites obliquus, N. sp. nov. cf. productus and Carbonita humilis occurred. At this place about 2.4 m of beds separate the Chislet No. 5 and No. 4 seams.

In the Chislet shafts and in boreholes the Chislet No. 3 Seam has been shown to vary from nought to 0.9 m in thickness, and it usually has one and sometimes two "dirt" partings. It occurs from 3.4 to 13.7 m above the Chislet No. 4 Seam and from 9.4 to 18.6 m above the Chislet No. 5 Seam. Shells are uncommon above this seam, but in the Chislet No. 43 Borehole indeterminate bivalve fragments occurred with Carbonita cf. humilis. The following plants were collected from the beds between the Chislet No. 3 and No. 2 seams in Chislet No. 32 Borehole [TR 232 626]: Asterophyllites equisetiformis, Calamites suckowi, Lepidocarpon sp., Mariopteris sp., Neuropteris heterophylla and N. tenuifolia.

The Chislet No. 2 Seam is from 0.3 to 1.2 m thick, including one fairly persistent parting, and it is found from 1.8 to 9.4 m above the Chislet No. 3 Seam and from 18.0 to 21.6 m above the Chislet No. 5 Seam. Naiadites sp. was found in the roof measures of this seam in the Chislet No. 33 Borehole [TR 228 629], and Anthraconaia sp., Anthracosia sp. nov. cf. aquilinoides and Naiadites sp. occurred at the corresponding horizon in the Chislet No. 38 Borehole [TR 210 607]. The Chislet No. 1 Seam has been encountered from 4.0 to 8.8 m above the Chislet No. 2 Seam and from 22.3 to 27.1 m above the Chislet No. 5 Seam. The recorded thickness has varied from nought to 0.9 m, including 'dirt' partings, of which at least one is commonly present.

Snowdown Marine Band

In smooth grey mudstone above the Chislet No. 1 Seam in the Chislet No. 32 Borehole there occurred small ovoid bodies which were identified as Tomaculum?. At the same horizon in the No. 38 Borehole pellets and curved rod-like structures 0.4 mm in diameter, possibly of faecal origin, were found, together with a single specimen of cf. Geisina sp., while in the No. 43 Borehole Trigonoglossa? was closely overlain by cf. Tomaculum sp. Stubblefield and Trueman (1946, p. 278) recorded the presence of Trigonoglossa 83.2 m below the Millyard (Kent No. 6) Seam and 14.0 m below a 2.1 m thick marine band in a borehole at Snowdown Colliery, and indeed this lower marine band occurs widely but sporadically in the Kent Coalfield.

In the Chislet No. 23 Borehole [TR 207 605] Naiadites? and 'Estheria'? occurred immediately beneath the Lower Tilmanstone Marine Band, and in the No. 32 Borehole the plants Carpolithus sp., Lepidodendron ophiurus and Stigmaria ficoides were found in this position.

Lower Tilmanstone Marine Band

Stubblefield and Trueman (1946, p. 273) recorded the occurrence of this marine band in two underground boreholes and a cross-measure drift at Chislet Colliery, at distances varying from 40 to 43 m above the Chislet No. 5 Seam. The fauna included: Serpuloides sp., athyrid, Neochonetes granulifer, Tornquistia diminuta, Plicochonetes?, Crurithyris?, Lingula mytilloides, Lingula sp.[finely ornamented and with a median ridge in the shell], Orbiculoidea cf. nitida, Productus cf. carbonarius, Levipustula rimberti, Trigonoglossa cf. nebraskensis, Retispira cf. tenuis, Aviculopecten?, Palaeoneilo?, Parallelodon?, Polidevcia cf. attenuata, Hollinella cf. bassleri, cf. 'Cypridina phillipsi'. Since 1946 this marine band has been penetrated by five additional underground boreholes within Chislet Colliery, at heights ranging from 36.2 to 43.3 m above the Chislet No. 5 Seam; its thickness has been shown to vary from 0.9 to 3.7 m and the following have been added to the list of fossils known to occur within the present area: Serpuloides stubblefieldi, cf. Tomaculum sp., Donaldina sp.,Euphemites?, ?Platyconcha or Donaldina, Myalina?, Polidevcia cf. acuta, Yoldia?, and scales of Rhabdoderma sp. and Rhadinichthys sp. Lingula has been found up to 9 mm in length and Orbiculoidea up to 18 mm in diameter.

This marine band is correlated with the Cefn Coed Marine Band of South Wales and the Mansfield Marine Band of Yorkshire (Stubblefield and Trueman, 1946, p. 277; Bisson and others, 1967, pp. 163–164); it thus marks the junction between Westphalian B and C and the top of the Lower similis–pulchra Zone. This interpretation supports the suggestion of these authors that the upper part of the Upper similis–pulchra Zone and the lower part of the A. phillipsi Zone may be missing in Kent.

Upper Coal Measures

In view of the then uncertainty as to the age of the Tilmanstone Marine Beds Stubblefield and Trotter (1957, p. 3) took the base of the Upper Coal Measures in Kent at the base of the Sandstone Division, which, by Dines' definition (1933, p. 23), is at the bottom of the prominent sandstone which underlies the Kent No. 6 Seam. This horizon is commonly difficult to determine however.

In the Chislet No. 38 Borehole (Bisson and others, 1967, pp. 153–155) Naiadites sp. occurred about 13 m above the marine strata, possibly at the same horizon as cf. Anthraconauta phillipsii was found in an earlier hole, which was known as the Francois No. 4 Borehole [TR 207 617]. Naiadites? and Carbonita cf. humilis occurred 33.5 m above the marine band. Two seams of coal, respectively 0.33 and 0.46 m thick and 54.9 and 62.5 m above the marine strata, were thought to represent the split Kent No. 6 Seam, which is correlated with the Millyard Seam worked at Snowdown Colliery. In the roof of the lower of these seams there were found Spirorbis sp., cf. Anthraconauta phillipsii, cf. Anthracosia ovum, and Carbonita spp. The occurrence of Anthracosia above the Tilmanstone Marine Band is of unusual interest, because elsewhere in Britain this genus is unknown above the horizon of the Mansfield Marine Band. The Francois No. 4 Borehole penetrated some 40 m of strata above the Kent No. 6 Seam, and in these, non-marine bivalves were found at four horizons, the fauna including Anthraconaia cf. lanceolata and cf. Anthraconauta tenuis. It was concluded that these strata represented in part the zones of Anthraconauta phillipsii and Anthraconauta tenuis. A 0.3-m coal seam some 26 m above the Kent No. 6 Seam was taken to be the Kent No. 5 Seam; in its roof was found Anthraconauta?, and some 3 m higher there occurred the plants Calamites suckowi and Sphenophyllum sp.; Neuropteris heterophylla forma rarinervis was found at the latter horizon and some 6 m above.

Mesozoic formations

Jurassic

The known range of the concealed Jurassic formations in Kent is illustrated by Lamplugh and others (1923, p. 5, fig. 2). These formations strike about west-north-west to east-south-east, and dip south-south-west. They have been bevelled at the plane of unconformity which in this area separates the Jurassic from the Cretaceous strata, and which is accordingly underlain by successively older beds as it is traced from south-south-west to north-north-east.

Lias

No Lias was found in the Bobbing Borehole, but in the Chilham and Harmansole boreholes 6.7 and 5.5 m respectively of combined Middle and Lower Lias were recorded (Lamplugh and others, 1923, pp. 153, 123, 113). Lias may therefore occur thinly beneath the extreme southwestern corner of the present 1:50 000 sheet area; it has never been proved.

Great Oolite

In the Stodmarsh Borehole [TR 211 600], just south of this area, 13.1 m of strata of the Great Oolite occurred (Lamplugh and others, 1923, p. 175), while at Harmansole, Chilham and Bobbing thicknesses of 26.2, 40.8 and 22.6 m respectively were recorded (op. cit., pp. 113, 117, 123, 127, 153, 157). In addition Baker (1920, p. 788) recorded grey limestone between 320.0 and 332.0 m at Herne Borehole, which he believed to be of Bathonian age; this limestone was not mentioned by Lamplugh and others (1923 p. 182), however, and no Great Oolite was present at either Hoades or Rushbourne.

The record of the Chislet Colliery North Shaft showed 'Hard limestone' between 328.9 and 334.4 m, and a similar thickness of 'Limestone' and 'Hard limestone' combined was recorded between 331.6 and 337.1 m in the South Shaft, that is between 84.0 and 78.5 m above the base of the Chislet No. 5 Seam. It was formerly thought possible that this rock represented the Great Oolite or the Lower Cretaceous (p. 21). However, in 1958 two holes were made in the concrete lining of the South Shaft, respectively 85.3 and 81.6 m above the level of the No. 5 Seam landing (Bisson, 1959); it was difficult to reach and inspect the strata behind the lining, but grey Gault clay was obtained from the upper hole and hard grey sandstone approaching greywacke was present in the lower; this sandstone was almost free from calcite and showed general resemblance to the Coal Measures sandstones of the area. It is therefore now believed that the limestone is either thinner than recorded or that it is altogether absent from the section.

Forest Marble, Cornbrash, Kellaways Beds and Oxford Clay (and younger Jurassic strata)

No representative of the Forest Marble, Cornbrash, Kellaways Beds or Oxford Clay has been proved in any of the boreholes within the present area, but they are known to occur to the west and south, and it may be inferred that they probably extend under the south-west corner of the sheet-area.

Cretaceous

Wealden, Lower Greensand and Gault

Little evidence is available concerning the distribution of Wealden and Lower Greensand strata within the Faversham map-area. Burr (1913, pp. 733–734) stated that these formations were absent at Stodmarsh, but Lamplugh and others (1923, p. 175) allotted 17.1 in to them. At Harman-sole a combined thickness of 22.3 m of Folkestone and Sandgate Beds, Atherfield Clay and Wealden was recorded (op. cit., p. 112), while at Chilham 12.8 m of sandstones, sands and sandy clays were classified as Lower Cretaceous (op. cit., p. 122), Wealden deposits probably being absent. The Bobbing Borehole proved 11.0 m of Folkestone and Sandgate Beds combined, Atherfield Clay and Wealden being missing (op. cit., p. 153), while the Sheerness East Borehole apparently indicated 13.4 m of Lower Greensand, Wealden again being absent.

The Lower Greensand may be represented by thin deposits, for example of conglomeratic sandstones, in the eastern part of the area. The borehole records are imperfect, but there is some evidence that pre-Carboniferous Palaeozoic rocks may underlie the Cretaceous deposits in a tract of country extending westward from the Isle of Thanet towards Herne or beyond. These rocks may have formed a land-mass even during the Palaeozoic era, and littoral deposits may have been laid down around its fringe in Lower Greensand times. A conglomerate at the base of the Gault was seen to rest directly on Coal Measures in the Chislet Colliery workings 2760 m 054.5° from the North Shaft [TR 232 636]; it included large angular slabs of sandstone which lithologically resembled Folkestone Beds, implying that undisturbed Lower Greensand strata once occurred in the vicinity and were eroded by the Gault sea (Bisson, 1953). This conglomerate forms a natural base to the Gault and is grouped with it on stratigraphical grounds, but palaeontologically it is the time equivalent of the Douvilleiceras mammillatum Zone, which includes the uppermost division of the Folkestone Beds at East Cliff, Folkestone (Casey, 1961, p.535).

It may be concluded that Lower Greensand deposits underlie at least part of the west and south of the present area and that Wealden strata may occur in the south-east.

The Gault is everywhere present. Records of deep boreholes give few lithological details beyond describing it as 'Blue clay' or 'Blue shale'. However, from evidence in surrounding areas it may be inferred that the formation consists of dark blue or grey clays with occasional layers of phosphatic nodules and beds of glauconitic sand, especially near the base.

At Chislet Colliery North Shaft the Gault is 44.5 m thick. At Hoades, Rushbourne, Chislet Park, Reculver and Herne Bay boreholes its thickness has been recorded as 43.5, 49.3, 49.6, 48.2 and 47.2 m respectively, but the figures quoted for Hoades and Reculver may include some Lower Green- sand. At Chitty Borehole 39.6 m of Gault was said to occur, with the bottom at 263.7 m below OD, whereas approximately 1.2 km to the south, in Chislet Colliery workings the Palaeozoic–Mesozoic surface of unconformity was located at about 310 m below OD, and was seen to be gently undulating. This southerly fall is probably an expression of the post-Tertiary folding described on p. 8, for Chitty is situated on an anticline and the Chislet Colliery workings underlie the broad syncline of Tertiary and Cretaceous rocks which extends east-south-east across the Stour Valley. Records from other boreholes tend to show a similar correspondence of the Cretaceous base with that of the Tertiary. At Herne Bay, for instance, the base of the Gault, at 340.8 m below OD, is deeper than usual because of the west-north-west to east-south-east syncline thereabouts.

At Herne Borehole, Lamplugh and others (1923, p. 182) estimated the thickness of the Gault to be 80 m, but from their notes on samples seen and from calculations based on known thicknesses of Chalk and Gault, it is clear that the formation was not much more than 40 m thick. The larger estimate resulted from the difficulty in distinguishing chiselled fragments of Gault clay from the grey marl of the Lower Chalk. This point the above authors themselves emphasised in another connection, for farther south, at Chilham, a thickness of 68.35 m of Gault recorded by Dawkins (1913, p. 362) was considered excessive by Lamplugh and his co-authors (1923, p. 124), who estimated the probable thickness to be 55 m, approximately as at Harmansole (op. cit., p. 112). Westward, at Sheerness East, the thickness of the Gault has been interpreted as 48.2 m (op. cit., p. 183), but 40.8 m may be a more reasonable estimate (Dines and others, 1971, p. 24). At Bobbing the figure of about 54.3 m given by Lamplugh and others (1923, p. 153) conforms more closely to the general thickening towards the outcrop than does the figure of 43.9 m given by Dawkins (1913, p. 363).

In the boreholes at Hoades Court and Herne Bay 0.66 and 3.55 m respectively of conglomerate were recorded at the base of the Gault, and these occurrences were in accord with that seen in the underground workings north-east of Chislet Colliery shafts. At the place where the Coal Measures–Gault unconformity was first penetrated the section was as follows:

In the direction of advance of the coal-face, approximately north-east by north, the surface of unconformity rose 0.13 m in about 12 m; in the same distance the coal seam rose 2.29 m, and was soon cut out completely. Here the surface of unconformity was smooth and clearly defined, but in up-boreholes that were subsequently drilled to the unconformity it was found that where sandstone underlay the Gault basal conglomerate the uppermost 12 to 25 mm was often disturbed, showing partings impregnated with glauconite and containing comminuted shell-fragments and microfossils; the sandstone was also tinged with green for up to 0.25 m.

The 0.23 m conglomerate of the above section maintained its thickness in the Chislet No. 31 [TR 231 633] and No. 32 boreholes but it decreased to 0.10 m in the No. 43 Borehole and to 0.08 m in the No. 33 and No. 45 [TR 240 628] boreholes. It was examined petrographically by Mr R. W. Elliott, who separated the included fragments of rock into five groups as follows:

Group a

Fragments of light grey Coal Measures mud-stone occurring near the base, very close to their source.

Group b

Abundant slabs of light brown, medium-grained sandstone up to 0.15 m in length, only slightly worn, with sides sharply defined by joints and with ripple-marks on bedding planes. These rocks possibly represented a consolidated facies of the Folkestone Beds comparable with the Ightham or Oldbury Stone.

A thin section of a rock from this group showed abundant angular and subangular grains of quartz (diameters varying from 0.128 to 0.32 mm) and granulitised quartz, with some leucoxene, limonite and muscovite. Pale brown chlorite was common in interstitial areas. The heavy minerals included small grains of zircon, tourmaline and garnet. (E25281).

Group c

Cobbles from 0.05 to 0.08 m in diameter, many of which were composed of green or brownish green, hard, compact, fine-grained quartzitic sandstone, often well rounded on one or more sides, while remaining comparatively unworn on the others.

A thin section showed angular interlocking quartz fragments and some feldspar (albite, the grain-size commonly being 0.064 mm), chlorite, muscovite and a few flakes of biotite. Magnetite and limonite also occurred and the latter occasionally rimmed quartz grains. Zircon was noted. (E25280).

Other pebbles in this group consisted of fine-grained red-spotted light grey sandstone, milky quartz and phosphatised oolitic sandy limestone, possibly of Jurassic age. The latter contained frequent ooliths between 0.3 and 0.64 mm in diameter, which generally possessed a thin outer rim of limonite-stained chamosite and were commonly infilled by coarsely crystalline calcite. Fossil fragments included foraminifera generally replaced by phosphate and chamosite. Angular and subangular grains of quartz and feldspar (diameter often 0.19 mm) and pyrite were present, with a few small fibres of biotite. The groundmass consisted essentially of fine-grained turbid limonite-stained phosphate (E25283).

Group d

Well-worn and rounded pebbles, mostly less than 25 mm in diameter, of a variety of rock types including milky and smoky quartz, quartzite, green siltstone and a brown oolitic rock similar to that described as (E25283) above. Attached to this last pebble was a group of pyritohedral pyrite crystals. In addition a silicified acid igneous rock with sporadic large crystals of oligoclase and quartz in a fine-grained groundmass (E25286A) and a purple microporphyritic devitrified rhyolite with quartz and albite phenocrysts (E25599) were present.

Group e

Irregular fragments of concentrically laminated limonite-coloured silty phosphatic clay (E25284). Some of these fragments enveloped at least partially the matrix and smaller pebbles of the conglomerate, suggesting that the clay was formed at the same time as the conglomerate itself was deposited.

The matrix of the conglomerate was very variable in composition. One section was of dark grey sandy glauconitic clay composed essentially of clay minerals of low birefringence (possibly kaolinite and perhaps with some illite). Subangular and rounded grains of quartz were common (diameter often 0.19 mm). Rounded grains of bright green glauconite and paler green chlorite were also present. The groundmass was stained with limonite and rather turbid. Small granules of magnetite were present (E25284). Elsewhere pale grey concretionary phosphatic material predominated, enveloping pebbles, numerous grains of quartz and glauconite, and occasional sponge spicules.

The conglomerate yielded the following fossils, which have been named by Dr R. Casey: Gyrodes genti, Entolium orbiculare, Birostrina salomoni, Ludbrookia tenuicosta, cf. Resatrix (Dosiniopsella) vibrayeana, Beudanticeras newtoni, Douvilleiceras mammillatum, D. monile, Hamites praegibbosus, Protanisoceras sp. nov., Protohoplites (Hemisonneratia) aff. puzosianus, Otohoplites sp.[juv.] (group of O.raulinianus d'Orbigny sp.), tooth of Isurus mantelli. This fauna represents the Douvilleiceras mammillatum Zone, and the bed is thus the time-equivalent of the uppermost division of the Folkestone Beds at East Cliff, Folkestone, the Fourth Division of Price (1874, p. 139), and the overlying 'Sulphur Band' at the base of the Gault.

The Gault clay overlying the conglomerate contained dark brown phosphatic nodules which measured up to 0.05 m in diameter. At 0.46 m above the conglomerate a phosphatised fragment of Hoplites (Isohoplites) eodentatus occurred, indicating the eodentatus Subzone of the Hoplites dentatus Zone. From glauconitic dark grey clay 0.60 to 1.21 m above the conglomerate Dr Casey identified the following: Gyrodes cf. genii, Acila bivirgata, Birostrina concentrica, Beudanticeras sp., Hoplites baylei, H. cf. baylei, H. cf. dentatus, H. sp.(group of H. dentatus), H. cf. devisensis, H. aff. paronai, Lyelliceras lyelli, L. cf. pseudolyelli, Protanisoceras sp.(group of P. moreanum Buvignier). This ammonite assemblage indicates the Hoplites benettianus (=Lyelliceras lyelli) Subzone of the dentatus Zone. From 3.7 m above the conglomerate Dr Casey identified Hoplites cf. dentatus, which Owen (1971, p. 75) took to be indicative of the overlying Hoplites spathi Subzone. In addition to the above, the following fossils were not precisely localised: 'Aporrhais' sp., Leionucula ovata forma derancei, cf. Beudanticeras sanctaecrucis, Hoplites dentatus, H. sp. nov. and Neohibolites sp. GB

References

BAKER, H. A. 1920. Structural features of the East Kent Coalfield. The Iron and Coal Trades Rev., Vol. 101, pp. 785–788.

BAKER, H. A. 1935. An undiscovered coalfield. The Iron and Coal Trades Rev., Vol. 131, pp. 386–388,466–467,516–518.

BISSON, G. 1953. In Summ. Prog. Geol. Surv. for 1952, p.22.

BISSON, G. 1959. In Summ. Prog. Geol. Surv. for 1958, p.29.

BISSON, G. LAMB, R. K. and CALVER, M. A. 1967. Boreholes in the Kent Coalfield, 1948 to 1959. II. Palaeozoic rocks. Bull. Geol. Surv. G.B., No.26, pp.99–166.

BOLTON, H. 1915. The fauna and stratigraphy of the Kent Coalfield. Trans. Inst. Min. Eng., Vol. 49, pp. 643–702.

BURR, M. 1913. Ten deep borings in East Kent. Colliery Guardian, Vol. 106, No.2754, pp. 731–734.

CALVER, M. A. 1956. In Summ. Prog. Geol. Surv. for 1955, p. 53.

CASEY, R. 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, Vol. 3, pp. 487–621.

CROOKALL, R. 1933. Contributions to the geology of the Kent Coalfield. II. The fossil flora of the Kent Coalfield. Summ. Prog. Geol. Surv. for 1932, Part II, pp. 44–70.

DAWKINS, W. B. 1913. The South-Eastern Coalfield, the associated rocks, and the Buried Plateau. Trans. Inst. Min. Eng., Vol. 44, Part2, pp. 350–378

DINES, H. G. 1933. Contributions to the geology of the Kent Coalfield. I. The sequence and structure of the Kent Coalfield. Summ. Prog. Geol. Surv. for 1932, Part II, pp. 15–43.

DINES, H. G. 1945. Report of the Geological Survey. Pp. 7–25 in Kent Coalfield Regional Survey Report. (Ministry of Fuel and Power.)

DINES, H. G. HOLMES, S. C. A. and ROBBIE, J. A. 1971. Geology of the country around Chatham. Mem. Geol. Surv. G.B.

JONGMANS, W. J. 1940. Die Kohlenfelder von Gross Britannien, Kent Kohlenfeld. Meded. behoorende bij het Jaarsverlag over 1938 en 1939. Geol. Sticht. Geol. Bureau voor het Mijngebiet to Heerlen, pp. 15–36.

LAMPLUGH, G. W., KITCHIN, F. L. and PRINGLE, J. 1923 The. concealed Mesozoic rocks in Kent. Mem. Geol. Surv. G.B.

LISTER, T. R., Coms, L. R. M. and RUSHTON, A. W. A. 1969. The basement beds in the Bobbing Borehole, Kent. Geol. Mag., Vol. 106, pp. 601–603.

OWEN, H. G. 1971. Middle Albian stratigraphy in the Anglo-Paris Basin. Bull. Br. Mus. Nat. Hist. (Geol.) Supplement 8, pp. 1–164.

PRICE, F. G. H. 1874. On the Lower Greensand and Gault of Folkestone. Proc. Geol. Assoc., Vol. 4, pp. 135–150.

SMART, J. G. O., BISSON, G. and WORSSAM, B. C. 1966. Geology of the country around Canterbury and Folkestone. Mem. Geol. Surv. G.B.

STUBBLEFIELD, C. J. 1953. In Summ. Prog. Geol. Surv. for 1952, pp. 41–44.

STUBBLEFIELD, C. J. and TROTTER, F. M. 1957. Divisions of the Coal Measures on Geological Survey maps of England and Wales. Bull. Geol. Surv. G.B., No. 13, pp. 1–5.

STUBBLEFIELD, C. J. and TRUEMAN, A. E. 1946. The faunal sequence in the Kent Coalfield. Geol. Mag., Vol.83, pp.266–279.

Chapter 4 Chalk

Introduction

The Chalk of north-east Kent has been fully described by Osborne White in the memoir on the Geology of the country near Ramsgate and Dover (1928) wherein a summary of the earlier literature may be found. A resurvey of the Ramsgate (274) and Dover (290) sheets on the six-inch scale, however has enabled horizons in the Upper Chalk to be defined with greater stratigraphical precision, and a revised memoir is in course of preparation. In the present area there are no coast sections and the beds which appear at the surface are entirely Upper Chalk; but the full thickness of the formation is proved in boreholes which also afford some basis for the estimation of the thicknesses of the three divisions into which the formation may on lithological and palaeontological grounds be divided. The Lower Chalk is a little under 60 m thick and the Middle Chalk probably persists at about 60 m, but the Upper Chalk varies from 90 m upwards, due to the oncoming of higher beds eastward. The total thickness of the Chalk therefore varies from about 210 m, as in the Chatham area (Sheet 272), up to about 240 m calculated for the western Isle of Thanet where the highest horizons are present. Intermediate figures proved in coal exploration boreholes are, among others, 217.0 m at Thornden Wood, 219.8 m at Reculver, 224.6 m at Beltinge and at Chislet 224.9 m (North Shaft) and 226.0 m (South Shaft). The records are poor ones, however, and details of the beds are hardly recognisable; at the base of the Middle Chalk the Melbourn Rock appears to be present and the plenus Marls, at the top of the Lower Chalk, were identified at a depth of 226.2 m in a specimen from the North Shaft at Chislet Colliery.

Upper Chalk

The Upper Chalk is a uniform white limestone, mostly friable and soft, but diversified with occasional hard beds varying from 0.05 m to a metre or so in thickness and with flints mostly in fairly regular bands. Subdivision by lithology alone is difficult; but evolutional changes in the echinoid genus Micraster, together with the distribution of the plates of the free-swimming crinoids Uintacrinus and, outside the present area, Marsupites constitute the main basis for the recognition of the zonal divisions.

White (1928, p. 20) has summarised the lithological and faunal characteristics of the zones of the Upper Chalk in East Kent, based largely on the classic work of A. W. Rowe on the coast sections. The zones concerned in the present area are as follows:

• Uintacrinus socialis Zone
• Micraster coranguinum Zone
• Micraster cortestudinarium Zone
• Holaster planus Zone

Present-day usage assigns zonal status to the chalk with Uintacrinus, though the beds have been commonly referred to as a band or subzone within the next higher Marsupites Zone. The term UintacrinusBand' was generally accepted when it was decided to represent its limited area of outcrop on Sheet 273 by the symbol U.B., with the base of the zone indicated by a line mapped on the 6-inch scale, from palaeontological evidence. In defining this line inland the 'Barrois' sponge-bed' of the north coast of Thanet (White, 1928, p. 24; Rowe, 1900, pp. 295, 296, 299) which has been identified at Monkton, on Sheet 274 about 1.5 km eastward of the sheet boundary, could not be traced into the area of Sheet 273, for there are few large exposures to indicate this or any similar lithological datum line and the sponge bed also probably becomes indefinite. The lowest occurrence of the distinctive irregular polygonal plates of Uintacrinus was used, therefore, as the essential criterion. As Rowe points out, the plates become rarer near the base of the zone and isolated arm-ossicles are not to be relied upon as indices of horizon. Above the 'Barrois' sponge-bed in the Thanet coast sections Uintacrinus socialis is entirely absent for several metres and does not occur commonly until the horizon of another, weaker, sponge bed about 4.6 m higher up is reached. In showing an approximate line separating the two zones use has been made of records both of the more richly fossiliferous beds higher in the zone and of the top beds of the M. coranguinum Zone, with abundant Conulus, a little below. Hawkins (1918, p. 199) proposed for Hampshire a 9 to 12-m 'Sub-zone of Conulus albogalerus'. Though such a subdivision has proved too imprecise for definition and general usage, it is notable that in the present district the top 30 m of chalk of the coranguinum Zone frequently contains this echinoid, which is abundant in the top 15 m. It commonly occurs concentrated in bands a few centimetres thick, one of which lies just above the Barrois' sponge-bed in the Thanet coast sections and is there a useful marker at the base of the Uintacrinus socialis Zone.

Throughout the coranguinum Zone the best index of stratigraphical position is afforded by the evolutional stages of the zone fossil. A useful summary by the late Mr C. P. Chatwin of these progressive changes of features, together with notes of variant forms of Echinocorys scutata in this and the succeeding zone, may be found in the memoir on the Dartford district (Dewey, Bromehead and others, 1924, pp. 18–25).

Chalk of both the above zones can be studied from exposures in the Faversham area, but regarding the zones below little definite information is available from boreholes. A well-boring [TR 001 602] 165 m SSE of the church at Ospringe terminated in hard rock-chalk at 60.1 m which is probably at the base of the Holaster planus Zone. Another hard rocky bed, 1 m thick, about 18 m above this, probably marks the junction of this zone with the cortestudinarium Zone. Calculation from this record and from the evidence of horizon afforded by the nearby section in chalk of the coranguinum Zone (see below) provides an estimate of the thickness of the latter zone and gives a total of 90 m of Upper Chalk calculated to the base of the Thanet Beds. The amount of Upper Chalk present and the zonal thicknesses are here comparable with those in the Chatham district (Sheet 272) viz: H. planus Zone 18 m, M. cortestudinarium Zone 24 m, M. coranguinum Zone 49 m present. Eastward the Upper Chalk thickens (probably reaching a maximum of about 115 m in the present area) owing to the oncoming, beneath the overstepping Thanet Beds, of the highest beds of the coranguinum Zone and eventually of chalk of the succeeding Uintacrinus socialis Zone. The coranguinum Zone reaches a total of about 60 m, and about 12 m of Uintacrinus Zone chalk is present at the western end of the Isle of Thanet. In the eastern half of the map-area excluding the Isle of Thanet an Upper Chalk thickness of about 104 m, with no Uintacrinus beds, is probably general.

Apart from the fossil content there is little variation in the character of the chalk exposed in the area. Flint bands tend to diminish in frequency and prominence towards the top but scattered flints are present. In the Uintacrinus Zone the chalk tends to be somewhat lumpy and brownish stained at some levels. SCAH

Details

Micraster coranguinum Zone

Chalk of this zone is exposed in the Faversham district and in a tract north of Sarre in the Isle of Thanet.

At the southern border of the Sheet, 0.8 km SW of Syndale Bottom three small pits [TQ 981 603] on the north-west side of the road showed clean white, practically unfossiliferous chalk with flint bands. Chalk, largely drift-covered, appears, partly as an inlier, in the valleys south-west of Luddenham, and a pit [TQ 982 621] at Stone Farm exposed beneath 1.8 m of Thanet Beds some 8 m of soft blocky chalk with Echinocorys scutata, Conulus albogalerus, and Praelacazella [Thecidea]wetherelli; there are bands of nodular flint and a prominent tabular band about 1.8 m from the top.

The large pit [TR 003 603] about 320 m E of the church at Ospringe exposed 18 m of chalk, firm and blocky, with flint bands averaging 0.6 to 1.2 m apart. Beneath a fairly prominent marly bed the bottom 6 m of chalk is fossiliferous and yielded Micraster coranguinum, M. coranguinum var. latior, Echinocorys scutata, Conulus albogalerus and Praelacazella wetherelli. The horizon is about 30 m down in the zone.

On the south-east side of Faversham three pits in the Preston neighbourhood and one south of Ewell have yielded coranguinum Zone fossils without any indication of higher beds beneath the Tertiary formations. The pit [TR 022 609] 0.5 km E of the Station and adjacent to an old brickyard exposed 3.4 to 4.6 m of chalk with many large irregular flints; Micraster coranguinum and Bourgueticrinus sp. were obtained here. The disused large pit [TR 017 603], south of the London to Canterbury road, 0.5 km SSE of the Station showed a 12 m face, but largely inaccessible, though Conulus albogalerus was collected. The best section, however, was seen at Bushell's Pit [TR 019 606] 320 m SE of the Station, where the pit-faces showed 9 m of soft clean white chalk with nodular flints mainly scattered but with a conspicuous band about 3 m up. The following fossils were found: Micraster coranguinum, Echinocorys scutata, Conulus albogalerus, Conulus subrotundus (d'Orbigny) non Mantell, Conulus spp. and Bourgueticrinus sp. The old pit [TR 034 604] 550 m SSW of Ewell exposed 7.6 to 9.1 m of soft chalk with scattered flints; Conulus albogalerus, Crateraster quinqueloba and Bourgueticrinus sp. were found here. Between Faversham and Goodnestone chalk is at the surface in a few places northward of the main outcrop but was not exposed in any sections.

Chalk of the coranguinum Zone occurs again only as an inlier, along the axis of the Isle of Thanet anticline, occupying the valley north of Sarre. It was well exposed in the pit [TR 258 662] 275 m E of Down Barton, where 9 m of soft blocky chalk, with scattered large nodular flints at several levels, includes a band of abundant Conulus about 7 m down. Tests of Micraster sp. located about 3 m down were in a broken condition and apart from Conulus albogalerus the only other fossils seen were bryozoa and Bourgueticrinus sp.; the chalk and flints are very similar in character to those exposed in a pit about 0.4 km NE of Monkton church, on the Ramsgate (274) Sheet, recorded by White (1928, p. 40) and now known, from further fossil evidence and much-extended quarrying, to include above the coranguinum Zone a capping of Uintacrinus Zone chalk farther east.

From the road bank 1 km NE of Sarre only indeterminate crinoid brachials were obtained, together with Bourgueticrinus sp. and a fragment of Stereocidaris sp. It is clear, however, that the horizon is below the Uintacrinus Zone, which was identified by the presence of the zone fossil higher on the hillside about 0.4 km farther northeast, beyond the boundary with Sheet 274.

Uintacrinus socialis Zone

Probably no Uintacrinus chalk is present beneath Tertiary cover westward of Wear Farm, north of Chislet. The Chalk there is brought to the surface by the anticline through Chislet Marshes and Ford. About 230 m SW of Wear Farm a small fresh working in the west face of an old pit [TR 222 651] exposed 1.8 m of unevenly fracturing chalk with a band of very large semi-tabular flints. Fossils include Echinocorys scutata (a large variety), Bourgueticrinus spp. (numerous, attached to flints), Metopaster sp., and, rarely, plates of Uintacrinus. The horizon is thought to be very near to the base of the zone.

In the Isle of Thanet three pits at Sarre exposed the beds, and all three yielded Uintacrinus sp. In addition Porosphaera globularis, Bourgueticrinus sp., miscellaneous crinoid brachials and marginals of Chomataster sp. were obtained from the pit [TR 262 650] 275 m ESE of the windmill, which exposed 6 m of chalk with a few flints and some impersistent seams of brownish nodular chalk. The pit [TR 259 651] 100 m W of the windmill showed, near the top, about. 4.6 m of similar chalk, with Micraster coranguinum; an older part extends some 6 m deeper, reaching probably to the base of the zone, and at about 230 m W of the windmill were obtained Terebratulina striatula, Tylocidaris clavigera, Bourgueticrinus sp. and asteroid ossicles. The largely overgrown third pit [TR 257 652] exposed 4.6 m of firm slightly lumpy chalk at about 320 m WNW of the windmill; Actinocamax verus, Bourgueticrinus sp., and ostreids were found. An old pit [TR 253 668] 600 m west-by-south of St Nicholas Court and another [TR 256 676] east of the farm at Chambers Wall both yielded Uintacrinus sp. in firm chalk with scattered flints. At the latter locality Terebratulina striatula and Bourgueticrinus sp. were also got. Rubbly chalk with hard creamy lumps was poorly exposed [TR 259 678] at Bartletts, bordering the Alluvium north of Potten Street. SCAH

References

DEWEY, H., BROMEHEAD, C. E. N., CHATWIN, C. P. and DINES, H. G. 1924. The geology of the country around Dartford. Mem. Geol. Surv. G.B.

HAWKINS, H. L. 1918. Notes on the geological structure of the Vale of Kingsclere. Proc. Hampshire Field Club, Vol. 8, Part 2, pp. 191–212.

ROWE, A. W. 1900. The Zones of the White Chalk of the English Coast, I–Kent and Sussex. Proc. Geol. Assoc., Vol. 16, pp. 289–368.

WHITE, H. J. O. 1928. The geology of the country near Ramsgate and Dover. Mem. Geol. Surv. G.B.

Chapter 5 Tertiary

Introduction

Most of the land within the area is occupied by Tertiary rocks, of Palaeocene and Eocene age, and at one time these extended over the whole of the district before being partially removed by denudation. The upward sequence represents a cycle of deposition on a somewhat broader scale than the marine and estuarine alternations in areas farther west. The Thanet Beds are marine; the overlying Woolwich Beds are marine with some estuarine or possibly deltaic features, and locally a lagoonal phase at the top; the Oldhaven Beds are a shallow-water marine deposit with some characteristics foreshadowing London Clay deposition, which was determined by deeper water into which large rivers brought an influx of muddy sediments from a deeply denuded land surface; a return to shallower water conditions was heralded by the incoming of the sandy sediments that now form the Claygate Beds and Bagshot Beds.

The definition of the boundary between the Palaeocene and Eocene periods is currently under debate. The 'Palaeocene' Period was defined by Schimper (1874) based primarily on palaeobotanical studies in the Paris Basin. In this paper, the London Clay was placed in the Eocene although by his definition the Ypresian Stage (equivalent to the London Clay) is included within the Palaeocene. More recently Curry (1958, 1966) and Cooper (1976) have placed the upper boundary of the Palaeocene at the top of the Oldhaven Beds and work on dinoflagellate assemblages (Harland, personal communication, 1976) in the North Sea has indicated the Palaeocene–Eocene boundary to be at the base of a series of bedded tuffs which are equivalent to beds in the lower part of the London Clay in the present district.

Within the series are erosional breaks of a small and local character, but that at the base of the Oldhaven Beds exceptionally cuts out most of the Woolwich Beds locally inland.

For an account of the sequence from Thanet Beds to Bagshot Beds in its regional setting the relevant modern summary is an historical and general description of the Palaeogene beds of south-east England by Curry (1965, pp. 151–173), wherein full reference is made to previous work on the macro- and micro-fauna and on the flora of the beds.

A great deal of our knowledge of the Tertiary strata of the present area originates from the work of Prestwich, Whitaker, Gardner and many others, including that of the late A. G. Davis and of the late A. Wrigley. Their observations dealt primarily or exclusively with the coast sections; the six-inch survey provided an opportunity to elucidate the inland developments more fully. A magnificent section (see pp. 35, 41, 49) at Shelford, near Sturry, has been exposed for half a century and was recorded in detail by Mr H. J. Gamble in 1968. SCAH

Thanet Beds

The Thanet Beds crop out in the Faversham district in the south-west part of the present area, eastwards of Herne and Herne Bay, and along the sides of the Great Stour valley near Westbere and Stodmarsh. They are present beneath the Drift under considerable areas of the Chislet Marshes and the Alluvium of the Great Stour, retaining throughout their essentially fine sandy character. The thickness is generally from 30 to 33.5 m but, because of the transgressive nature of the overlying Woolwich Beds, the formation thins at the outcrop on the south and west to about 24 m at Beacon Hill, west of Faversham, and apparently to little more than 18 m locally at Goodnestone.

Classic accounts of the Thanet Beds of Kent, under the term Thanet Sands, were given by Prestwich (1852, p.235) and of the Reculver coast section in particular by Gardner (1883, p. 197). Other descriptions of interest are by Osborne White (1928, p. 45) and by Whitaker (1872, p. 55); the latter discusses variations in the beds in Kent and the earlier theories on the origin of the basal bed (later termed the Bullhead Bed) and its relation to the Chalk. The late A. Wrigley (1949, p. 41) has advanced views that this bed, predominantly comprising unworn green-coated 'bullhead' flints in a glauconitic clay matrix, marks a redeposited 'clay-with-flints' on an old land surface; that the material of the bed generally is derived from Lower Green-sand and Gault, and was laid down in a shallow sea; and that the marine type continues into the Woolwich Beds without any major break. Thanet Beds of this area were also described by Wooldridge (in Dewey and others, 1925, p. 266).

Towards the close of the period it is evident that deposition in the Thanet Beds sea was irregular. For instance, near Goodnestone on the south, evidence points to penecontemporaneous erosion which allowed only a few centimetres of shelly sand to be laid down and preserved; whereas on the coast the succession shows that there continued to be deposited a considerable thickness of sandy mud, of which a proportion is now represented by at least 1.8 m of clayey sands crowded with mollusca.

Whitaker's five subdivisions of the Thanet Beds (1866, p. 405; 1872, p. 56) are not distinctly represented in this area, except the basal (Bullhead) bed 'a'; this may be followed by clay, fine silty loam, bluish sandy marl or 'sharp' sand, sometimes with ironstone and calcareous sandstone layers in the top half; but apart from the fact that the lower beds tend to be clayey and the upper dominantly sandy and often shelly it has not proved possible to subdivide the series. Lateral variations are considerable, if local, and the litho-logical summary given below must be regarded only as an approximation. Sandrock or sandstone doggers are rarely present and small pebbles are met with only occasionally and at various levels. Much of the formation as sampled when weathered, wet, or obtained from boreholes, has the appearance of a very sandy blue clay or dark 'dead' sand.

In the field it has proved quite feasible to separate the Thanet Beds from the somewhat similar Woolwich Beds that overlie them, although Collins and Gill (1923, p. 310) and Wooldridge (in Dewey and others, 1925, p. 268) were unable to do so. By close examination of the lithology in inland sections, however, the basal rusty glauconitic bed of the latter formation (see p. 32) is usually traceable, especially where a few pebbles occur, and the Woolwich sand generally is rather coarser. On the coast the sands of the lower part of the Woolwich Beds are indeed more similar to the Thanet sands but there the densely concentrated shelly top of the Corbula Bed forms a convenient dividing line, even though palaeontologically the beds are inseparable (Gardner, 1883, p. 204; Wrigley, 1949, p.43) and Corbula itself ranges down some 6 m lower. The term Corbula Bed as used in the earlier literature has been applied somewhat loosely, to variable thicknesses of beds containing Corbula regulbiensis, some of them undoubtedly assignable at the coast to the Thanet Beds, as variably exposed from time to time. Inland sections that show a coarsening of the sand at the top which approaches the Woolwich type, are, however, occasionally met and separation of the two formations may be difficult in these circumstances (Whitaker, 1866, p. 409; 1872, p. 101). Definition of the base of the Woolwich Beds on lithological and faunal evidence is discussed on p. 31.

A shelly bed at Goodnestone (Whitaker, 1866, p. 409; 1872, pp. 87, 573; Wooldridge, in Dewey and others, 1925, p. 268) appears to correspond faunally with shelly sands in the Thanet Beds some 3 to 5 m below the top of the formation where it is exposed in the coast section west of Reculver; but another at Waystreet Farm (formerly Oakwell), about 1.5 km eastwards (Prestwich, 1852, p. 246), containing common Corbula regulbiensis, has been excluded from the Thanet Beds and correlated with the Corbula bed of the coast section that is here assigned to the base of the Woolwich Beds. Prestwich (1854, p. 109) was himself subsequently inclined to favour such correlation, but thought it should also apply to the bed at Goodnestone. Investigations by Haynes (1956; 1958, pp. 83–84, 87, 89) on Palaeocene foraminifera from the Thanet Beds have included studies of the Reculver coast section. The conclusion that the Thanet sea was relatively cool is supported by the absence both of larger and of porcellanous foraminifera and by the low average size of the fauna. Deposition was in shelf waters of shallow to moderate depth. The coarsening shown by the sands at the base of the Woolwich Beds is sufficient to cause disappearance of the Thanet microfauna. Indeed, later studies by Haynes and El-Naggar (1964, pp. 354–356) have emphasised that the occurrence of even a sparse planktonic fauna in the Thanet Beds ('Reculver Silts' division) of East Kent may be explained by derivation from reworked Campanian and Danian deposits. In contrast the benthonic fauna is abundant and is marked by the absence of tropical species. Blondeau and Pomerol (1969, pp. 447–448) have described the occurrence of heavy minerals in the Thanet Beds of Reculver and Bishopstone Glen, and elsewhere, noting a diminution upward of sphene and epidote accompanied by the appearance of anatase and brookite.

The following is a summary of the general lithological sequence for the Thanet Beds.

Details

The outcrop near Faversham is comparatively free from Drift only on the west near Luddenham and Beacon Hill and on the east near Hernhill. On the south side of the town there are a number of small outliers.

Westward of the valley running through Syndale Bottom to the creek at Oare the wide tract of Thanet Beds afforded a number of exposures, more especially of beds near the top of the formation. At Beacon Hill sands of these beds are similar in the road cutting [TQ 986 613] and in an old pit [TQ 984 610] by the farm (formerly called Sand Hills) O. 4 km SSW of the Hospital, where some 1.5 m of greyish sand, mainly fine-grained, showed a brown-cemented top. Exposures of these sands were included by Hughes (in Whitaker, 1872, p. I 61) in the Woolwich and Reading Beds, though he was somewhat doubtful about their true horizon. In the railway cutting [TQ 988 618] just north of Beacon Hill, however, the separation of Woolwich and Thanet Beds was clearer than when recorded by Hughes, about 1 m of the coarser Woolwich sand (see p. 32) resting on poorly exposed buff-grey slightly glauconitic Thanet sand becoming fine-grained, and, at the bottom of the cutting, green and clayey (Whitaker, 1872, p.80). Grey glauconitic sand and loam at the bottom of the Thanet Beds was seen [TQ 975 612] adjoining Barbary Farm. Northward of this the Thanet Beds are clayey and loamy, forming a thin cover to the Chalk and overlapped by loamy drift; there is evidence that a small outlier occurs under this about 0.2 km WNW of Elverton. At the top of an old chalk pit [TQ 982 621] adjoining Stone Farm (see p.25) was seen about 1.8 m of grey, buff and yellowish rather loamy sand with the basal Bullhead Bed consisting of green-coated and manganese-stained nodular flints, which tend to coalesce.

The wooded tract (known as 'Bysing Wood') that occupies the high ground southward of Nash's Farm, includes a number of exposures of Woolwich Beds and Thanet Beds described in some detail by Hughes (in Whitaker, 1872, pp. 80, 161, 162). The road cutting [TQ 994 619] 275 m SW of the crossroads in the centre of the wood exposed 1.5 m of fairly fine grey-buff sand of the Thanet Beds beneath iron-cemented sands with pebbles of the Woolwich Beds (see p. 32). Just south-east of the cross-roads [TQ 996 621] 0.9 m of Thanet Beds beneath the Woolwich pebble bed (see p. 32) were seen to be slightly loamy, streaky and locally cemented with iron to a soft sandstone, and to become paler and finer-grained downwards. About 100 m NW of the crossroads [TQ 995 623] the Thanet sands again appear beneath the Woolwich Beds, the top 1.5 m being highly glauconitic, loamy and rather coarser-grained than the 4.6 m of grey-buff sand and soft sandstone seen below. A sand-pit [TQ 999 625] at the farther crossroads on the north-east side of the wood exposed 4.6 m of fine-grained grey-buff slightly glauconitic Thanet sand, mainly 'sharp', with irregular brown lenses up to 0.6 m thick. The section also exposed the basal Woolwich Beds in the south-west face (p. 32). Some 15 m lower in the series, a roadside pit [TR 000 620] 320 m SSE of the last exposed 1.8 m of fine-grained loamy sand with firmer brown beds, overlapped by drift. Hughes (in Whitaker, 1872, p.80) mentions also another section, at a higher level, with less clayey beds; probably this refers to the sandy bank, now overgrown, 140 m NNE. On the east side of the road [TR 007 632] 165 m SW of Oare church 3 m of fine variegated sand, loamy in the lower part but 'sharper', coarser-grained and iron-cemented above, were seen underlying the basal Woolwich Beds (see p. 32).

Around Judd's Hill glauconitic clayey loam at the base of the Thanet Beds was noted in the main mass and in the small outlier to the south-east. Another small outlier of glauconitic Thanet loam occurs between Ospringe and Faversham.

West of Faversham, in the Davington Hill area the Thanet Beds are largely covered by drift. They appear at the surface near the windmill on the road to Oare, and on the high ground of The Brents district, but soon disappear again beneath extensive spreads of brickearth. Hughes (in Whitaker, 1872, p.80) saw clayey loam in a section, now obscured, over 0.4 km SW of Davington church.

The outlier that extends southwards from Faversham Station is cut by the road branching south from the main road to Canterbury, exposing 1.8 m of clayey loam overlying the Chalk. Hughes, in MS, recorded a section north of the main road in which Thanet sands with a basal 1.2 m of clay and a bed of green-coated flints were well exposed where dug below brickearth. Under the flints black and green clay was shown to rest on decomposed chalk associated with amorphous earthy material. Another outlier occurs 0.4 km to the east of the Station.

The main mass is cut by the railway east of Faversham both on the Canterbury and Whitstable branches. In the former the Chalk is reached some 1.8 m down in the cutting except nearing the Canterbury road, where a small fault [TR 027 603] throws Thanet Beds down below rail level on the south-east. The section showed grey and rusty clayey sand and loam, but was seen in a fresher state by Whitaker (1872, p. 85), who described the higher part as a light-coloured sand. He also mentions two cuttings on the Whitstable branch, but the only exposure seen in 1939 was at the bridge [TR 026 610] near Ladydane, where beds near the base of the formation consist of grey, blue and rusty-weathered fissile clay with a variable sand content. An old brickworks [TR 023 609] north of the line and westwards of this bridge exposed 0.6 m of highly glauconitic loam with the Bullhead Bed above the Chalk; eastward of the Chalk junction the overlying brickearth was seen to pass down very gradually into undisturbed Thanet Beds, and a local section [TR 024 610] entirely in the latter showed 1.2 m of grey, bluish and brown slightly sandy clay, weathering like a brickearth into rectangular masses, overlying 0.6 m of glauconitic loam and sandy clay.

Adjoining Faversham on the north-east side Head Brickearth and Alluvium cover the Thanet Beds, but according to Hughes the latter itself was formerly dug for brickmaking (see Whitaker, 1872, p. 85). A trial boring [TR 024 617] at Abbey Fields Sewage Pumping Station, 1.2 km NE of the Railway Station, after passing through 2.7 m of brickearth continued through 12.2 m of Thanet Beds to reach the Chalk, proving the following beds, essentially clayey below the top 2.1 m:

The Bullhead Bed occurs in the road cutting at points 140 m NNW [TR 035 610] and 275 m ENE [TR 038 610] of Ewell. A section of the top beds together with overlying Woolwich Beds (see p. 33) was seen in the cutting on the same road farther east (044 609] near the junction with the road down Head Hill to Goodnestone, comprising 0.05 to 0.15 m of glauconitic sandy rock, crowded with shells, overlying 1.8 m of fine grey and yellowish glauconitic loam with a little thin ironstone at the top. The shell bed is the silicified bed referred to by Prestwich (1854, p. 109, footnote) as 'nearer to Faversham', and by Whitaker (1872, pp. 87, 573), who records many fossils from the section including Astarte tenera. The common occurrence of the latter lends support to the view that this particular bed, but not the one examined by Prestwich at 'Oakwell' (see p. 27), may be a somewhat condensed representative of the richly fossiliferous zone (with an Arctica bed) which has been found on the coast some 3 to 5 m from the top of the Thanet Beds; evidence from a well-boring about 0.4 km to the east suggests that the Thanet Beds are there reduced to as little as 18.7 m. About 0.8 km SSW orange-mottled and greyish loam is cut by the main coastal road. The railway cutting [TR 051 622] at Graveney formerly showed a good section of Woolwich Beds and Thanet Beds (Whitaker, 1872, p. 163); the light grey fine-grained sand beneath the layer of black flint pebbles is now regarded as the top of the formation. In MS, Whitaker described the sand as patched with yellow and underlain by clayey sand on the south. Yellowish sand speckled with glauconite is a common surface appearance of the higher Thanet Beds in this district. SCAH

A section [TR 060 613] along the coastal road 0.2 km S of Waystreet Farm showed 3 m of glauconitic sand, somewhat clayey and impregnated with iron towards the top, beneath the Woolwich Beds (see p. 34), and bordering the alluvium just west of this locality Whitaker (1872, p.87) recorded fine-grained sand with shells 'south-west of Oakwell', but another hard shell bed he also describes in this area is at a higher level and is now placed at the base of the Woolwich Beds. About Hernhill two valleys cut deeply into the Thanet Beds, the clayey nature of which tends to make the land boggy. The sand-pit [TR 064 606] 100 m SW of Hernhill church is mainly in Woolwich Beds (see p. 33) but on the south-east, at the entrance, 1.5 m of finer-grained sand, grey to orange-brown, with minor iron-cementing, represents the Thanet Beds; these were also seen by Whitaker (1872, p. 165) in the adjoining lane cutting. About 0.8 km SW of Hernhill the lane leading from the crossroads down to the stream in the valley east of Fairbrook Farm exposed buff and orange glauconitic sands [TR 058 603] 140 m NW of the crossroads. The cutting down the hill at one time exposed, according to Whitaker (1872, p.87), fine-grained sands, shelly sandstone, shelly sandy marl and clayey sands. The sandstone 'about half-way down the hill' was 'full of silicified shells'; the bed may be the equivalent of the one at Goodnestone, and silicified wood 'found east of Fairbrook' may probably have come from it. SCAH, JRE

Eastwards the Thanet Beds are next exposed in the valley of the Great Stour near Sturry, showing here and there on the left bank but mostly covered by Head Brickearth. Below Woolwich Beds in the large sand-pit at Shelford (p. 35) a recognisable Arctica bed was encountered in a borehole put down in 1968 (Gamble, 1972, p. 475). Where gravel is dredged in the alluvial tract the associated 'bungum' consists either of alluvial clay or the underlying grey fine silty loam of the Thanet Beds. In the south-eastern part of the large gravel pits [TR 176 606] 0.4 km NW of the railway station 3.7 m of grey speckled fine-grained sand were seen beneath the gravel, and a metre or so of yellow and grey sand beneath the Woolwich Beds was noted in the old gravel pits 320 m NNE [TR 179 607] and 550 m NE [TR 181 608] of the station. Similarly, about 3.7 m of speckled sands with soft iron-impregnated sandstone were seen beneath the Woolwich Beds (see p. 36) in the southern part of the old pit [TR 185 610] 1 km NE of the station. Of two old pits at Westbere the first [TR 193 611], 140 m ENE of the church, showed, beneath the Woolwich Beds, 2.1 m of light-speckled fine-grained sand on 1.5 m of yellowish and brown fine-grained sand, and the second [TR 195 611], 210 m E of the church, 3 m of firm yellow fine-grained sand. Beyond Westbere the Thanet Beds are obscured by Head Brickearth and Alluvium.

In the Stodmarsh district large spreads of brickearth and gravels again overlie the Thanet Beds, but the sand is at the surface bordering the Woolwich Beds on the ridge west-south-west of Stodmarsh and in a small tract on the hillside 0.4 km SSW of the village. About 1.5 m of glauconitic sand with a bed of soft ferruginous sandstone was exposed in an old pit [TR 216 603], below the 50 ft (15.2 m) contour, 0.5 km WSW of the church and also in the bottom of the pit [TR 227 604] in gravel and Woolwich Beds (see p. 36) at the road fork 0.4 km SSW of Grove Hill.

On the east bank of the Little Stour a very narrow outcrop of Thanet Beds appears above the Alluvium south-west of Preston Court.

At Elmstone, the village 1.2 km SE of Preston, there is a small inlier of Thanet Beds, formerly exposed 100 m S of the church in a pit [TR 261 602] mentioned by Whitaker (1872, p. 173]. The 0.9 to 1.2 m of light-coloured sand are now referred to the top of the Thanet Beds on the evidence of detailed mapping.

The islands of Thanet Beds in the alluvial tract which extends northwards from Grove through Chislet Marshes to the coast consist mainly of buff fine-grained sand, somewhat clayey near the Stour and the River Wantsum where the lower beds appear and the Chalk is approached. Even if not strictly in situ, mounds which may have been artificially raised indicate the nature of sub-alluvial material, excavated from the deep ditches. They occur in strength south-south-west of Sarre and north-east of Marshside but are absent north-east of Chitty where Chalk underlies the Alluvium. Trial-borings east of the Wantsum near Coldharbour Sluice show that the base of the Thanet Beds falls fairly rapidly westward from the junction with the Chalk (beneath the Alluvium), one borehole [TR 257 692] not proving Chalk until a depth of 24.5 m. The 20.9 m of Thanet Beds recorded consist of sands, partly shelly, with 4.4 m of soft blue clay at the bottom and the basal Bullhead Bed 0.46 m thick.

The Thanet Beds have a broad outcrop on the lower ground north-west of Chislet and near Ford and Marshside, associated with the valley and anticlinal axis through Herne. In the chalk pit [TR 222 651] 180 m SSW of Wear Farm (see p. 25) Whitaker (1872, p.89) saw on the south side a section of about 2.7 m of loamy and clayey Thanet Beds with green-coated flints, tabular flint and brown ferruginous earth resting on a disturbed Chalk surface. Yellowish buff clayey sand occurs in places below the drift in another old pit [TR 224 650] 180 m ESE of this but may not be strictly in situ. A section in this pit is figured by Dowker (1864, p.340). Whitaker (1872, p.90) recorded marly sand, with the basal bed, resting on the Chalk, in an old pit 500 m NNW of Wear Farm, and similar sand (firm and micaceous) with casts of Cyprina etc. in the adjacent road ascending the hill northward. In the valley at Ford (formerly Hoathborough) Whitaker (1872, p. 169) noted fine-grained Thanet sand. Subsequently a sand-pit [TR 204 659] opened on the west side of the road 230 m north-west of the Manor House showed the following section:

South of Reculver a comparatively wide tract of Thanet Beds owes its presence to another anticline. The railway cutting near Brook Farm (north-west of Chislet Windmill) formerly exposed Thanet Beds in its eastern part, recorded by Whitaker (1872, p.90) as fine-grained sand with brownish layers overlying clayey sand. At the road junction 0.4 km NW of Brook Farm Whitaker noted light brown slightly clayey fine-grained sand and a marly fossiliferous bed at Old Barns, a little way down the road to Reculver. SCAH

The coast exposes Thanet Beds westwards from Reculver to Bishopstone (Plate 2), and the whole section has been much visited; for example by the Tertiary Research Group and the Geologists' Association jointly in June 1974. It has been described many times; the Thanet Beds are dealt with substantially by Prestwich (1852, p.262, pl. xv), Dowker (1864, p. 341), Whitaker (1872, p.171) and Gardner (1883, p. 202). Seen in 1938 the cliff 550 m westward of the ruined church showed, beneath the Corbula Bed (grouped with the Woolwich Beds) (see p. 37) some 5 m of greenish buff sand, shelly in the lower 1.8 m, with a 0.3 m layer of calcareous doggers at the bottom. About 100 m farther west the Woolwich Beds are absent where a drift-filled valley is reached, and the section seen was as follows:

About 0.8 km beyond this the section below the Woolwich Beds was:

About 100 m beyond the ravine west of Bishopstone the westerly dip carries the Thanet Beds below beach level. Whitaker noted a very few flint pebbles at the top of the Thanet Beds on the coast, but found separation from the Woolwich Beds sands indistinct except by tracing the Corbula Bed. He describes the doggers as concretionary blocks of sandstone, noted later by Wooldridge (in Dewey and others, 1925, p. 272) as large tabular masses of hardened sand, up to 0.3 m thick, below which occur stiff marls with Cyprina and Pholadomya. The doggers serve as a guide in picking out the basal Woolwich bed (see p. 37) some 5 m above them. The shelly sands overlying the doggers are clayey or marly and at some spots contain a particularly rich fauna (see pp. 27, 28, 52) including Astarte tenera. Gardner (1883, p. 204) described these fossiliferous beds in some detail but there is no indication that Prestwich (1854, pp. 111–112), who described the Corbula Bed (without A. tenera) at the base of the Woolwich series, intended to include a lower shelly bed with the latter, as Gardner implies. SCAH, SB

Gamble (1968, p. 591) noted that in 1966 there remained exposed only a few small patches of Arctica Bed [in the sands below the course of sandstone doggers]. Such shelly sands tend to be lenticular and very variable in themselves, as well as to depend on foreshore conditions and cliff erosion for their aspect at any time. As Mr Gamble remarked, the orientation and distribution of bivalves in these silty beds reflect their local palaeoecology. In 1959 Gurr (1963, p. 420) had seen a bed crowded with Arctica morrisi at 5.2 m below the Corbula Bed, and this was still well exposed in 1964, yielding examples also of Cucullaea decussata Parkinson, Arctica planata J. Sowerby and Dosiniopsis bellovacina (Deshayes) (Stinton, 1965, p.176).

Dr W. A. Read reports that of the six palaeontological units distinguished by Mr J. Cooper and Mr D. J. Ward (of the Tertiary Research Group) below their defined Corbula regulbiensis Bed, the lower four seen in June 1974 were lithologically distinct, including the 'Reculver Tabular Band' (calcite cemented) then seen some 7.5 m above the base of the section; the upper two, however, lay within a single set of foresets and must therefore have been deposited simultaneously. The strata concerned are bioturbated silty sands with lignitic concentrations along the foresets. Mr Ward and his colleagues have established their stratal section (upwards to the Basement Bed of the London Clay) in great detail by precise collecting and utilising accurate measurements on the foreshore at low tide. It was clear, for example, in September 1975 that modification of the coastal erosion cycle consequent upon artificial stabilisation of the landslipped cliffs (p. 108) has now allowed the advantage of an extensive and largely mud-, sand- and shingle-free flat to develop for a period. The full stratigraphical results are published separately (Ward, 1977) and reasons are stated for preferring an alternative line of separation between the Woolwich Beds and Thanet Beds as displayed at the coast (see also p. 37). Following the usage adopted throughout the present memoir and also in that for the Canterbury district (Smart and others, 1966), however, which is based on a mapped lithological datum line correlated over wide areas inland, the uppermost limit of the Thanet Beds is here taken below a bed of dense silicified Corbula shells, 0.3 m thick, in a rusty-weathered compacted glauconitic sand, that characterises the top of the glauconitic silty Corbula regulbiensis Bed (1.14 m thick) of the Tertiary Research Group's sequence. Corbula is also abundant below this in their Tornatellaea parisiensis Bed, 0.6 m thick. SCAH

Woolwich Beds

The outcrop of the Woolwich Beds follows fairly closely that of the Oldhaven Beds, which in turn, on emerging from beneath thick London Clay cover southward of Sheppey and around the Blean area, follow the London Clay base. The Woolwich Beds outcrop is very narrow on the steep valley side near Sturry and Westbere and around Preston the beds are almost entirely drift-covered. Their thickness at outcrop is generally 7.5 to 9 m but amounts up to 12 m are recorded from boreholes through the London Clay of Sheppey and the Blean. A thinning of the Woolwich Beds due to the transgression of the overlying Oldhaven series is indicated by mapping southward of Goodnestone.

Prestwich first described in detail the Tertiaries at Herne Bay and a description will be found in Part II of his general account of the Woolwich and Reading Series (1854, p. 110). The Survey memoir by Whitaker (1872) is a source of many careful descriptions and has been drawn on considerably for the present detailed account. In his account for the areas to the east, Osborne White (1928, p. 56) followed Whitaker (1866, p. 410; 1872, p. 171) in stressing the difficulties in finding a dividing line from the Thanet Beds. Detailed surveys in recent years, however, have shown that a mappable boundary can be traced satisfactorily in most of the appropriate areas of north-east Kent. Wrigley (1949, p. 43) has shown how the Woolwich Beds, with the basal bed of Corbula regulbiensis, first defined by Whitaker (1866, p. 410), from which many silicified shells have been obtained, may be interpreted as a continuation of the marine sedimentary cycle from the Thanet Beds into more variable cross-bedded estuarine, or possibly deltaic, deposits. Although the beds may be regarded as occupying only one sedimentary phase and show almost no palaeontological distinctions above and below the junction (see also Gardner, 1883, p. 204), the Woolwich Beds sands nevertheless have a character of their own, and a distinctive basal type which is lithologically demonstrable throughout the area (see also p. 32). Other opinions have been expressed by Collins and Gill (1923, p. 310), by J. E. Cooper (1934, p. 5) and by Wooldridge (in Dewey and others, 1925, p. 268); Prestwich (1854, p. 112), however, recognised the essential lithological differences, although the faunal similarities were not appreciated at that date. He pointed out that any indistinctness of the separating surfaces reflects only the nature of soft sands stirred up and gently intermixed by currents in a shallowing sea. He noted that the sands of the Woolwich Beds have more green sand and disseminated flint pebbles and are more siliceous and generally variable, even on the coast, with the green sandy Corbula Bed characterising the base. In this bed the Corbula shells are perfectly preserved but associated forms are imperfect and broken. The inference is that the latter were dead when washed into the places occupied by colonies of Corbula (Cooper, 1934, p. 7), a feature which indicates shallowing of the sea and a minor stratigraphical break at this horizon. Additional to the coast section this bed is known to occur inland near Fostall (p. 34) and Ford (p. 37).

The important molluscan fauna of the Corbula Bed is sometimes classified and described with that of the Thanet Beds, with which it has close affinities (see for example B.M. (N.H.) 1968, pp. 7, 58), and some workers (e.g. Gurr, 1963, p. 420) have preferred to allocate the Bed to the Thanet Beds on local stratigraphic grounds (see below). This is the usage that is advocated by the Tertiary Research Group from their detailed studies of the coastal exposures (p. 37).

Arguments on general grounds for retaining the name Woolwich Beds for the equivalent sands at this horizon in East Kent were early emphasised by Whitaker (1885, p. 170) even though he thought the basal bed might fail. The term 'Bishopstone type' has been used by E. I. White (1931, p 4.) to distinguish the essentially marine sands of East Kent from the definitely lagoonal 'Woolwich type' of the western part of the county. From studies of the fish fauna from a distinctive local bed (clayey, sandy, variably pebbly and 0.23 m thick) in the lower part of the Woolwich Beds westwards of Bishopstone Gap, Gurr (1963, p. 420) concluded that this bed represents the Woolwich Bottom Bed of north-western Kent and adopted it as the base of the Woolwich Beds while recognising the presence of the Corbula regulbiensis Bed some 1.8 m below it. The fish bed has not, however, been definitely traced inland; beds similar in lithology may be recognisable locally, and as such could merge with the frequently clayey and slightly pebbly basal Woolwich Beds recorded in the course of the six-inch survey; neither this fish bed nor the Corbula Bed were detected at Bishopstone Glen in 1966 (Gamble, 1968, p. 591), but both were well exposed in 1974–75 (p. 37).

Another view was adopted by Hester (1965) in a general account of the Woolwich and Reading Beds. While regarding the Corbula Bed as the stratigraphical base he suggested that the glauconitic sand, which Pitcher and others (1967, p. 7) followed in accepting as the lateral equivalent of the entire Woolwich and Reading Beds farther west, is equivalent to no more than the Bottom Bed of that formation as it occurs in varied succession around and to the west of London. He produced evidence in favour of presuming that the higher beds have been removed by pre-Oldhaven Beds erosion. Hester used the term 'Woolwich type' in a restricted sense to denote the essentially estuarine deposits of north-western Kent. As intermediate types are not found in the present area it is desirable for descriptive purposes to retain, however, the unit 'Woolwich Beds' for the essentially shallow-water marine sands of north-eastern Kent, following the usage implied by Prestwich (1854, pp. 112–113, 131–132, 170, p1. i) and adopted throughout by Whitaker (1866, pp. 420, 433–434; 1872; Whitaker and Dowker, 1885), whatever may be their stratigraphical range compared with the more varied beds farther west.

In the area of Sheet 273 there are no indications of the presence of any non-marine, stratigraphically higher, Woolwich Beds. The detailed account which follows, however, refers to considerable evidence of erosion by the Oldhaven Beds sea that points to the cutting out of Woolwich Beds either by overlap, or by local channelling or by uniform, if local, shallow-water erosion of a characteristic sandstone bed near the top of the Woolwich Beds.

The work of H. J. Gamble on stratigraphy, sedimentology and vertebrate palaeontology of the Thanetian–Sparnacian sequence (Gamble, 1968, pp. 587–593; 1970, pp. 397–398; 1972, pp. 471–478) has added much information on the Woolwich Beds of East Kent. He preferred the term 'Woolwich Bottom Bed' to be restricted to the pebbly bed which, with coarse-grained sand, clay, etc., is taken as the basal bed in the present account. Both in the Thanet Beds below this unconformable junction and in the 'Woolwich Marine Beds' above, occur the lined or unlined burrows (Ophiomorpha nodosa) of a callianassid crustacean, described by Kennedy and Sellwood (1970, pp. 99–110). Ophiomorpha is an undoubted marine indicator; in the shallow marine, sublittoral environment of the Woolwich Beds the burrows with cemented walls of soft carstone form a distinct litho-logical unit at Shelford (p. 35), though at Bishopstone (p. 37) the tubes are unlined in the finer-grained and more competent sand (Gamble, 1970, pp. 397–398).

The typical lithology of the Woolwich Beds is a series of generally coarse-grained, glauconitic, cross-bedded sands, with a 'pepper-and-salt' appearance and containing ferruginous beds with laminated, concretionary and tubular ironstone (see Wooldridge in Dewey and others, 1925, p. 269). The thin seam of small pebbles at the base is locally very tenuous, and is commonly replaced laterally by hardened sand with Corbula. It is invariably associated with highly glauconitic sand and, inland, with clayey seams and ironstone. Records of a metre or so of such basal clayey sands sometimes serve as a useful guide in interpreting borehole records through the Tertiaries. A bed of mauve-grey sandstone developed within 1.5 m of the top of the formation (and occurring as derived boulders in the overlying Oldhaven Beds) is well developed in the Hernhill district. This is the bed recognised by Collins and Gill (1923, pp. 305–307); it also persists westward, and beyond Faversham 'firm, partly hardened sand, of a purplish tint' has been recognised in a boring [TR 002 654] at Oare Powder Works. In the Stour valley and east of the Blean, however, it is not represented, except as derived blocks in the Oldhaven Beds at Sturry. These features suggest particular shallowing of the sea and perhaps the emergence (or near-emergence) of a land-mass nearby on the south and west which may have generally controlled the thinning by erosion of the Thanet Beds and Woolwich Beds, as well as determining subsequently a local littoral facies of the Oldhaven Beds developed very strongly near Selling, on the Canterbury (289) Sheet (Smart and others, 1966, pp. 181–182). The following is a generalised succession of the Woolwich Beds for the area:

Details

North-west of Faversham the Woolwich Beds emerge from below the Alluvium of Luddenham Marshes and present a relatively broad outcrop north-west of Oare which narrows down again before the beds reach the Alluvium north-east of that place. A series of small outliers occur on the hills south-west of the main outcrop.

On either side of the railway cutting just north of Beacon Hill coarse-grained Woolwich Beds sand occurs capping the hill (Hughes in Whitaker, 1872, p. 161); about 1 m of iron-stained coarse-grained sand was seen on the south side in 1938.

In two outliers in the wooded area (known as Bysing Wood) southward of Nash's Farm exposures of the Woolwich Beds sands, with underlying Thanet Beds (see p. 27), occur in road cuttings and have been described in detailed sections compiled by Hughes (in Whitaker, 1872, pp. 161–162). The cutting [TQ 994 619] 275 m SW of the crossroads in the centre of the wood exposed basal Woolwich Beds of the southern outlier as follows:

In the northern outlier the section [TQ 996 621] just south-east of the crossroads showed beneath the drift (see p. 69) about 1 m of coarse-grained brown ferruginous glauconitic sand with a 0.15-m bed of small pebbles, associated with some clay at the top, resting on the Thanet Beds. About 100 m NW of the crossroads the following section [TQ 995 623] was seen in the road cutting:

The outlier has a narrow north-easterly continuation, and the road cutting [TQ 998 624] 370 m NE of the above crossroads showed the following:

Hughes noted a few pebbles at this locality but the section as a whole was then obscure. The adjacent sand-pit [TQ 999 625] in Thanet Beds (see p.28) was in 1951 seen to expose a thin but very distinct basal pebble bed at the extreme top on the south-west.

No sections were seen in the tract occupied by coarse-grained sands of the Woolwich Beds north-west of Oare, but near the junction with the Thanet Beds there are indications that the sands become very clayey and glauconitic. Near Oare church the Woolwich Beds emerge from beneath gravel and brickearth and occupy the lower part of the west bank of the Oare Creek valley before disappearing under the Alluvium. The section [TR 007 632], noted under Thanet Beds, on the east side of the road 160 m SW of Oare church exposed 0.3 m of speckled sand with a band of small black pebbles overlying the Thanet Beds sands. About 30 m farther north-east the basal Woolwich Beds consist of 0.3 m of purplish ironstone overlying 0.3 m of coarse-grained, highly glauconitic clayey sand with some ironstone and a bed of tiny pebbles at the base.

North-east of Faversham the Woolwich Beds reappear from below the Alluvium south-east of Nagden, forming a steep bank of coarse-grained brown glauconitic sand, with ironstone towards the top which probably marks the uppermost part of the division. Similar coarse-grained sand is found southward of Sandbanks but around Broom Street the outcrop is covered by brickearth. The railway cutting [TR 051 622] at Graveney afforded to Whitaker 1872, p. 163) a section of Woolwich Beds and Thanet Beds in which the base of the former may now be placed at the layer of scattered black flint pebbles. Immediately above, the clayey sand with layers of ironstone is also quite characteristic of the basal beds in the area, and passes up into coarse-grained 'sharp' sand.

A long narrow spur of Woolwich Beds capped in places by Oldhaven Beds extends southwards past Goodnestone and beyond Head Hill. The section in the cutting [TR 044 609] on the Faversham road near the 'T'-junction with the road to Goodnestone was seen as follows in 1939:

It is possible that some of the glauconitic sand of the Woolwich Beds became admixed, by gentle erosion in shallow water, with the shelly top of the Thanet Beds below.

Road-widening in 1939 for about 100 m farther east [TR 045 609] continued the section nearly to the top of the Woolwich Beds, the details being:

With the sands noted previously the total section is about 8 m of Weolwich Beds. Along the main coastal road which is joined just to the east, coarse-grained orange and grey speckled sand with ironstone was poorly exposed for about 1 m depth, while at the place [TR 050 610] where this road crosses on to the Thanet Beds the basal Woolwich Beds clayey sand was noticed.

A small outlier of the clayey sands with ironstone appears to cap the rise a little east of Homestall, and another, somewhat larger mass is mapped south-south-west of Fairbrook Farm. The occurrence of Woolwich Beds in these areas eastward and southward of Goodnestone appears to mark a limited region of local southward transgression on to the Thanet Beds, of which, to judge from well-records and from the outcrops, probably little more than about 18 to 21 m are present on the south. The section described above along the Faversham road affords support to this view, for the Woolwich Beds deposits rest on a shell bed (see p.28) believed to be the condensed equivalent of a bed known on the coast to be 3 to 5 m below the top of the Thanet Beds.

East of Fairbrook Farm the deep valley with branches on its eastern side separates the sinuous main outcrop of Woolwich Beds in the Hernhill district, where the beds are practically free of drift and well exposed in a number of sections until they follow the Alluvium to join the outcrop previously described, near Graveney. The high ground 0.8 km SW of Hernhill has a very thin capping of Woolwich Beds which appears in road banks as a coarse-grained brightly orange-weathered clayey sand or somewhat finer-grained glauconitic sand with ironstone. SCAH

The section [TR 064 606] in the sand-pit (Plate 3) 100 m SW of Hernhill church was as follows:

The cutting at the entrance to the pit exposed, beneath coarse-grained glauconitic sand, a distinctive group of basal Woolwich Beds consisting of:

Whitaker (1872, p. 165) observed in the adjoining lane, southward of the church, a mauve-grey sand just below the Oldhaven Beds and basal coarse-grained cross-bedded ferruginous sand above the Thanet Beds. He also saw the mauve-grey sand beneath the Oldhaven Beds in the lane a little north of the church. In 1938 a section [TR 066 607] 140 m NE of the church was seen in a small cutting where, beneath weathered fragments of hard mauve-grey sandstone was 2 m of coarse-grained quartzose glauconitic sand with a loamy bed, 0.15 m thick, in the middle. Coarse-grained sand caps the long spur of high ground west of Hernhill.

A large sand-pit [TR 063 614] 0.4 km W of Fostall showed a good section of Oldhaven Beds and Woolwich Beds (Plate 4). The section at the southern end was:

Northwards the topmost 1.5 m of sands become mauve at the top and at the bottom, with hard sandy concretions; but at the northern end of the section 0.6 m of grey and yellow sand separates sand with hard mauve-grey concretions from the fine-grained sands of the Oldhaven Beds. Whitaker (1872, p. 164) saw a section in this pit and quotes Hughes' notes of sand with a few pebbles, probably marking the base of the Woolwich Beds, seen in the road nearby. Whitaker also saw coarse-grained Woolwich Beds sand beneath the Oldhaven Beds in the lane towards Fostall from the hill on the south and similar sand occurs in the lane north-east of Fostall. The hard mauve sand also crops out at the former place. Another section seen by Whitaker was at the farm nearly 0.8 km SSW of Dargate House, where the coarse-grained sands appeared beneath Oldhaven Beds in a small pit. A narrow tongue of Woolwich Beds crops out in a shallow valley as far as this location, and there is an inlier of Woolwich Beds, with coarse-grained sands, free of drift only on the west, in the low-lying tract about Dargate Common. SCAH, JRE

Along the main coastal road, coarse-grained pale-grey glauconitic sand occurs west of Dargate House and the road cutting at a point [TR 069 619] 600 m W of the House showed the typical hard mauve sand near the top of the Woolwich Beds cropping out some 0.9 m below the Oldhaven pebble bed. In the road-cutting [TR 062 616] 0.4 km WNW of Fostall however, the mauve sand appears to be absent and to be replaced by the usual coarse-grained Woolwich sand. The road section [TR 060 613] 0.2 km S of Waystreet Farm exposed 0.6 to 0.9 m of sharp brown sand with a concretionary ironstone band overlying sands of the Thanet Beds (p. 28). Approximately at this locality was a former section from which Prestwich (1852, p. 246; 1854, p. 109) obtained many silicified shells, including Corbula regulbiensis in abundance. This is considered to be a shelly development of the band with concretionary ironstone noted above. Whitaker (1872, pp. 87, 575) placed the bed in the Thanet Beds and correlated it with the shelly bed previously noted at Goodnestone (p. 28); but Corbula was found only in the bed seen by Prestwich and results of the 6-inch survey indicate continuity with the bed taken as the base of the Woolwich series, where, indeed, Prestwich finally placed it. Correlation with the Corbula bed of the coast section is strongly suggested.

The lane 275 m NW of Waystreet Farm [TR 058 618] exposed the basal bed as a coarse-grained greenish glauconitic sand with small iron-rich concretions. At Waterham a pit [TR 069 622] 320 m SE of the summit of Horse Hill exposed the Oldhaven pebble bed (p.40) and beneath it the top Woolwich Beds as follows:

West of Horse Hill the Woolwich Beds sands fall to Alluvium level but rise again near Graveney and emerge from beneath Alluvium and Head Brickearth to form the outcrops already described.

In the valley of the Great Stour the Woolwich Beds crop out as a narrow belt following the embayed hillside until the dip carries the beds below the drift beyond Westbere. Good exposures are to be found in sand-pits and where patches of overlying brickearths and gravels have been worked.

Near Sturry [TR 162 602] the large pit about 0.5 km S of Shelford Farm has long exposed London Clay, Oldhaven Beds and Woolwich Beds. The excellent section seen in 1946 was:

Borings in the floor of the pit passed through a clayey bed, probably the base of the Woolwich Beds and practically reached in the above section; a later borehole (Gamble, 1972, p.475) confirmed the associated pebbly facies. SCAR

In 1976, some 10 m of Woolwich Beds were exposed. These beds appeared structureless in the top 2 m, weakly cross-stratified from 2 to 5 m and intensely bioturbated below. A shaly grey clay was present locally in the basal 2 m. RAE

The tubular 'almost segmented' nodules described by Smart (in Smart and others, 1966, pp. 179, 193) are those now referred to the burrows (Ophiomorpha nodosa) of a callianassid crustacean (Kennedy and Sellwood, 1970; Gamble, 1970, pp. 397–398). Their shapes are strikingly picked out by differential weathering, particularly in the lower beds. Carstone development also extends along joints and bedding planes, producing anastomosing complex overall patterns. Mr Smart noted a thin seam of clay occurring locally just below the top of the Woolwich Beds. Gamble (1968, pp. 587–589; 1972, pp. 474–475) has made valuable detailed records of this famous section.

A disused pit [TR 167 604] about 0.5 km ENE of the last, on the west side of the road to Broadoak, exposed 6 m of Woolwich Beds:

Dewey (in Dewey and others, 1925, p.286) noted this section and the cylindrical bodies contained in the Woolwich Beds; these are tubular, carstone-lined, Ophiomorpha burrows.

Northward of Sturry much of the Woolwich Beds has been scoured out by river action and replaced by River Gravel deposits. Beneath the gravels (see p.74) in the pits [TR 176 606] 0.4 km NW of Sturry Station 0.9 m of speckled ferruginous sand was seen on the north-east and the glauconitic basal bed with ironstone and small pebbles on the south-east. Opposite these pits and on the eastern side of the Herne Bay road Whitaker (1872, p. 168) saw, beneath gravel, a section of coarse-grained ferruginous sand with a few pebbles, but in 1946 the only sections visible were in old gravel pits about 320 m NNE [TR 179 607] and 550 m NE [TR 181 608] of the station. The first of these showed 1.1 m of cross-bedded coarse-grained speckled sand with variable ironstone and very occasional small pebbles at the base; in the second only 0.3 m of sand with a clay seam, ironstone and rare very small black pebbles was seen beneath the drift and overlying the Thanet Beds. The large old pit [TR 185 611] 1 km NE of the Station exposed Woolwich Beds in a number of places. The main face showed, beneath the Oldhaven Beds (see p.41), about 3 m of coarse-grained speckled sand with brownish loamy seams and patches, passing down into 3 m of similar sand with grey, green, yellow and brown beds and irregular ironstone increasing downwards; at the top of the latter sand a seam of white clay-silt occurs. The junction with the Thanet Beds was seen in the narrow southern part of the pit, beneath River Gravels, the basal Woolwich Beds consisting of about 1.5 m of cross-bedded grey and green coarse sand with thin silty partings. Ironstone is weakly developed, but impersistent clayey seams and a few small black pebbles occur at the base, which showed an irregular festooned junction with the underlying Thanet sands (p. 28). About 140 m NE of the road-fork eastward of this pit a small pit [TR 186 610] on the north-west side of the main road showed 1.8 m of coarse-grained speckled sand beneath River Gravel (p. 76).

Near Westbere a number of small pits exposed the Woolwich Beds and the first four sections to be described below also appear in Whitaker's account (1872, p. 168). The pit [TR 191 611] 180 m W of the church showed only overgrown coarse-grained speckled sand reaching to the Oldhaven Beds at the top of the bank, and another [TR 192 612], 100 m NNW of the church was also mainly overgrown but showed the junction of 0.9 m of pale speckled ferruginous sand with the Oldhaven Beds above. In the pit [TR 193 611] 140 m ENE of the church the rather degraded section was:

The division from the Thanet Beds was clearer than is suggested by Whitaker's description. About 320 m ENE of the church, in a series of three old pits [TR 196 612] east of the road ascending the hill at the east end of the village, coarse-grained grey sand of the Woolwich Beds was exposed in the middle one, and Whitaker saw a section in the lower one (now obscured) showing Woolwich Beds sand with large dark grains overlying finer-grained sand referable to the Thanet Beds. A disused pit [TR 192 613] 230 m N of the church showed about 3 m of pale speckled sand with coarse-grained ferruginous sand below and 100 m NE of this section 2.4 m of coarse-grained dark sand with lighter streaks was seen, just below the Oldhaven Beds in a small pit [TR 193 614]. The coarse-grained sand was also seen at the bottom of old gravel pits [TR 194 612] on the hill 230 m ENE of the church.

On the opposite side of the Great Stour valley, Woolwich Beds and gravel cap the hill west-south-west of Stodmarsh. Pits [TR 215 603] were seen at the eastern end of the ridge, about 0.5 km WSW of Stodmarsh church, and Whitaker (1872, p. 172) saw a section here ('south of Stodmarsh Court') which gave the junction with the underlying Thanet Beds: greenish grey sand with small pebbles at the bottom marking the Woolwich base. In 1946 this section was obscured but westward an extension of the working for gravel had exposed the typical coarse-grained ferruginous sand to a depth of 1.2 m beneath the drift. Gravel was extensively dug along this ridge after 1951 and the excavations have shown that in fact very little Woolwich Beds sand has remained uneroded farther south-west beneath the drift, which for the most part rests upon Thanet Beds.

Across a small tributary valley Woolwich Beds are again present at Grove Hill and the dip carries them down to Grove. Brickearth and gravel cover the sands, however, and they were only exposed in the old gravel pit [TR 227 604] at the road-fork 0.4 km SSW of Grove Hill. In 1.2 m of coarse-grained sand beneath the drift a ferruginous bed was noted at the top and small pebbles at the junction with the Thanet Beds below.

On the east bank of the Little Stour the Woolwich Beds near Preston appear in places where drift is absent and probably join beneath the Alluvium with those of Grove. At the southern border of the Faversham (273) Sheet the coarser-grained sands of the Woolwich Beds, with small pebbles at the base, present a fairly clear distinction from the Thanet Beds. Coarse-grained yellow and brown sand was seen beneath the drift in the old gravel pits [TR 243 605] adjoining Preston Court on the west, and an old pit [TR 245 607] in a wood 230 m NNE of Preston Court showed the junction of 3.7 m of glauconitic brown and yellow Woolwich Beds sands with the overlying Oldhaven Beds (p.42). The large gravel workings [TR 247 614], now disused, 0.5 km north-by-west of Preston Street have cut down to coarse-grained dark green sand of the Woolwich Beds below the River Gravels (see p. 77).

The Woolwich Beds at Elmstone, the village 1.2 km SE of Preston, are overlain by brickearth except for a tract on the south and east sides of the small valley. The base is marked by the characteristic coarse-grained orange-weathered clayey glauconitic sand with small pebbles, and a section was formerly visible (Whitaker, 1872, p.173) in an old pit [TR 261 602], 100 m S of the church, which also exposed sand referred to the Thanet Beds (see p. 29).

The outcrop near West Stourmouth is entirely covered by brickearth, but a little to the east of the Faversham (273) Sheet a well at Stourmouth House (East Stourmouth) proved 7.6 m of Woolwich Beds, consisting of greenish sands with iron-sandstone at the top and a bed of small pebbles at the base.

North of the Great Stour the Woolwich Beds crop out from Grove Ferry through Chislet and past Herne and Highstead to the coast at Reculver, and are only locally covered by drift. Whitaker (1872, p. 168) saw a clear section in the railway cutting just west of Grove Ferry Station. He also described (p. 169) a section in Oldhaven Beds and Woolwich Beds seen in the road cutting, north of Millbank, 'on the road from Maypole Street to Hoathborough', and a further section in these beds, evidently disturbed, in a pit lower down the hill on the western side of the road. A pit [TR 202 654] 0.2 km NW of Millbank showed 1.2 m of medium-grained grey sand speckled with glauconite beneath the Oldhaven pebble bed (see p.43), but Whitaker appears to have seen 6 m of the Woolwich Beds sand here. The road cutting on the north side of Ford (formerly Hoathborough) is partly in brickearth and gravel but also cuts down into Woolwich Beds and Thanet Beds. Whitaker was able to make out Woolwich Beds sands with the highest part rather clayey and iron-stained but his record of sand with pebbles and subangular flints must refer to the overlying drift. The sand-pit [TR 204 659] 230 m NW of Ford Manor House exposed in 1938 drift and medium-grained grey sand of the Woolwich Beds up to 3.7 m thick, overlying the Thanet Beds (see p. 29). The base of the Woolwich series is marked by lenses of coarse-grained glauconitic sand with Corbula. In the bottom of the valley to the west the basal Woolwich Beds tend to give rise to marshy ground and are probably somewhat clayey, a feature which appears to be lost however, on approaching the coast. In 1938 soft medium- to coarse-grained Woolwich Beds sands were visible beneath the Oldhaven Beds (p.43) in a pit [TR 190 660] just south of Hawe Farm.

At Herne, the head of the valley is occupied by Oldhaven Beds but there is no inlier of Woolwich Beds as shown on the Old Series map. Whitaker (1872, p. 171) described a temporary section about 0.4 km NNW of the church showing clay with pebbles on greenish grey sand; there is now no doubt, however, that these beds include the basement bed of the London Clay.

A section [TR 225 677] on the coastal road just west of the Roman Galley inn, east of Hillborough, showed the Oldhaven pebble bed resting on 2.7 m of Woolwich Beds sands, coarse-grained and glauconitic at the top, pale buff in the middle and ferruginous below. The western part [TR 219 679] of the railway cutting near Brook Farm, southward of Reculver, again clearly exposed coarse-grained glauconitic Woolwich Beds sands beneath the Oldhaven pebble bed. Whitaker (1872, p.90) appears to have mistaken much of the finer-grained Oldhaven sands for Woolwich Beds in the section as he saw it, though he recognised the divisions in the road cutting north-east of Hillborough (at that time known as Reculver). SCAH

The Woolwich Beds of the coast section are exposed no less clearly than the Thanet Beds and a greater advantage is that their full thickness of some 7.5 m may be observed. Of early full descriptions the more important are by Prestwich (1854, p. 110), Dowker (1864, p. 342), Whitaker (1872, p.170) and Gardner (1883, p.205). In 1938 the cliff 550 m westward [TR 222 692] of the ruined church at Reculver exposed 0.6 m of brickearth, 2.7 m of pale grey sand and 0.5 m of ferruginous sand with coarse-grained glauconitic lenses and Corbula, overlying the Thanet Beds (p.29). Just over 0.8 km beyond this point the section [TR 214 690] beneath the London Clay and Oldhaven Beds p. 44) was as follows:

At that time the line of division from the Thanet Beds was not distinct here. The following is a generalised section of the Woolwich Beds as seen 2 km westward of Reculver:

Dr S. Buchan has pointed out that the lower half of the 0.6 m clayey bed with pebbles and pyrite in the above section corresponds to the 'Woolwich Bottom Bed' of Gurr (1963, p. 420) subsequently seen (in 1959 and 1960) on the foreshore between 240 and 330 m westward of Bishopstone Gap (see p. 31). When Stinton (1965, p. 176) saw the bed at Bishopstone or Oldhaven Gap in 1964 it there consisted of only 'a single line of small pebbles with occasional decorticated sharks' teeth', and by 1966 (Gamble, 1968, p. 591) it had disappeared completely: the Corbula regulbiensis Bed, however, some 1.8 m lower down, was still visible as 'a series of small "nests" of this bivalve occurring regularly along the same horizon'. It is apparent that in detail the distinction of the Woolwich Beds from the much less variable sands of the Thanet Beds is lithologically maintained in the coastal section (cf. Whitaker, 1912, p.248), though the sands are not so coarse as inland and the actual basal bed both lacks its usual pebbles and when unweathered is not so strikingly clayey and coarsely glauconitic as in many inland sections. Dewey and Brown (in Dewey and others, 1925, p.285) and Pitcher (in Pitcher and others, 1967, p. 28) have also drawn attention to the characteristically local developments of the silicified Corbula Bed at the coast, with intervening patches of crumbling ferruginous casts only; Brown (1936, p. 350) mentioned plentiful 'nests' of Corbula, etc., exposed by erosion of the cliffs. These observations, however, may refer to any of a range of sands containing Corbula, down to some 6 m in the Thanet Beds. The bed of concentrated Corbula nevertheless provides a recognisable dividing line from the Thanet Beds that on regional grounds is stratigraphically preferable either to an arbitrary boundary taken at a lower level or to a local one 1.8 m higher up, even though it is here lithologically distinct and on the foreshore weathered out sharply (on account of a local Ophiomorpha band above it).

The coast section in fact happens to lie where the pebble-bed taken in this memoir to mark the base of the Woolwich Beds is commonly very difficult to recognise, and the local sequence is varied. This has led workers of the Tertiary Research Group (Ward, 1978) to accept Gurr's bed with fish remains and a line of pebbles as the defined base of the Woolwich Beds. The section as seen in June 1974 showed a new reappearance of this lenticular band, when Dr W. A. Read reported that the contact with the sands below was very diffuse, the bed greatly disturbed by burrows and the tiny pebbles exceedingly rare. Mr J. Cooper and Mr D. J. Ward demonstrated their reasons for defining the 'Woolwich Basal Pebble Bed' as this 0.23 m-thick bed, however, and also their usage (cf. Hester, 1965) of the term 'Woolwich Bottom Bed (Woolwich Sands Member)' for the 4.6 m or so of unfossiliferous sands above, which extend to the top of the formation (see Ward, 1978).

By September 1975 (see also p. 108) the amount of weathering in situ that had resulted from artificial stabilisation of the foreshore had served to pick out clearly in the cliff a rusty glauconitic band about 0.3 m thick, densely crowded with silicified Corbula, that bore a striking resemblance to its inland counterpart taken as the base of the Woolwich Beds throughout the Faversham and the Canterbury areas. SCAH

References

BRITISH MUSEUM (NATURAL HISTORY). 1968. British Caenozoic fossils. [3rd Edition] (London.)

BLONDEAU, A. and POMEROL, CH. 1969. A contribution to the Sedimentological study of the Palaeogene of England. Proc. Geol. Assoc., Vol. 79 [for 1968], pp. 441–455.

BROWN, E. E. S. 1936. Field meeting at Herne Bay and Reculver. Proc. Geol. Assoc., Vol. 47, pp. 349–351.

COLLINS, I. and GILL, D. M. C. 1923. Notes on the geology of Boughton-under-Blean, with Report of Excursion. Proc. Geol. Assoc., Vol. 34, pp. 300–313.

COOPER, J. E. 1934. Oldhaven and Thanet Sand Mollusca of Herne Bay. J. Conch., Vol.20, No.1, pp.4–8.

COOPER, J. 1976. British Tertiary stratigraphical and rock terms, formal and informal, addition to Curry 1958. Lexique Stratigr. Int. Spec. Pap. Tertiary Research, No. 1.

CURRY, D. 1958. Lexique Stratigraphique International, Vol. 1, Part 3a XII: Great Britain-Palaeogene.

CURRY, D. 1965. The Palaeogene Beds of South-East England. Proc. Geol. Assoc., Vol. 76, pp. 151–173.

CURRY, D.1966. Problems of correlation in the Anglo-Paris-Belgian Basin. Proc. Geol. Assoc., Vol. 77, pp. 437–469.

DEWEY, H., WOOLDRIDGE, S. W., CORNES, H. W. and BROWN, E. E. S. 1925. The Geology of the Canterbury district and Report of Excursion. Proc. Geol. Assoc., Vol. 36, pp.257–290.

DOWKER, G. 1864. Excursion to Herne Bay and Reculver. Proc. Geol. Assoc., Vol. 1, pp. 339–344.

GAMBLE, H. J. 1968. Field Meeting to East Kent. Proc. Geol. Assoc., Vol. 78 [for 1967], pp. 587–593.

GAMBLE, H. J. 1970. Discussion on Kennedy and Sellwood 1970. Proc. Geol. Assoc., Vol.81, pp. 397–398.

GAMBLE, H. J. 1972. Field meeting to Boughton and Canterbury, Kent. Proc. Geol. Assoc., Vol.83, pp. 471–478.

GARDNER, J. S. 1883. On the Lower Eocene section between Reculvers and Herne Bay, and on some modifications in the classification of the Lower London Tertiaries. Q. J. Geol. Soc. London, Vol. 39, pp. 197–210.

GURR, P. R. 1963. A new fish fauna from the Woolwich Bottom Bed (Sparnacian) of Herne Bay, Kent. Proc. Geol. Assoc., Vol. 73 [for 1962], pp. 419–447.

HAYNES, J. 1956. Certain smaller British Paleocene foraminifera, Part I. Contrib. Cushman Found. Foram. Res., Vol. 7, Part 3, pp. 79–101.

HAYNES, J. 1958. Part V. Distribution. Contrib. Cushman Found. Foram. Res., Vol.9, Part 4, pp. 83–92.

HAYNES, J. and EL-NAGGAR, Z. R. M. 1964. Reworked Upper Cretaceous and Danian planktonic foraminifera in the type Thanetian. Micropalaeontology, Vol. 10, No. 3, pp. 354–356.

HESTER, S. W. 1965. Stratigraphy and palaeogeography of the Woolwich and Reading Beds. Bull. Geol. Surv. G.B., No. 23, pp.117–137.

KENNEDY, W. J. and SELLWOOD, B. W. 1970. Ophiomorpha nodosa Lundgren, a marine indicator from the Sparnacian of South-East England. Proc. Geol. Assoc., Vol.81, pp. 99–110.

PITCHER, W. S. 1967. Geologists' Association Guides, No. 30B: The London Region (South of the Thames). North Kent Coast-Herne Bay, pp. 26–28.

PRESTWICH, J. 1852. On the structure of the strata between the London Clay and the Chalk in the London and Hampshire Tertiary Systems. Part III-The Thanet Sands. Q. J. Geol. Soc. London, Vol. 8, pp. 235–268.

PRESTWICH, J. 1854. Part II-The Woolwich and Reading Series. Q. J. Geol. Soc. London, V ol. 10, pp. 75–170.

SCHIMPER, W. P. 1874. Traite de paleontologie vegetale. Vol.3,896 pp. with an atlas of 110 pls. (Paris.)

SMART, J. G. O., BISSON, G. and WORSSAM, B. C. 1966. Geology of the country around Canterbury and Folkestone. Mem. Geol. Surv. G.B.

STINTON, F. C. 1965. Field meeting in the Lower London Tertiaries of Kent. Proc. Geol. Assoc., Vol. 76, pp. 175–177. WARD, D. J. 1978. The Lower London Tertiary (Palaeocene) succession of Herne Bay, Kent. Rep. Inst. Geol. Sci., No.78/10.

WHITAKER, W. 1866. On the 'Lower London Tertiaries' of Kent. Q. J. Geol. Soc. London, Vol. 22, pp. 404–435.

WHITAKER, W. 1872. The geology of the London Basin. Mem. Geol. Surv. G.B.

WHITAKER, W. 1912. Report of an excursion to Reculvers. Proc. Geol. Assoc., Vol.23, pp. 247–249.

WHITAKER, W. and DOWKER, G. 1885. Excursion to Canterbury, Reculvers, Pegwell Bay and Richborough. Proc. Geol. Assoc., Vol. 9, pp. 168–177.

WHITE, E. I. 1931. The vertebrate faunas of the English Eocene, 1. From the Thanet Sands to the Basement Bed of the London Clay. (London: British Museum (Natural History.) )

WHITE, H. J. O. 1928. The geology of the country near Ramsgate and Dover. Mem. Geol. Surv. G.B.

WRIGLEY, A. 1949. The Thanet Sands. South-eastern Naturalist, Vol. 54, pp. 41–46.

Chapter 6 Tertiary (Continued)

Oldhaven Beds

The mass of London Clay comprising Sheppey and the Blean is underlain by a bed of sand with pebbles, the outcrop of which follows closely the London Clay base and which is known as the Oldhaven Beds. There are a few small outliers in the Faversham district but the only fairly wide spreads are found around Hernhill and southward of Reculver. Nowhere do the beds much exceed a thickness of 6 m, which is also their average. Near Oare, where the beds appear to be abnormally thin, their outcrop is exceedingly narrow (see p. 40); northward of Faversham generally, borehole records indicate thicknesses of only 2.4 to 4.0 m at localities north of Oare, at the south side of Harty Ferry, east of the Isle of Harty and at Graveney Marshes. This local thinning, however, contrasts with a stronger development of the beds about Hernhill and at Goodnestone, where a very pebbly type persists southward, probably with a transgressive base.

Prestwich (1850, p. 265; 1854, p. 111) grouped the series as Basement-bed of the London Clay without, however, implying that the beds were part of that formation; in this he was followed by Dowker (1864, p. 342). Whitaker (1862, p. 267; 1864, p. 60) was inclined to place the beds with the Woolwich Formation but later showed that they have a separate identity (1866, p. 412; see also 1872, p. 239). The name he took from Oldhaven Gap, west of Reculver, a locality known today as Bishopstone Glen. Gardner (1883, p. 207) recognised that the Oldhaven Beds are linked palaeontologically with the London Clay and regarded the physical break indicated by pebble beds at their base as the only significant one in the Lower Eocene (as then termed) in East Kent (cf. Leighton, 1894, p. 376). Collins and Gill (1923, pp. 307, 309) accepted the basal pebble bed as the natural line dividing the Oldhaven Beds from the Woolwich Beds for all practical purposes but they wished to regard the lilac sandstone horizon a metre or so down in the Woolwich Beds sands as marking theoretically the commencement of the Ypresian (Oldhaven Beds and London Clay) cycle of marine transgression. These authors record pebbles of the lilac sandstone higher in the Woolwich Beds sands below the Oldhaven pebble bed, in a pit at the east end of Boughton-under-Blean, south of the Faversham (273) Sheet, a feature which appears to denote erosion soon following consolidation in shallow water conditions near the end of Landenian (Woolwich) times. The common occurrence of derived pebbles, blocks and boulders of the material, as well as of somewhat similar derived ironstone, in the Oldhaven pebble beds, however, offers good grounds for retaining the base of the pebble bed as a boundary appropriate from both points of view. Stamp (1921, p. 100) was early to point out that the marine fauna, as opposed to its estuarine equivalents elsewhere, is allied to that of the London Clay, that the beds have an unconformable base which may cut down into the sands below and that though they should in practice retain their entity and independent position, 'from a physical and stratigraphical, as well as from a palaeontological point of view, they mark the opening phase of the Ypresian (London Clay) and should be grouped with that period'.

Above the basal bed of black flint pebbles, which is sometimes associated with fairly coarse-grained sand, the sands are fine in grade and frequently a uniform golden brown in colour, except where ironshot. Ironstone is commonly developed at and near the base, as well as at higher levels, and thin clay seams in the upper parts have all the appearance of London Clay, foreshadowing the conditions which later became dominant. The sands are quite frequently shelly, especially where locally cemented into soft sandstone beds. Southward of Goodnestone the pebble bed appears to dominate and to cut down deeply through the Woolwich Beds, perhaps even to their base. This suggests a local shoreline facies which may be comparable with the shoals of black pebbles in a sandy matrix which have been described farther south on the Canterbury (289) Sheet, at Selling (Whitaker, 1872, pp. 162, 271; Collins and Gill, 1923, p. 311; Wooldridge in Dewey and others, 1925, p. 270; Smart and others, 1966, p. 194). The further work has shown, however, that neither the pebble bed nor the 'Blean ironstone' frequently associated with it (see Whitaker, 1872, pp. 240, 268, etc.) exhibits the general thinning northward implied by Collins and Gill (1923, p. 308). On the contrary there appear to be local quite abrupt lateral changes in the lower half of the Oldhaven Beds. Other instances of local dominance of pebbles are from well records at Upstreet and at Graveney Marshes. The presence in the pebble bed of lilac sandstone blocks derived from the top Woolwich Beds appear to be confined to the area west of the Blean and to the neighbourhood of Sturry. This is also indicative of shallowing sea or perhaps even land to the south-west, where this sandstone occurs in situ. The pebble bed in the eastern part of the area, however, similarly sometimes contains ironstone which appears also to have been derived from a bed in the Woolwich series of that general region. The derived ironstone occurs both at Sturry and north and eastward beyond the known occurrence of the lilac sandstone boulders.

The conditions of deposition of the Oldhaven Beds, their affinity with the predominantly pebbly facies known as the Blackheath Beds and their relationship to the Woolwich and Reading Beds have been dealt with thoroughly by Stamp (1921, pp. 68, 71, 99). After a shallow lagoonal phase represented by the top beds of the Woolwich Formation, the invading sea, with varying and powerful currents considerably disturbed the soft Woolwich strata especially where subaqueous shingle banks were being formed. With the deepening of the sea quieter conditions obtained and there was only a slight interruption of normal sedimentation at the oncoming of London Clay deposition. The latter type was foreshadowed in the Oldhaven Beds where the thin clays occur. Prestwich (1850, p. 277) records that green-coated flints derived from the base of the Thanet Beds are present in the pebble bed at Herne Bay, and Whitaker (1866, p. 419) has emphasised that denudation in Oldhaven times must have extended in places to the Chalk. Stamp (1921, p. 70) noted that most observers (Whitaker, 1866, p. 415; 1872, p. 240; Young, 1910, p. 257) had agreed that the characters of the pebbles are such as to preclude the notion of beach or subaerial origin (Gardner, 1883, p. 209). The perfect rounding and absence of cortex or bleaching point rather to 'continued movement in submarine shoals some distance from land'.

In east Kent the Oldhaven Beds are wholly marine and therefore carry throughout them (with decreasing frequency upwards) the burrows of Ophiomorpha nodosa (see p.31) that are to be found at Shelford (p. 41) and Bishopstone (p. 44); these burrows are also very strongly developed in the Woolwich Beds and occur in the Thanet Beds and occasionally within the London Clay Basement Bed (Gamble, 1970, pp. 397–398). Mr Gamble states that both lined and unlined burrows characterise the Oldhaven Pebble Bed, where they are in sandy lenticles and partings.

The Oldhaven Beds of the district as a whole are summarised in the following general succession:

Details

The beds are beneath drift where they enter the district on the north of Luddenham Marshes, but a very small outcrop of fine-grained yellow and buff-grey sand occurs [TQ 985 651] at the extreme western edge of the London Clay spur bounding the marshes on the north-east.

At Howletts fine-grained sands flank the marsh and southward of Uplees the outcrop first includes a number of small islands in the Alluvium and then passes on to solid ground entirely.

Towards Oare the outcrop appears to become very narrow but the beds are largely obscured by brickearth and gravels which were formerly unevenly dug over. Two small outliers occur about 0.5 km NW and a similar distance west of Oare, each consisting of rather fine-grained orange and brown sand and loam capped by London Clay. Black pebbles were noted in the Oldhaven Beds of the southern outlier.

The steep bank bordering the alluvium on the north-west side of the creek at Oare is obscured by downwash from the London Clay, and the Oldhaven Beds are not seen again until they emerge from beneath the Alluvium near Nagden. The sand is mainly fine-grained, sometimes loamy, and pebbles are found in the soil locally. It forms a continuous outcrop around the London Clay outlier on the hill east of Sandbanks, just east of which place 1.1 m of fine-grained golden sand were seen beneath the London Clay (p. 48) in a temporary excavation [TR 040 626]. South of the road junction and about 0.4 km SSW of Broom Street there is, however, a small pebbly outlier.

Near Broom Street and Graveney the beds are mainly beneath Alluvium and Head Brickearth but fine-grained sands with some glauconite occur on the rising ground about Graveney church and 0.4 km to the south-west. Fine-grained sand with the pebble bed caps the ridge east of the road to Goodnestone, and a number of very small pebbly outliers southward of this seem to suggest that the Oldhaven Beds hereabouts are transgressive and cut down, probably irregularly, into the underlying Woolwich Beds. When the two southernmost outliers are considered in relation to two well records at these places, further support is lent for this explanation. At the outlier on the south-east side of the main road the Woolwich Beds may be almost entirely cut out. SCAH

Fine-grained golden sand was seen beneath the London Clay in the railway cutting [TR 061 630] 0.8 km ENE of Graveney church (Whitaker, 1872, p.266) and in the road cutting [TR 060 628] 180 m SSW of this. The narrow outcrop expands eastwards near Water-ham, and the pit [TR 069 622] 320 m SE of the summit of Horse Hill exposed the Oldhaven pebble bed, coarse-grained pale grey sand with numerous black flint pebbles, capping the Woolwich Beds (p. 34). In the middle of the northern face the pebble bed was seen to divide into a 0.10-m and a 0.18-m bed with a 0.10-m layer of coarse-grained grey sand between.

Around Dargate House the pebble bed appears to be overlain by a yellowish brown concretionary ironstone, seen loose in the orchards and fields, particularly west and north of the house. The main coastal road on the north-west cuts through the pebble bed and the latter was exposed [TR 069 619] on the south side at a point some 600 m W of Dargate House. The road also cuts a small outlier of fine-grained yellow sand about 0.4 km WNW of Fostall, but the beds are much more pebbly where they cap the hill, together with stony drift, just south-west of Waystreet Farm.

In the Dargate–Fostall–Hernhill area the sand is present over most of the outcrop. The sand-pit [TR 063 614] 0.4 km W of Fostall (Plate 4) showed 1.8 to 2.4 m of Oldhaven Beds overlying the Woolwich Beds (see p.33). The fine-grained yellow sands contain loamy layers and thin clay bands and a glauconitic bed with fish teeth was noted 0.76 to 0.91 m above the basal pebble bed. The latter is variable in strength in different parts of the pit but its thinning out is purely local and there is not the complete absence of the pebble bed which Collins and Gill (1923, p. 313) thought to be significant. In the lane towards Fostall from the hill on the south Whitaker (1872, p. 164) noted in the midst of Oldhaven sand nearly 0.6 m of brown laminated clay with ironstone in its middle part. On the bend of the road [TR 066 612] south-west towards Hernhill fine-grained Oldhaven Beds sand underlies the London Clay.

Whitaker also saw a section in a small pit at the farm nearly 0.8 km SSW of Dargate House, where small black pebbles and lumps of concretionary sandstone derived from the top beds of the Woolwich series were seen by him to mark the junction of the Oldhaven Beds fine-grained buff sand and loam with the underlying coarse-grained Woolwich Beds sands. In a further section at Dargate, on the southern side of the road, nearly 0.8 km SSE of Dargate House Whitaker (1872, p. 266) described 6 m of light buff sand, with a few layers of fossils, and containing more dark grains below the middle; a green bed with fish teeth, etc. and rare flint pebbles he noted 2.1 m from the bottom; 0.3 m below there were locally more teeth and below this the sand appeared coarser-grained and firmer. London Clay caps this old pit [TR 0790 6135] and almost the whole of the Oldhaven Beds was probably represented in the section. Whitaker also saw another pit, on the north side of the road, which exposed an irregular bed of ferruginous clay and ironstone in the sand. Fine-grained golden sand underlain by concretionary ironstone occurs 0.4 km SW of Dargate House, on the east side of a small valley. Numerous loose pebbles derive from the horizon immediately below the ironstone.

Around Hernhill a number of small exposures have been recorded. In the lane a little north of the church Whitaker (1872, p. 165) saw light grey and buff sand with a few small black flint pebbles at the bottom, resting on the Woolwich Beds. Down the hill just southward of the church, however, he noted that the basal Oldhaven Beds were represented by ironshot sands with a bed of fragmentary ironstone and appeared to dip northward into the hill at an angle up to 10°, unconformably, however, to the sands below. Such irregularities at the base of the series are locally not uncommon depositional features. Fine-grained golden sand was seen underlying the London Clay in the roadside [TR 071 606] 600 m ESE of Hernhill church and in a steep bank [TR 071 602], south of the farm, 800 m SE of the church. SCAH, JBE

The outcrop of the Oldhaven Beds along the steep left bank of the Great Stour valley is extremely narrow, and indeed where gravels of the Third Terrace occupy an erosional bench in the hillside near Sturry the beds appear to have been cut right back in vertical face to their position of emergence from under the London Clay, so that they appear on the map discontinuous beneath the drift.

West of Sturry, the Oldhaven Beds in the large pit [TR 162 602] about 0.5 km S of Shelford Farm were well exposed in 1946 and in 1951. About 5.2 m of sands are overlain by London Clay (p.49) and underlain by Woolwich Beds (p. 35). The following is a typical section, but there are also important variations:

The pebble bed, the line of which is diversified by small-scale trough faulting, shows strikingly in a fresh sand face. In 1951 the beds on the north were seen in more detail. First the clayey brown sand gave place to about 1.6 m of massive iron-sandstone, partly concretionary, and with clusters of pebbles in hollows at the base and between the concretions; farther north nodular ironstone was developed irregularly on a smaller scale; beyond this the basal beds were as follows:

The sandstone boulders are derived from the Woolwich Beds, evidently mainly from the west, in which direction only is the bed known to occur in situ. As described by Smart (in Smart and others, 1966, p. 197) the pit when extended about 1953 had shown 5.2 to 6.9 m of Oldhaven Beds, the basal bed of which included not only the purple sandstone blocks but also 'large masses of bored ironstone enveloped by pebbles, sands and clays in places'. The section as seen in 1965–66 is given in some detail by Gamble (1968, p. 589), together with (p. 591) a list of mollusca and sharks, the teeth of which were found with selachian vertebrae and portions of turtle scute; the mollusca occur typically in soft cementstone bands, the sands and silty lenticles contain well-formed selenite 'sand-roses'. In 1971 the large and impressive section was again visited by the Geologists' Association (Gamble, 1972, pp. 475–476) when Mr Gamble drew further attention to the Oldhaven Pebble Bed and its erosional implications; the numerous rolled and bored remanie blocks of purple, pink or grey fine-grained sandstone and occasional carstone pebbles he considered not to have travelled far from their sources in eroded Woolwich Beds and the borings in the blocks were probably a result of stranding in the intertidal zone. There is no evidence from the field surveys, however, that sources of the sandstone blocks were ever available on the east.

Smart (in Smart and others, 1966, pp. 14–15) gave a fully reasoned explanation of the trough-faulting, relating it to ground-ice effect, which nevertheless has been challenged by Gamble (1968, pp. 588–591; 1972, p. 476), who favours tectonic adjustment to deep-seated structure as the cause. SCAH

In 1976, the Oldhaven Beds section was as follows:

The thickness of the sand beds in the clay unit was noted to vary by as much as 300 per cent because of flowage resulting from faulting and post-depositional disturbance. RAE

Whitaker (1872, p. 270) saw only sand with the pebble bed in the lane south-east of Shelford Farm and in that south of Broadoak [Common], but another large pit [TR 167 604] was formerly worked on the west side of the road to Broadoak and about 0.5 km ENE of the last pit. The section of the Woolwich Beds has already been described (p. 36). Beneath 6.7 m of London Clay (p. 50), perhaps disturbed by slipping, were exposed 3 m or more of fine-grained speckled Oldhaven Beds sand with the basal pebble bed. In the drift-covered area on the north side of Sturry the Oldhaven Beds were only seen in section at some excavations, largely in gravel, around 600 m NW of Sturry church. Here fine-grained sands with clay overlie the pebble bed, which contains some comparatively large pebbles as well as blocks of ironstone.

The very extensive disused pit between Sturry and Westbere and 1 km NE of Sturry Station exposed the whole succession from Thanet Beds to London Clay. The Oldhaven Beds were well exposed in the main face on the north, maintaining a thickness of 5.2 to 5.6 m but showing a certain amount of lateral variation (Plate 5). At the west end [TR 183 612] the junction with the London Clay was obscured but the pebbles in the lower part were seen to be a conspicuous feature:

Farther east the pebble beds join and eliminate the intervening sand. More than half-way along the succession was as follows:

Near the eastern end of the face the beds were again more varied:

The top beds were similar in an old pit in the wood across the road on the east.

Three small pits at Westbere exposed Oldhaven Beds. The one [TR 192 612] 100 m NNW of the church showed 0.9 m of brown sand with a 0.15 m bed of pebbles, many of them very small, resting on Woolwich sands. Another [TR 193 614] 275 m NNE of the church, also exposed a metre or so of brown and buff cross-bedded sand and soft sandstone, underlain by the pebble bed resting on the Woolwich Beds (p. 36), while about 320 m ENE of the church similar beds were to be seen [TR 196 612] capping the Woolwich sands (p. 36).

In a bank on the hillside 0.8 km ENE of Westbere church, brown and buff fine-grained sand, with beds of brown sandstone and some ironstone, crops out from immediately under the London Clay. The hard beds are fossiliferous. Beyond this point the Oldhaven Beds are obscured by brickearth and made ground for 0.8 km but then become visible in the railway cutting [TR 214 620] SE of Chislet Colliery, as mentioned by Whitaker (1872, p.270). In 1946 the following section was noted:

About 0.8 km farther ENE the cutting [TR 221 622], though largely obscured, showed that underneath about 2.4 m of London Clay the fine-grained buff sands of the Oldhaven Beds are at least 3.7 m thick; scattered pebbles from the basal bed were thrown out from below rail-level. The next cuttings along the line are those nearing Grove Ferry (see below).

On the opposite side of the Great Stour an outlier of London Clay and Oldhaven Beds caps the high ground at Grove Hill but is largely covered by drift. An old gravel pit [TR 229 608] 140 m S of the highest point proved 1.2 m of Oldhaven Beds consisting of fine-grained sand with lenticular ironstone.

On the east bank of the Little Stour the Oldhaven Beds are present around Preston and Stourmouth. They flank two large outliers of London Clay but only to the west of Preston are they in places free of drift cover or exposed in pits dug through the latter. An old pit [TR 245 607] in a wood 230 m NNE of Preston Court exposed 1.8 m of firm fine-grained brown sand and a 0.45-m thick bed of large and small black pebbles resting on coarser-grained Woolwich sands (p. 36). In the disused pit [TR 247 614] on the south side of the road from Preston to Grove, Oldhaven sands were distinguished beneath London Clay and gravelly brickearth, but the subsequently worked pits [TR 249 617] north of the road were excavated through Head Brickearth into River Gravels of the 2nd Terrace which have cut back the Oldhaven Beds and occupied the position they would otherwise have taken on emerging from beneath the London Clay.

About 0.4 km SW of and the same distance northward of the church at Elmstone, south-east of Preston, the presence of two small outliers of Oldhaven Beds beneath the drift is inferred from the abundance of pebbles at these places.

Brown sand beneath 1.5 m of brickearth in a small old pit [TR 255 624] at Dean Farm appears to be Oldhaven Beds sand and the beds probably continue through West Stourmouth and follow round the London Clay which is inferred to occupy the higher ground but is nowhere free from a thick mantle of brickearth.

From Grove Ferry the outcrop of the Oldhaven Beds is continued in the valley north of Upstreet, through Chislet, round to Herne in a narrow tongue and northwards from the Ford valley to the coast west of Reculver. The sandy railway cuttings south-west of Grove Ferry now offer no clear exposures, nor does that west of the Station (Whitaker, 1872, pp. 168, 270). The typical pebble bed, 0.15 to 0.38 m thick, is recorded in the latter cutting, with rounded soft sandstone lumps probably derived from the Woolwich Beds. On the left-hand side of the lane leading from Grove Ferry Station towards Upstreet, a small sand-pit with many fossils was formerly seen (Brown, 1859, p. 133; Whitaker, 1866, p. 416; 1872, p.270). Whitaker showed conclusively that the succession here is normal and that only fossils typical of the Oldhaven Beds occur in these sands. Brown's inference that 'Upper Tertiary (Crag)' deposits occur here was partly based on misidentified material (see p. 52) but there also seems little doubt that nearby gravelly drift may have contributed Pleistocene mollusca to his collections from Grove Ferry (p. 77) and possibly included also a derived nodule with Pliocene fossils (pp. 53, 77).

Westward of the outcrop shown in the valley of the Saare Penn stream near Chislet Park, trial boreholes for a scheme of dam construction are reported to have penetrated through drift and a fringe of London Clay to reach sands of the Oldhaven Beds in the bottom of the valley. SCAH

Overgrown pits 0.8 km SW of Chislet Forstal and about 0.4 km SSW of Chislet church are two localities mentioned by Whitaker (1872, p.271), the former including the junction with the London Clay. Westward of Chislet the beds are covered by brickearth but near Old Tree and Maypole the yellow sands occur at the surface or are exposed where overlying thin gravels have been dug off. The road cutting north of Millbank (see also p.37) provided Whitaker (1872, p. 169) with a good section in Oldhaven Beds and Woolwich Beds; the pebble bed was more than 0.6 m thick in places. He also mentions a shallow pit on the western side of the road, above the cutting, where fine-grained whitish sand was seen beneath gravel. The pit [TR 202 654] 0.2 km NW of Millbank in 1938 exposed rather more of the Oldhaven Beds than Whitaker saw, as follows:

Towards Herne the pits are overgrown at two localities (some 0.8 km W of Ford) mentioned by Whitaker (1872, p.271). The pit [TR 190 660] that he saw just south of Hawe Farm, however, exposed the following beds in 1938:

Whitaker obtained shells from the local ferruginous bed.

The tongue of Oldhaven Beds at Herne is narrower and extends less far than was formerly thought; also there is no inlier of Woolwich Beds (see p.37). The section, less than 0.4 km NE of the church, from which Whitaker collected more fossils has since become much degraded, but the junction with the London Clay (p.49) was seen in the adjacent road cutting [TR 185 661].

On the northern side of the valley east of Herne, sand and pebbles show locally in the soil and a small pit [TR 199 662] 0.5 km S of Broomfield exposed 2.7 m of cross-bedded sand beneath the basal beds of the London Clay (p. 49). Whitaker (1872, p. 169) noted Oldhaven Beds sand and the pebble bed occurring in the lane cutting southward of Broomfield and also saw the sand in a small pit to the east (1872, p.271). At all these localities and at an old pit [TR 206 664] 0.4 km SSW of Heart in Hand, however, the beds are overlain by gravel.

Beyond Highstead the sands are practically free from drift and give rise to soils in marked contrast to those of the London Clay capping the plateau on the west. A section [TR 225 677] on the coastal road just west of the Roman Galley inn, east of Hillborough, showed buff sand with the pebble bed overlying the coarser-grained Woolwich Beds sands (p. 37). Oldhaven Beds are present, on the south side of the railway, at the top of the western part [TR 219 679] of the cutting near Brook Farm, southward of Reculver. The pale sands, with clayey beds and pebbles below, which Whitaker (1872, p.90) referred to the Woolwich Beds are undoubtedly Oldhaven Beds resting on Woolwich Beds sands below (p. 37). Similar sands with the pebble bed, resting on coarse-grained sand, were seen about 50 m SW of the cutting. The road cutting north-east of Hillborough exposed brown clay and the pebble bed at a point [TR 216 684] 450 m NE of the church; the interpretation of this section agrees with that given by Whitaker (1872, p.90).

The Oldhaven Beds present one of the most striking features of the coast section (Plate 1). About 5.5 m thick, the sands, though loose, stand in an almost vertical face and lenses of ferruginous sand and shelly iron-sandstone are conspicuous; the 0.6 to 0.9 m of basal sands and clays include the pebble bed, which varies from 0.03 to 0.46 m in thickness but shows up throughout in marked contrast to the Woolwich Beds sands beneath. Concretionary rosettes of baryte occur in the sands and sharks' teeth at their base (Pitcher and others, 1967, p.28). The section has been visited and described many times (Gamble, 1968, p. 591) and it was Oldhaven Gap, at Bishopstone, that furnished Whitaker (1866, p. 413) with the name for the series which Prestwich had previously grouped with the basement bed of the London Clay. The following include full descriptions of the beds: Prestwich (1850, p. 265; 1854, p.111); Dowker (1864, p. 342); Whitaker (1864, p. 60; 1872, pp. 170, 271; 1912, p. 248); Morris (1870, p.39); Gardner (1883, p.205); Leighton (1894, p. 375); Young (1910, p.257); Brown (in Dewey and others, 1925, p.272); J. E. Cooper (1934, p. 5). The section [TR 214 690] in the cliff about 1400 m W of the ruined church at Reculver in 1938 showed:

About 320 m farther westward the basal Oldhaven Beds contain two layers of pebbles separated by a few centimetres of coarse-grained ferruginous clayey sand. A further 500 m beyond this, at a point [TR 206 687] some 140 m west of the Bishopstone ravine (= 'Oldhaven Gap'), the beds at the base consist of 0.23 m of coarse-grained ferruginous glauconitic sand with dark grey shaly lenses and pebbles resting on 0.13 m of coarse-grained yellow sand with loose pebbles. Only a few metres beyond this, similar ferruginous basal beds expand to over 0.6 m but the pebbles are restricted to the bottom 0.18 m. Overlying these beds are homogeneous buff sands with shells. At about 320 m W of the Bishopstone ravine the following section [TR 204 687] is typical of a local shelly development in a varied sequence of clayey and pebbly basal beds:

Within 0.4 km of the last section the Oldhaven Beds are at beach level or they are lost to sight beneath the London Clay and its land-slipped masses. On the shore, the outcrop is marked in part by a projecting reef of Oldhaven Beds pebbles known as The Rand. A feature of the topmost Oldhaven Beds is the development of flat lenses of sulphur-yellow sand. Calcareous doggers, as well as lenticular masses of brown clay also occur in the sands generally, and opaque selenite is sometimes found. The thin clay intercalations like London Clay are either compact or shaly. The shelly seams contain sharks' teeth and there are indurated ironstone bands. In the largely decalcified upper half of the sands selenite typically occurs in the form of 'sand roses'. SCAH, SB

London Clay

Some two-thirds of the map-area is occupied by London Clay, which dominates particularly the Isle of Sheppey and the Blean country southward of Whitstable and Herne Bay. Drift cover masks the clay only locally except near Preston, where it is hidden under brickearth, and in the alluvial tracts bordering the Swale. The total thickness of the formation is estimated at 145 m, a figure which agrees well with one obtained by Prestwich (1854, p. 406). Davis (1936, p. 342) has assumed a total of nearly 160 m, but this figure is a slight over-estimate.

The magnitude of the coastal sections and the former existence of a trade in pyrite and septaria collected from the beaches led to early attempts to elucidate the succession in the cliffs of north-east Kent, the oldest by Richardson (1834, p. 78; 1841, pp. 211, 213). The whole sequence was subsequently treated systematically by Prestwich (1850, p. 265, etc.) and fully described by Whitaker (1864, p.60; 1872, pp. 170, 290, 293) who, in the Geological Survey Memoir on the London Basin, included the field notes by Hughes. An interesting account of early fossil collecting in the Isle of Sheppey (see also p. 1) has been given by Bingham (1861, p. 92). Carruthers (1875a, p. 318) discussed the London Clay flora of Sheppey, later to be dealt with so exhaustively by Reid and Chandler (1933, p.22) and by Chandler (1961, pp. 36–37) for Sheppey, Swalecliffe and Herne Bay. Davis (1936, p. 328; 1937, p. 77), from a study of both fauna and flora, has provided the best general account of the London Clay of Sheppey.

In the present district the clay usually has at the base only a thin sandy bed, with a few pebbles; above this the clay may be somewhat shaly for a metre or so but rapidly passes into a compact, stiff, fine-grained tenacious dark blue clay of entirely uniform lithology. Towards the top, however, the beds tend again to contain a certain amount of fine-grained sand, either as thin seams or admixed with clay, even at some 50 m below the level at which they grade into the Claygate Beds (p.50). Calcareous concretions termed claystones (septarian nodules) veined with calcite vary in abundance according to the horizon; at some levels they may be present in numerous bands only 0.6 or 0.9 m apart, at others they are rare. In weathered clay, pyrite and selenite are common. Animal and plant remains, including fossil wood, occur in varying quantities in different beds but are always much easier to procure where erosion has been active. Most of the clay weathers to a dark brown or chocolate colour, or, at the surface, sometimes to a yellow shade.

Whitaker (1872, p. 275) summarised previous views of Prestwich and others on climate and deposition relating to the London Clay–warm or even tropical conditions were recognised, and the quiet accumulation of muddy sediment persisted while the sea floor subsided very gradually. Stamp (1921, pp. 63, 72, 73, 100) has drawn attention to several interesting features of London Clay deposition. The generally attenuated pebble bed of the present district he takes to indicate increased distance from the source of origin. This deduction must now be qualified, however, with the observation that local thicker developments of pebbles, e.g. at Herne (see p.49) and possibly on the south-west of Herne Bay (where 3.7 m of clay and pebbles are recorded from a well-boring), show that Oldhaven Beds shoal conditions still lingered on locally in early London Clay times. Stamp's statement that fossils, especially the fresh-water reptiles, from Sheppey seem to indicate proximity to some land, presumably on the south, is in accord with that interpretation. Barrow (1919, p. 2) noted that the pebble beds at the base of the London Clay in the London district are very variable in thickness and in size of the pebbles, and Hester (1941, p. 311) noted further that two pebble beds may be observed locally in north-west Middlesex, features which are both paralleled in north-east Kent. There was relatively little disturbance of the underlying Oldhaven sediments during the gentle incursion of the London Clay sea. Stamp (1921, p. 73) had suggested, indeed, that the Oldhaven and Blackheath Beds and the London Clay Basement Bed are the products of a single transgression, but this view is on regional grounds challenged by Curry (1965, p. 160), who also believes, however, that no diachronism has yet been proved for the basement beds.

Essentially the fauna of the main mass of the London Clay is marine and characteristic of calm waters. Curry (1965, pp. 159–162) has reviewed the knowledge that has accumulated on conditions of deposition of the London Clay, particularly from studies of this fauna. The London Clay was 'formed in a large sea, which, near London, was at times over 100 fathoms (180 m) deep'. In the London Clay Basement Bed, accumulations of marine molluscs are accompanied by a restricted foraminiferal fauna and both suggest deposition in shallow sea water. There is to date not much to be gained from attempts to formulate a faunal zonal scheme for the London Clay, a problem posed 'ever since the time of Wetherell' and not effectively solved either from studies of the macrofauna or ostracods and foraminifera. Curry emphasises that 'some of the faunal patterns to be observed in the London Clay are facies-controlled'. Foraminifera, such as Globigerina, in association with crinoids, Terebratulina and certain molluscs, including Arctica and Astarte, may indicate cold (because deep) water of the order of 100 to 200 fathoms (180 to 360 m), an inference that is not contradicted from evidence of a tropical flora when by analogy with present-day conditions sea-water temperature at 200 fathoms depth might be no more than 50° F. (10° C.) if the mean surface temperature were 70° F. (21° C.). The London Clay flora (over 500 species, mostly of fruits and seeds) was derived from a tropical rain forest in an area of heavy rainfall and high temperature (Chandler, 1961, p. 21; and see below). The uniformity and fineness of grain of the London Clay suggest both distance from land and freedom from strong currents.

The presence of seeds in great variety is not inconsistent with these conclusions for, in their study of the London Clay flora, Reid and Chandler (1933, p. 19) include an illuminating quotation from the Challenger Expedition report of 1892 which describes conditions some 100 km beyond the mouth of the Ambernoh river in New Guinea and which are considered to be analogous to those of the London Clay period in England–a sea encumbered with the river-borne debris of drift-wood, together with various fruits of trees, among which swarmed cirripedes, hydroids, gastropods, crustacea etc. and especially, as emphasised by Davis (1937, p. 77), an abundance of fish. Fossil palms have long been known but more recently the occurrence of mangroves in the London Clay was proved at Sheppey and Herne Bay (Chandler, 1951, p. 271; 1961, p. 28), confirming the conclusions of Reid and Chandler (1933, p. 88) that the climate was such as to allow the existence of a flora of the tropical rain-forest type. Chandler (1961, pp. 27–31) reviewed new work on phytogeographical relationships and climate that has emphasised the features the London Clay flora has in common with the vegetation of Indo-Malayan and south-east Asian forests, including the richness in genera and species and a high proportion of trees and shrubs. Miss Chandler also draws attention to the conclusions from plant physiognomy reached by Edwards (1936, pp. 25–27), who pointed out that a preponderance of dicotyledonous trees with entire leaf-margins, as in the London Clay, is a characteristic of tropical rain forests. The high humidity essential for the growth of Magnolia, which is abundant in the London Clay, is another important point mentioned by Miss Chandler. Significantly, it appears that at the beginning of London Clay times a tropical flora was already well established and that this persisted throughout with no general change of character. In Miss Chandler's subsequent volumes that were issued from 1961, a summary, revisions and a. general review of Lower Tertiary Floras are included in Volume IV (1964); as pointed out by Mont-ford (1970, pp. 187–191), the picture of Palaeogene floras is much clarified by this account, which has particular relevance to the London Clay as providing a special sample of vegetation in a Nipa belt that happens to include Sheppey and Herne Bay. It is now realised that as the plant fossils in the various Tertiary beds of southern England vary, so do they represent just different samples of the same general kinds of vegetation, their nature governed by differences of place, transport and method of fossilisation.

The London Clay flora is an admixture of lowland and upland species. The palm Nipa and the fruits and pollen of mangroves are indicators of the muddy estuaries and highly organic coastal swamps that fringed the London Clay sea; behind this belt lay the lowland tropical rainforests with a great variety of species, Lauraceae, liane families and some water plants among them; on the higher lands behind the rain forest grew Magnolia, Juglandaceae and conifers such as Pinus, Sequoia and Araucaria. On analogy with modern tropical forests the mean average temperature for the London Clay forest has been estimated at 25° to 26°C. In making comparison of fossil plants with modern types it is important to realise the tremendous numbers of the latter. As Montford explains (1970 p. 188), the Malaysian region carries some 20 000 species of flowering plants, so it is not surprising that, through lack of adequate description alone, many of the London Clay fossils have not been matched.

With the completion of her researches, Miss Chandler has been able to accept the view that throughout America as well as Europe and Western Asia there generally prevailed from the early Eocene a greater measure of warmth and humidity than was formerly thought. As there are close comparisons of the London Clay flora with that of the modern tropical belts of the Old and New Worlds, and as it is clear that such belts have migrated in a world-wide manner during geological time, there is no longer any need to postulate special factors of communication to account for an Indo-Malayan type of flora reaching Europe in the London Clay (Chandler, 1964, pp. 58–59).

Wrigley (1924, p. 251; 1940, p. 240) showed that the London Clay around London may be separated into five divisions additional to the Basement Bed, determined on faunal evidence. Such data that are available from fossils collected in the Sheppey and Herne Bay areas have failed so far, however, to throw any more light than could Wrigley himself on extending his scheme to those regions; the fact that few fossils are ever found in situ in the cliffs admittedly does not help matters. The summary given is based essentially on details of lithology, which are more accurately known, but some points of correspondence with Wrigley's sequence for the London area are significant. The clays with Isselicrinus and nodular concretions clearly represent Wrigley's Second Division 'at about 100 ft [30 m] above the Basement Bed' and his Third and Fourth Divisions probably occupy most of the sequence above. Nevertheless, it seems unlikely that the Fifth Division is wholly unrepresented. Davis (1936, p. 337) has pointed out that, though 'the distinctive fauna of the Upper London Clay (Highgate Archway, Tolworth) is not present at Sheppey'; this means only that, in contrast to the upper sandy clays around London, the stiff clay type of sedimentation persisted in Sheppey. In fact, however, while recognising that there is around London a more distinct change to strongly sandy clays in bulk, it is demonstrable that there is in Sheppey too a characteristic development of thin sandy seams and lenses in somewhat shaly clay in the top beds of the London Clay, especially within the uppermost 15 m. It is likely that the changing conditions exhibited by these beds would have influenced their fauna to some extent.

As pointed out by Chandler (1961, pp. 31–32), Wrigley had concluded that no individual faunal species or genus is known to be confined to one horizon or division nor does any group show successive evolutionary changes. Though modifications in the fauna may be determined by change of facies, those in the flora depend essentially on climate and ecological conditions. Chandler in her later summary (1964, pp. 60–61) cites researches on pollen, notably from Sheppey and Herne Bay, that have confirmed the suspected conclusion from studies of the macroflora: that there were no marked floral changes throughout London Clay time.

Davis and Elliott (1958, pp. 269–271), in their completed palaeogeographical studies from London Clay fossils, have concluded that the flora grew along the flats bordering the south-westerly extension of the London Clay sea, which opened and deepened towards the present North Sea. These authors have provided a valuable historical review and stratigraphical summary (pp. 256–259) which considers Sheppey and Herne Bay in the context of the London Basin as a whole. They also include a useful commentary on the fossil remains (pp. 264–270) and the evidence these offer on environment and distribution. The authors suggest that the wealth of fossil fruits from the upper beds in the Isle of Sheppey do indicate an actual provenance of local original abundance there.

Curry (1965, p. 162) refers to the abundance in the London area of diatoms and some radiolaria in the lowest 15 m of clay above the basement bed, and sporadically at higher levels; as no other fossils except fragments of unbored wood occur in such beds he concludes that foul bottom conditions probably obtained 'with organisms confined to a thin sheet of water at the surface of the sea'.

The following summary of the general succession of the London Clay in north-east Kent has been pieced together from data obtained from widely varying localities and horizons (especially Sheppey and Herne Bay, see pp. 47– 48), and from the record of a borehole at Sheerness, west of our area, described by Shrubsole (1878, p. 355). The three uppermost divisions, and a little of the fourth, are exposed in Sheppey; much lower in horizon, the clays with Isselicrinus are found near Herne Bay.

There are no sharp lines of demarcation between the groups except at the Basement Bed.

Details

Coastal sections

The eastern half of the Isle of Sheppey is included in the Faversham area. The London Clay is much disturbed by periodic landslipping where it crops out along the cliffs of the northern coast. Additional to the work of Hughes, the late Mrs E. M. Reid and Miss M. E. J. Chandler and the late Mr A. G. Davis, quoted above, are accounts of excursions by Carruthers (1875b), Shrubsole (1881; 1887) and by Davis and Elliot (1951, p.269; 1954, pp. 383–384). Pitcher (in Pitcher and others, 1967, pp. 25–66) has provided practical notes for the geological visitor.

In the Sheppey cliffs about 60 m of London Clay are exposed below the Claygate Beds. A series of zones of weathering, red, green and brown from the top downwards, appears to have no strati-graphical significance and these are not present where there are overlying Claygate Beds and Bagshot Beds. The London Clay may be compact or shaly and contains thin sandy seams and lenses. Bands of septarian nodules, up to 1 m across, occur commonly; less frequently pyritous nodules are found. Selenite crystals occur throughout and are very common at some levels. Fossil wood is usually abundant, either large and bored by Teredo or in small pieces free from this. Flint pebbles are found rarely, sometimes partly decomposed and associated with septaria (Davis, 1937, p. 77). SCAH

In 1938, a section [TQ 997 730] 1.2 km NW of Mud Row showed the following:

At the headland (Draper's Point), about 0.4 km eastward, the section [TR 001 730] in the cliff was:

The section [TR 020 725] at Warden Point was:

At Warden the cliff [TR 023 719] exposed:

Davis (1936, p. 331) has summarised the Sheppey cliff sequence, separating the following divisions:

Davis showed that fossil material, long known in the detritus on the beach, is essentially derived from the huge fallen masses of the Sheppey undercliffs; it is found from high water-mark level up to 10 m above. No collecting sources were located, however, in the undisturbed clays of the cliffs above and no evidence was found of any lateral variation of the fauna between Minster and Warden. Careful search eventually resulted in the finding of Nipa fruits and smaller fruits and seeds in the exposed faces of the landslipped masses (Davis, 1936, p.341). Collecting that is nowadays exactly localised is still necessarily determined, for the best specimens, by the availability of fallen material on the shore. For example, a well-preserved and diagnostic specimen of a turtle, Eochelys crassicostata was obtained from a large septarian nodule at 10 to 20 m from the cliff face [TR 023 722] between Warden Camp and Warden Point (Moody, 1968, pp. 129–140).

At Leysdown and from Seasalter to Whitstable the London Clay at the coast forms only low cliffs, and at Tankerton, where the cliff is higher it is obscured by landslipping and artificially reconstructed ground. Trial borings at Whitstable have proved stiff clay with relatively few septaria down to –2.6 m OD. Below this, however, it is probable that the lower beds containing many bands of septaria underlie the deposits of the foreshore. A concealed outcrop of these hard bands may have influenced the accumulation of shingle which forms the projecting bank known as the Street Stones.

The clay was exposed near Swalecliffe, west of the stream, the low cliff [TR 136 677] showing some 1.8 m of brown and buff clay becoming greenish blue below, with bands of septarian nodules. Reid and Chandler (1933, p.25) found relatively few fossils here other than pieces of wood and twigs but Chandler (1961, pp. 36–37) was later able to say that a number of workers had collected much additional material from Division 2 of the London Clay in the Herne Bay area; they had now shown that fruits and seeds may occur as abundantly to the west of that town as they do to the east, and that Nipa occurs along both parts of this coast. The cliff [TR 151 678] at Stud Hill exposed up to 15 m of blue and chocolate clay with septarian nodules. Richardson (1841, p.212) saw the cliff when erosion had exposed a mass of Eocene vegetation, and the skull of the mammal Hyracotherium leporinum was then discovered (see also Chandler, 1961, pp. 25–26, 136). At Hampton and through much of Herne Bay brickearth practically reaches the shoreline and the clay is poorly exposed. SCAH

From Herne Bay to Bishopstone extensive landslipping again obscures the cliffs. A series of trial-borings, however, proved stiff clays with many bands of septarian claystone, exceptionally as frequent as some 15 bands in a 10- m sequence. Sandy clays of the basement bed were proved 0.9 to 2.4 m thick locally. The base of the London Clay is at –11.9 m OD on the west, rising to –7.9 m OD at Beltinge Cliff and to + 4.9 m OD where the Oldhaven Beds begin to emerge 0.8 km W of Bishopstone. About this locality [TR 201 686] the following section was seen in the foreshore:

In the cliff east and west of the ravine at Bishopstone ('Oldhaven Gap' of Whitaker) Prestwich (1850, p. 265) saw his classic section. The significance of the basal green sand with flint pebbles was not appreciated, however, till a later date (see Prestwich, 1854, p. 130, footnote; Whitaker, 1862, p.270; 1866, p.412). The full section of the Tertiaries given by Whitaker (1872, p. 170) has details of the Basement Bed and shows the lenticular nature of the green sand. Gardner (1883, p. 206) emphasised that the Basement Bed here forms a unit very distinct from the mass of the London Clay; he also described a section farther west showing details of the junction and of lenticles in the Oldhaven Beds below. Leighton (1894, p. 375) gave details of the London Clay and its Basement Bed at Herne Bay as seen by Whitaker and himself, and Stamp (1921, p.63) noted the affinity with the Oldhaven Beds which is indicated by the streaks of very similar clay therein, below the bed of small pebbles in this section. In his description of the cliff section between Herne Bay and Reculver, Brown (in Dewey and others, 1925, p.271), referring more especially to the 30 m landslipped cliff at Beltinge, stated that much selenite occurs in the clay, pyritised wood washed out of it is common on the foreshore and that the fauna, though not so rich as at Sheppey (see also Reid and Chandler, 1933, p. 25), contains Isselicrinus subbasaltiformis and other fossils which appear to be usually restricted to the lower part of the London Clay; the sandy base including a 0.15 m thick bed of sandy clay with occasional flint pebbles and sharks' teeth.

From Bishopstone to within 1.2 km of Reculver London Clay caps the sandy cliffs. The section [TR 214 690] near the point of disappearance of the clay from the cliff showed the following beds resting on the Oldhaven sands:

As on Sheppey (p.47) most effective collecting from the London Clay at the Herne Bay coastline has relied on foreshore material. In recent years special field techniques have improved the results from examination of pyritic concentrates. The discovery of an uncrushed beetle larva preserved in pyrite was of special interest (Rundle and Cooper, 1971, pp. 293–295), and it is probable that the larva derived as a wood-boring type from drift wood in the London Clay sea. It is also notable that 'pyritisation of the organism was well advanced before the animal decayed'. SCAH

Inland sections

Exposures are rare in the eastern part of the Isle of Sheppey, but an old pit [TR 008 716] was noted 0.5 km S of Mud Row and there was formerly a brickworks near the cliff at Warden. The clay gives rise to a very heavy soil diversified only by thin pebbly downwash locally. It was formerly considered that the numerous mounds in the alluvial tract bordering Sheppey and the Isle of Harty were of London Clay with a mantle of clay wash (see Hughes in Whitaker, 1872, p. 292). It is now thought, however, that many of these were raised artificially (see p. 96).

Stiff clay soil, with flints and pebbles only on the higher ground, covers the Isle of Harty. Some 700 m ESE of Sayes Court brown and grey shale with septarian nodules was seen [TR 029 660] bordering the marsh.

South of the Swale the lower part of the London Clay occupies the rising ground about Romacres and north-north-east of Oare; at the surface it presents a sticky yellowish slightly loamy character. In several old workings around Uplees rather loamy clay was formerly dug, in places apparently reaching the sandy base of the London Clay. Mottled orange and grey glauconitic sandy clay of this horizon was detected near Court Lodge; the two small outliers on the west side of Oare are of similar material, with sticky clay at the top of the hills.

Faversham Creek is bordered on the north-east side by the dissected ridge of London Clay on which Nagden is situated. Eastward of this the clay presents featureless tracts of heavy land continuous with the wooded higher ground of the Blean southward of Whitstable. On the south side of Graveney Marshes and Seasalter Level London Clay forms two large, gently rounded, low hills, Denly Hill (Plate 8) and another 2 km to the east; several of the other, smaller, hills in this area, however, were proved to be mounds of stiff alluvial clay thrown up artificially in medieval times (see p. 98). Graveney Hill and Cleve Hill are part of a London Clay mass almost surrounded by alluvium. Just east of Sandbanks was seen [TR 040 626] 0.46 m of stiff clay, sandy at the base, the London Clay basal bed of a small outlier, overlying Oldhaven Beds sand (p.40). Whitaker (1872, p.294) saw the base of the London Clay where it is exposed [TR 061 630] in the railway cutting 0.8 km ENE of Graveney church and he also saw laminated grey clay at this horizon west of the road junction at Waterham. Two small outliers south of Fostall give rise to local very stiff soil.

In the Blean a section in laminated grey clay of the Basement Bed was seen by Whitaker (1872, p. 294) by the road 0.8 km NE of Hernhill. Around Holly Hill are the remains of numerous shallow workings in the stiff clay of the bulk of the formation, but in the Blean generally exposures of the London Clay are few. A shallow railway cutting west of Tyler Hill was in stiff brown clay, and at the northern end of the former tunnel south of this the clay contains typical septaria. Along the coastal road, about 7.5 m of stiff clay with a few septarian nodules is cut [TR 090 634] in the descent to the valley 0.5 km west of Fox's Cross, and stiff brown clay was excavated to 4.6 m in the cutting [TR 100 646] about 1.5 km farther north-east. The cuttings on the old Whitstable railway at Clowes Wood and South Street were in featureless stiff buff and brown clay. Clay lies at the surface over most of the area of Thornden, West Blean and East Blean Woods, with only a very thin mantle of friable soil and drift on some of the rising ground in the vicinity of gravelly patches. Many of the deep valleys of the Blean have their streams incised into practically solid clay.

The railway cutting [TR 119 665] 0.4 km E of Whitstable Station is in chocolate clay, to a depth of 10.7 m; similar clay was visible in the cutting 0.4 km SE of the Station and along the coastal road about 1.5 km to the east of the Station. Towards Herne Bay the clay is at several places cut again by the coastal road, but a better exposure [TR 142 670] was seen in some shallow workings 275 m N of Bodkin Farm, where buff coloured clay was dug off revealing darker, blue clay forming the floor.

The railway west of Herne Bay Station cuts through brickearth into the London Clay, which is further seen in the cuttings south of Beltinge and Hillborough. A trench [TR 162 667] 1.2 km SW of the Station proved septaria in the clay. Near Bullockstone and at Strode Park the soil contains numerous black pebbles, both large and small, but stiff grey to orange-weathered clay is everywhere present though locally it is fairly fissile in character. It would appear that the lower part of the London Clay may hereabouts include an abnormally thick development of the type of clay found just above the sands of the Basement Bed. In a ditch [TR 168 657] on the hillside 600 m SW of Strode Farm a bed of pebbles may be in situ in the clay; but if so it can hardly be less than some 10 m above the base.

At the village of Herne, Whitaker (1872, p. 171) saw small sections 0.4 km or more north-north-west of the church which exposed 'a bed of black flint-pebbles in brown clay, resting irregularly on rather coarse green-grey sand'. This pebble bed and also the pebbles mentioned in a later chapter (1872, p. 271) as common at the western part of Herne churchyard, he referred to the Oldhaven Beds, but London Clay is present near the eastern border of Strode Park and it is concluded that the pebbles mark the Basement Bed. These pebbles are here more strongly developed than elsewhere, as well as apparently occupying a greater thickness of clay, but they tend to differ from the Oldhaven Beds type in lacking uniformity of size. Whitaker also noted that London Clay was present in the sand-pit less than 0.4 km NE of the church, and the junction with the Oldhaven Beds was well exposed in 1938 in the adjacent road cutting [TR 185 661], where about 0.6 m of sandy shale rests on yellow sand. Similar sandy clay and shale overlie the Oldhaven Beds in the pit [TR 190 660] just south of Hawe Farm where Whitaker saw a 'small lenticular mass of light-green sand' at the bottom of the clay.

East of Herne, a small pit [TR 199 662] 0.5 km S of Broomfield exposed the following:

Ochreous mottled and blue-grey clay and clayey sand mark the London Clay base along the hillside from Hillborough to near Highstead. The clay 0.8 km W of Ford (formerly Hoathborough) which Whitaker (1872, p.294) regarded as an outlier is now shown to be an extension of the main outcrop. Near Chislet and Upstreet the stiff clay soil is locally much modified by sandy and gravelly wash from the considerable drifts in that area. SCAH, SB
In the valley of the Great Stour over 10 m of beds of the London Clay were seen in section at the top of the large pit [TR 162 602] about 0.5 km S of Shelford Farm:

The London Clay in this pit was seen to greater advantage by Smart around 1952–53 (Smart and others, 1966, pp. 198–199) who noted an irregular base. In the 6.1 m of the blue shaly clay he observed some flattened (ferruginous) nodules, selenite and pyritised wood; the bedding was commonly disturbed. In the 1966 description given by Gamble (1968, p. 589) a total of over 20 m of London Clay had become exposed. SCAH

In 1976, the distinction between the lithologies of the Oldhaven Beds and London Clay was not so clear, although the basal pebble-bed was weakly represented. The section noted in the southern face beneath 2 m of intensely cryoturbated flinty clayey Head deposits was as follows:

This section demonstrated that the boundary between the Oldhaven Beds and London Clay can locally be transitional in nature. RAE

Another large pit [TR 167 604] now disused, on the west side of the road to Broadoak and about 0.5 km ENE of the last pit, exposed some 6.7 m of the London Clay, at the top of the section, consisting of stiff grey to blue clay, partly chocolate weathered, with a thin shaly base including sand and glauconite. Between Sturry and Westbere, the extensive disused pit about 1 km NE of Sturry Station showed the following section of the London Clay in the northern face:

East of Westbere, at Hoplands stiff chocolate clay was noted in an overgrown pit [TR 206 617], and 0.5 km SW was another old pit [TR 202 615] showing clay with pebbles, presumably from the Basement Bed. The railway cutting [TR 214 620] south-east of Chislet Colliery cuts into about 6 m of stiff clay with a 0.15-m thick shaly and sandy base resting on the Oldhaven Beds. Whitaker (1872, p.294) saw a clearer section here, in which grey very shaly clay, with here and there a pebble at the bottom, rested on the Basement Bed. The latter consisted of brown loam, with green grains and a few pebbles, about 0.2 m, overlying a thin inconstant bed of sand comprising fine alternations of buff and green grains. This bed appeared to dovetail into the bed above; it rested on sands of the Oldhaven Beds.

The cutting [TR 221 622] about 0.8 km farther east-north-east is also in stiff clay, to about 2.4 m on Oldhaven Beds sands.

An outlier of London Clay at Grove Hill, eastward of Stodmarsh, was proved in 1946. The clay is touched in two old pits dug through the Head Gravel. Similarly London Clay occurs over a wide tract near Preston and Stourmouth, though for the most part it is obscured by brickearth and gravel drifts. On the south it was possible to trace the basal sandy clay with a few small pebbles, and pinnacles of the clay were seen in the degraded workings [TR 249 614] 0.4 km NW of Preston Street. Apart from an area of bare clay on the rise 0.8 km N of Preston Street, the remaining London Clay is completely mantled with brickearth, including the separate outlier, inferred from data on the Oldhaven Beds, occupying the higher ground at Stourmouth.

Claygate Beds and Bagshot Beds

These beds are found in north-east Kent only in the Island of Sheppey, where, on the high ground, they overlie the London Clay. An average figure of 3 m may be taken for the thickness of the Claygate Beds, which are essentially passage beds from the London Clay, which itself is sandy in the upper part, to the sands of the Bagshot Beds, of which not more than 10 m are present in this area.

Sands described as Bagshot Beds have long been known in Sheppey (see Weston, 1854, p. 399; Prestwich, 1854, p. 406) though their early determination was accepted with caution. The recognition of Claygate Beds, which characterise the series above the London Clay in Surrey (see Dewey and Bromehead, 1921, p.38) is a result of the present resurvey. Whitaker (1864, p. 61) briefly described the Bagshot Beds of Kent but more detail of the Sheppey section is given by Hughes (in Whitaker, 1872, p. 317) for a locality just west of the area, on the Chatham (272) Sheet.

In lithology the Claygate Beds show a predominantly mauve colour and a large proportion of the material is clay, alternating in even beds with sand and loam.

The Bagshot Beds also contain clay, in thin seams, but show a preponderance of sand, either pale yellow or more or less ferruginous. They are more irregularly bedded but may contain persistent beds of buff and grey laminated clay. No pebbles have been seen in the sands but their relative abundance in overlying drift and washes therefrom suggests that original pebbly Bagshot Beds in the area may have been removed by denudation.

Correlation with other areas is indefinite, for no fossils have been found, but it is clear that the lithological series marks a return to shallow-water conditions such as obtained when the sands below the London Clay were deposited.

Details

Claygate Beds

The cliff section [TQ 982 732] at a point about 600 m NE of Punnetts showed Claygate Beds, about 3.7 m thick, between the Bagshot Beds sands and the London Clay (see the section given under Bag-shot Beds below). In the cliff about 200 m farther east the section [TQ 983 731] was as follows:

If the yellow sand is undisturbed Bagshot Beds then the Claygate Beds have thinned considerably.

Inland the Claygate Beds appear at the surface where the valley of the stream (Boarer's Run) through Punnetts has been cut down to them. Southward and eastward again the beds have a narrow belt of outcrop fringing the main mass of the Bagshot Beds and the several small Bagshot outliers around Eastchurch. Springs are frequently located at the junction with the impervious London Clay. SCAH, SB

Bagshot Beds

The following section [TQ 982 732] was observed in the cliff about 600 m NE of Punnetts:

The main spread of Bagshot Beds extends some 1.2 km southward from the coast, but on the highest ground it is overlain by gravels. A number of small outliers cap hills near Eastchurch, the more important being the paired ones on the east and south of this village, where yellow and buff clayey sand was seen in a few places. SCAH, SB

References

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CHANDLER, M. E. J. 1951. Note on the occurrence of mangroves in the London Clay. Proc. Geol. Assoc., Vol. 62, pp. 271–272.

CHANDLER, M. E. J. 1961. The Lower Tertiary Floras of Southern England; I (1960), Palaeocene Floras, London Clay Flora (Supplement). (London: British Museum (Natural History.) )

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COLLINS, I. and GILL, D. M. C. 1923. Notes on the geology of Boughton-under-Blean, with Report of Excursion. Proc. Geol. Assoc., Vol. 34, pp. 300–313.

COOPER, J. E. 1934. Oldhaven and Thanet Sand Mollusca of Herne Bay. J. Conchol., Vol. 20, pp. 4–8.

CURRY, D. 1965. The falaeogene Beds of South-East England. Proc. Geol. Assoc., Vol. 76, pp. 151–173.

DAVIS, A. G. 1936. The London Clay of Sheppey and the location of its fossils. Proc. Geol. Assoc., Vol. 47, pp. 328–345.

DAVIS, A. G. 1937. Additional notes on the geology of Sheppey. Proc. Geol. Assoc., Vol. 48, pp. 77–81.

DAVIS, A. G. and ELLIOTT, G. F. 1951. Field meeting in Sheppey. Proc. Geol. Assoc., Vol. 62, p. 269.

DAVIS, A. G. and ELLIOTT, G. F. 1954. Field meeting in Sheppey. Proc. Geol. Assoc., Vol. 65, pp. 383–384.

DAVIS, A. G. and ELLIOTT, G. F. 1958. The palaeogeography of the London Clay Sea. Proc. Geol. Assoc., Vol. 68 [for 1957], pp. 255–277.

DEWEY, H. and BROMEHEAD, C. E. N. 1921. The geology of South London. Mem. Geol. Surv. G.B.

DEWEY, H. WOOLDRIDGE, S. W., CORNES, H. W. and BROWN, E. E. S. 1925. The geology of the Canterbury district. Proc. Geol. Assoc., Vol. 36, pp. 257–284.

DOWKER, G. 1864. Excursion to Herne Bay and Reculver. Proc. Geol. Assoc., Vol. 1, pp. 339–344.

EDWARDS, W. N. 1936. The flora of the London Clay. Proc. Geol. Assoc., Vol. 47, pp. 22–31.

GAMBLE, H. J. 1968. Field meeting to East Kent. Proc. Geol. Assoc., Vol. 78 [for 1967], pp. 587–593.

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Chapter 7 Palaeontology of the Palaeocene and Eocene formations

The Thanet Beds were first named (as Thanet Sands) and described in detail by Prestwich (1852), whose account included sections of the cliffs of Thanet and descriptions of some of the fossils by Morris. Gardner (1883, pp. 197–210) described the Reculver coast-section in detail, mentioning two principal shell-beds. The lower was to be seen at the base of Reculver Cliff, where the commonest fossils were said to be the bivalves Arctica morrisi, Pholadomy a konincki (now rare) and Thracia oblata. This bed also contains fragments of unrolled silicified wood, including Osmunda dowkeri. At a higher level, a short distance below the Corbula Bed which marks the base of the Woolwich Beds, Gardner recorded a second shell-bed marked by an abundance of Arctica morrisi, Astarte tenera, Cucullaea decussata, Gari edvardsi and Glycymeris terebratularis. This is evidently the bed described by Cooper (1934) and is the Astarte tenera Bed of Ward.

The foraminifera of the Thanet Beds have been revised by Haynes (1956–58), Wood and Haynes (1957) and Haynes and El-Naggar (1964). The palaeoenvironmental significance of this work is discussed above (Chapter 5).

The mollusca of the Thanet Beds have been studied by Dr Adrian Rundle who has contributed the following observations.

Dosiniopsis bellovacina, recorded in the literature from the Thanet Beds, is found in the Blackheath and Oldhaven beds. It is more massive than and differs in shape from D. orbicularis (Morris, 1852, p.265, pl. 16, fig. 5), listed here. D. bellovacina ensiformis is not recognised as a distinct taxon.

Two species of Panopea are recorded in the literature from the Thanet Beds. Of these, P. granulata (Morris, 1852, p. 264, p1. 16, fig.3) is here considered a synonym of P. remensis (Mellville, 1843, p. 78); P. intermedia is not found below the Blackheath and Oldhaven beds.

Pseudamusium contubernalis is here treated as a junior synonym of 'Peden' prestwichii. The generic assignment of this species is not yet certain.

Thracia oblata, recorded in the literature from the Thanet Beds, was described from the London Clay of Bognor Regis; the Thanet Beds form is an undescribed species.

The Corbula Bed was noticed by Gardner (loc. cit., p. 204) and may be identified as the lower bed a of Prestwich's table of the cliff east of Bishopstone Glen (Prestwich, 1854). Lithostratigraphically it is most conveniently regarded as the basal bed of the Woolwich Beds and a distinctive litho-logical band of it has been traced over a wide area (see pp. 31, 32, 37); but Wrigley (1949a, p.45) considered the molluscan fauna to be decidedly Thanetian. The bed is crowded with Corbula regulbiensis, generally silicified, and often showing the accessory rostral plate first noticed by Vincent (1909).

The fossils of the Woolwich Beds above the Corbula Bed are not notably interesting in this area, though it is worthy of remark that they are of marine facies in contrast with the estuarine or fluviatile character of the fauna farther west.

White (1931, p. 4) suggested the term 'Bishopstone type' for the marine development of these beds. Gurr (1963) described a fish fauna from a pebbly band seen in the cliffs and foreshore at Herne Bay. He described 25 species (of which two were new) in 17 genera (of which one was new). He concluded that this fauna, which consists mainly of inshore forms, was not directly descended from the northwest European Cretaceous fish fauna, but migrated into the region from elsewhere. The stratigraphical position of this fauna is discussed in Chapter 5 (pp. 31, 37).

The Oldhaven Beds were formerly exposed at Grove Ferry, Chislet (see p.42). G. B. Sowerby's list of species said to come from this section (in Brown, 1859) suggests the presence of extraneous items from the Pliocene and Pleistocene Crags of East Anglia, but many of his identifications are suspect. Whitaker (1866, p. 416) attempted to clarify the list, but was hampered by the loss of part of the collection, and some of his comments are themselves confusing. Kennard and Woodward, (1901, p. 241) and Withers (1953, p. 39) were respectively unable to trace the npnmarine mollusca and cirripedes recorded. The late Mr C. P. Castell searched the John Brown Collection at the British Museum (Natural History), with the aid of Brown's MS notes, and has reassembled all that can now be certainly identified of the 36 items listed by Sowerby. It will probably never be possible to say how many of the remaining anomalies were due to misidentification of Oldhaven Beds fossils and how many to the admixture of extraneous material, but it is probable that some Pleistocene shells came from drift at the site (see p. 77) and possible that derived Pliocene material also occurred (p. 77).

Castell reports that Brown collected at Grove Ferry in 1855–57 and that his collection was bequeathed to Richard Owen, who presented it to the British Museum in 1860. Brown's MS notes include three successively revised and annotated lists of the Grove Ferry fauna, the last differing little from that published (Brown, 1859).

The table on pp. 53 and 54 gives, first the published identification for each species, secondly, an abstract of Whitaker's comments and thirdly, a summary of Castell's report. The registered numbers quoted in the last column are those of the surviving original specimens in the British Museum (Natural History).

The London Clay of Herne Bay comprises the lowest beds of the formation and is readily distinguished palaeontologically from the higher beds exposed in the Isle of Sheppey; it is also much less rich in animal fossils. In 1841 W. Richardson described the locality from which he obtained the skull of Hyracotherium leporinum and mentioned what must have been a raft of vegetation at the same place (Stud Hill, Herne Bay). He also indicated topographic changes due to coast erosion. These have been intensively studied in more recent times (Hutchinson, 1967, 1968) and it has been found (by Mr M. J. Hughes) that the diatom Coscinodiscus and certain foraminifera can be used to locate with precision the slip-planes in the clay along which movement repeatedly occurs (see also p.105). Invertebrate fossils are few because, according to the late A. Wrigley (in litt.), 'the mollusca are all pyritised and thin shells decay rapidly by exposure to the sea air. The only chance of finding good, determinable specimens is to collect on the broken cliff-slopes during winter when fresh material is exposed, but access is difficult, if not dangerous, at this season from the soft state of the slopes'. In dry weather, only indeterminable pyritic casts are found. The commonest forms are fragments of the stem of the crinoid Isselicrinus subbasaltiformis and Thyasira angulata. These, which are not found in the basal 15 m or so of the London Clay, characterise Wrigley's Division 2 of the London Clay in the London area and in Essex (Wrigley, 1924, p. 251; Davis, 1951, pp. 332–334).

The Isle of Sheppey has long been a classical locality for London Clay fossils. According to the late A. G. Davis (personal communication) most of the old collections were probably made around Minster (Sheet 272), but in his 1935 work, and in his own collection, the various localities are differentiated. The accompanying lists have been compiled from those sources with his help and with that of Mr J. Cooper of the British Museum (Natural History).

The London Clay flora was described in a classic monograph by Reid and Chandler (1933). That work was almost confined to material from Sheppey (mainly Minster), but in a more recent revision (Chandler, 1961), many records from Warden Point are given, and a rich flora is described for the first time from Herne Bay. (The flora of the Thanet Beds, Woolwich Beds and Oldhaven Beds is also dealt with in more detail than before.)

In the latest work on the subject Chandler (1964) reviews the Eocene and Oligocene fossil plants of England as a whole. She considers that all belong to a single floristic unit—the Lower Tertiary Flora—and describes the factors, both botanical and non-botanical, that cause the various geological occurrences to differ from each other. The London Clay flora, comprising some 500 species in about 140 genera and 57 families, is by far the most thoroughly studied; but it consists almost entirely of fruits and seeds (though there is unpublished work on the pollen) in an unusual state of preservation. The fossils are completely pyritised, so that soft parts may be represented in detail while carbonaceous matter flakes off and is lost.

Professor W. G. Chaloner comments as follows on fossil wood at Sheppey: 'Wood occurs at Sheppey in three states of preservation. By far the commonest are small twigs, about the thickness of a pencil, preserved as petrifactions in pyrite. These twig fragments must outnumber fruits and seeds by a factor of perhaps as much as a hundred, and are undoubtedly the commonest fossils on the north shore of Sheppey. Larger pieces of 'Teredo'-bored wood, preserved as calcified petrifactions, commonly occur in (or derived from) septarian nodules. Their structure is in some cases quite well preserved.'

'Regrettably, little work has been done on any of this wood material, probably largely because of its association with the extensive (and botanically more informative) fruit and seed flora. However, Scott and de Klerk (1974) give an interesting quantitative analysis of the ratio of conifer twigs to dicotyledonous plants in this Sheppey 'twig flora'. Rather surprisingly, conifer twigs represent one third of the total–a far higher proportion than might be expected in a lowland tropical assemblage (and a very different ratio from that in the fruit and seed flora in which the conifer constituent is negligible). Whether these twigs represent a long-transported element (from either higher altitudes or higher latitudes) or whether they represent a conifer element in a lowland tropical flora without any contemporary equivalent (cf. Daley, 1972) remains unresolved. In any event, the comparison of the pictures presented by the fruit flora, the twigs and the pollen still gives plenty of scope for future palaeoecological study. Leaves and cuticles are not known.'

The flora as we now see it is predominantly a lowland tropical one and most resembles the flora of south-east Asia among Recent floras. Some genera, however, may be montane or extra-tropical (Araucarites, Cantitilia, Cupressinites, Dunstania, Magnolia), and others include both lowland and montane species which cannot, however, be separated from each other on fruit characters alone (Cinnamomum, Juglandicarya, Platycarya, Symplocos). It is reasonable to suppose that the material came from plants growing near watercourses (which floated them down to the sea), with an inevitable bias in favour of those growing alongside the lower reaches. Dr Ma Khin Sein's unpublished work on the pollen, which would have been dispersed by wind as well as water, confirms the presence of a large lowland tropical component in the flora, but also brings out a stronger representation of an upland (or perhaps non-tropical) component. Daley (1972) has reservations on the exact equivalence of the London Clay flora to any present-day counterpart, but bases these on broad palaeoclimatic considerations rather than any revision of the plant fossils themselves.

The accompanying lists have been compiled from Chandler's works of 1961 and 1964 and give only those forms cited as coming from localities within the Faversham Sheet. No inferences, stratigraphical or botanical, should be drawn from the differences between the Herne Bay and Sheppey lists.

The invertebrate fossils of the London Clay, of which the mollusca are by far the most important, have not been comprehensively revised. The fishes, however, have been exhaustively dealt with by Casier (1966) and Stinton (1966).

The London Clay has yielded nearly 140 species of fishes; but the material comes from three largely independent sources. The Elasmobranchs are known mainly from teeth which, in our area, may be collected on the foreshore at Herne Bay and in Sheppey, or in situ in the cliffs. The Osteichthyes are known almost exclusively from skulls preserved with minimal distortion in septarian nodules (whence comes also some elasmobranch material besides teeth); very little is known of other parts of their skeletons. The nodules were once collected by hand and burned to make cement, but apart from the fact that they are commonest in the upper part of the formation and especially around Warden Point, nothing is known of their precise stratigraphical context. Out of 120 or so species known from these two sources, all but half a dozen occur in the eastern part of the Isle of Sheppey.

The third source of fish material consists of otoliths, obtained by washing and sieving large quantities of clay (Stinton, 1966, 1975). Forty-six species are known from Sheppey in this way. Yet only two genera and one species are known from both skull and otoliths; moreover, the otoliths belong mainly to fishes of families not represented by skulls, and there are differences even at subordinal and ordinal level. It is difficult to explain this almost total discrepancy. White (in Casier, 1966, p. v) argues that skulls sufficiently robust to become fossilised in septaria would retain their otoliths; while of those that broke up before fossilisation, the fragile bones would disappear although the more durable otoliths might remain. It may also be argued that a majority of otoliths appear to have come from immature fishes and are found in concentrations that may represent the excreta of predators. Since most predatory fishes are pelagic, especially the sharks, species foreign to the area may have been imported in this way.

The differences just described do not alter the uniformity of the inferences that may be drawn from all three sources of fossil fish material. The fish fauna is a tropical and subtropical one, of neritic to deep-sea habitat, free-swimming and mainly carnivorous (feeding on other fishes or on mollusca). In spite of the rich land flora, there is no sign of any fresh-water element in the fish fauna. Nevertheless the Elasmobranchs and some bony fishes suggest a more littoral environment. A few species strengthen the evidence provided by the occurrence of Arctica and Astarte among the mollusca of cooler conditions at certain times. The lack of stable sections through the London Clay makes it impossible to analyse these minority elements in the environmental conditions of the time, or to relate them to the stratigraphy.

The tables that follow are arranged under the formations as mapped, not under biostratigraphical divisions as such. RVM

Thanet Beds

• A comprehensive faunal list for the Thanet Beds at Herne Bay has recently been published by Ward (1978).

Woolwich Beds

Corbula Bed

• Localities: Herne Bay and Waystreet Farm [= Oakwell], near Goodnestone.

Plantae

• Araceae? genus indet.
• Canticocculus cooperi Cleyera? cooperi
• Canticocculus? stigmosa
• Cocculinae? genus indet.
• Cocculus serratus
• Epacridaceae? genus indet.
• Euphorbiaceae? genus indet.
• Laurocarpum (or Cinnamomum?) sp.
• Laurocarpum spp.
• Natsiatum eocenicum
• Rhamnaceae? sp.
• Symplocos? sp.
• Tempskya sp. [provenance uncertain; see Chandler, 1968]
• Tinospora excavata
• Vitis spp.
• Zanthoxylon? sp.

Animalia

Foraminiferida

• Nodosaria raphanistrum

Porifera

• Stelleta sp.(spicules)

Bryozoa

• Conopeum sp.

Mollusca

Scaphopoda

• Dentalium sp.

Gastropoda

• Aporrhais analogus
• Aporrhais dispar
• Aporrhais triangulata
• Calyptraea suessoniensis
• Epitonium bowerbanki
• Euspira cantiana
• Ficus intermedia
• Hemipleurotoma cf. infraeocenica
• Natica (s.l.) thanetensis
• Sigatica abducta
• Siphonalia mariae
• Thanetinassa bicorona
• Tornatellaea parisiensis

Bivalvia

• Arctica morrisi
• Arctica scutellaria
• Corbula regulbiensis
• Corbula sp.
• Cucullaea decussata
• Cyrtodaria rutupiensis
• Diplodonta sp.
• Dosiniopsis bellovacina
• Gari edvardsi
• Glycymeris plumstediensis
• Glycymeris terebratularis
• Nemocardium (Arctopratulum) plumstedianum
• Nucula fragilis
• Ostrea bellovacina
• Panopea granulata
• Panopea intermedia
• Teredo antenautae
• Thracia oblata

Pisces

Elasmobranchii

• Heterodontus sp.
• Hypolophus farreri
• Hypotodus robustus I
• surus novus
• 'Lamna' inflata
• Lamna obliqua
• Myliobatis sp.
• Notidanodon loozi
• Palaeogaleus vincenti
• Palaeohypotodus rutoti
• Squalus orpiensis
• Squatina prima
• Striatolamia striata
• Synodontaspis teretidens
• Synodontaspis hopei

Chimaeroidea

• Callorhynchus regulbiensis
• Chimaera eophantasma
• Edaphodon minor
• Elasmodus hunteri
• Ischyodus dolloi

Osteichthyes

• Albula oweni
• Ardiodus marriotti
• Egertonia sp.
• Pyenodus sp.

Oldhaven Beds

• Localities: Herne Bay, Bishopstone Glen, Reculver, Grove Ferry, Fostall and two localities near Westbere.

Mollusca

Scaphopoda

• Laevidentalium nitens

Gastropoda

• Acirsa sp.
• Acteon sp.
• Aporrhais triangulata
• 'Buccinum' concinnum
• Bulla sp.
• Euspira bassae
• Euspira cantiana
• Euspira glaucinoides
• Evelynella sp. nov. (cf. Odostomia regularis)
• Ficus eocenica
• Ficus nodulifera
• Hemipleurotoma infraeocenica cf. Parvisipho sp.
• Pollia lata
• Ringicula sp.
• Sigapatella echinulata
• Sigatica abducta
• Siphonalia cooperi
• Siphonalia subnodosa

Bivalvia

• Amygdalum cf. depressum
• Arctica morrisi
• Arctica scutellaria
• Astarte (Ashtarotha) elevata
• Corbicula (Loxoptychodon) cuneiformis
• Corbula regulbiensis
• Corbulasp. nov.(morrisi Edwards MS)
• Cyrtodaria rutupiensis
• Dosiniopsis bellovacina
• Glycymeris plumstediensis
• Leionucula proava
• Miocardiopsis sp. nov.
• Mytilus (Arcomytilus) sp.
• Nemocardium (Arctopratulum) plumstedianum
• Nucula fragilis
• Nucula sextans
• Nucula striatella
• Nucula sp. nov.
• Ostrea sp.
• Panopea intermedia
• Pitaria sp.
• Pterelectroma medium
• 'Teredo' antenautae

Echinodermata

• Ophiura wetherelli

Pisces

Elasmobranchii

• Palaeohypotodus rutoti
• Striatolamia striata
• Synodontaspis teretidens

Chimaeroidea

• Amylodon eocenicus

Osteichthyes (otoliths)

• Albula eppsi
• Ardiodus marriotti
• Argentina abbatinae
• Lactarius curvidorsalis
• Lepophidium subteres
• Microgadus eocenicus
• Palaeogadus pinguis

Osteichthyes

• Bones, teeth, scales and vertebrae

Reptilia

• Chelonian bones

London Clay

(a) Division 2 of Wrigley (1924)

• Localities: Herne Bay (various points), Stud Hill, Swalecliffe

Plantae

Filicales

• Two types of rachis, family indet.
• Gymnospermae
• Pinus macrocephalus?

Monocetyledones

• Nipa burtini
• Palmospermum cooperi
• Palmospermum minutum
• Palmospermum ornatum
• Palmospermum spp.
• Posidonia parisiensis?
• Sabal grandisperma?

Dicotyledones

• Alangium jenkinsi
• Anacardiaceae? genus indet.
• Beckettia mastixioides
• Beilschmiedia oviformis
• Beilschmiedia pyriformis
• Calycocarpum? jenkinsi
• Canticarya ventricosa
• Cantitilia lobata
• Cantitilia polysperma
• Carpolithus gracilis
• Carpolithus thunbergioides
• Carpolithus sp.38 Reid & Chandler
• Carpolithus sp.49 Reid & Chandler
• Carpolithus sp.50 Reid & Chandler
• Carpolithus spp.
• Choerospondias sheppeyensis
• Cinnamomum globulare
• Cinnamomum grande
• Cinnamomum oblongum
• Cinnamomum ovoideum
• Citrispermum sheppeyense
• Cucurbitospermum cooperi
• Cupanoides grandis
• Cupanoides tumidus?
• Dracontomelon minimum
• Dracontomelon subglobosum
• Dunstania ettingshauseni
• Durania stonei
• Erythropalum jenkinsi
• Euphorbiospermurn cooperi
• Euphorbiospermurn eocenicum
• Euphorbiotheca minima
• Hightea elliptica
• Hightea turgida
• Icacinicarya amygdaloidea
• Icacinicarya foveolata
• Icacinicarya minima?
• Icacinicarya nodulifera
• Icacinicarya ovoidea
• Icacinicarya platycarpa
• Icacinicarya reticulata
• Iodes multireticulata
• Iodes? sp.
• Jenkinsella apocynoides
• Juglandicarya cooperi
• Juglandicarya depressa
• Juglandicarya lubbocki?
• Juglandicarya minuta
• Lagenella alata
• Lagenoidea bilocularis
• Lanfrancia subglobosa
• Langtonia bisulcata
• Lannea? sp.
• Laurocalyx globularis
• Laurocarpum cupuliferum
• Laurocarpum minimum
• Laurocarpum minutissimum
• Laurocarpum ovoideum
• Laurocarpum paradoxum
• Laurocarpum sheppeyense
• Laurocarpum sp.16 Reid & Chandler
• Laurocarpum sp.18 Reid & Chandler
• Laurocarpum spp.
• Leguminosae? genus indet.
• Leyrida bilocularis
• Litsea pyriformis
• Lobaticarpum variabile
• Magnolia angusta
• Magnolia crassa
• Magnolia oblongs
• Magnolia rugosa
• Magnolia subcircularis
• Mastixia cantiensis
• Mastixia parva
• Meliosma cantiensis
• Meliosma jenkinsi
• Moraceae? general indet.
• Morus? sp.
• Neuroraphe obovatum
• Nyssa bilocularis
• Oncoba variabilis
• Palaeallophylus minimus
• Palaeallophylus rotundatus
• Palaeobruguiera elongata
• Palaeobruguiera lata
• Palaeonyssa multilocularis
• Palaeophytocrene foveolata
• Palaeovitis paradoxa
• Platycarya richardsoni
• Polycarpella caespitosa
• Portnallia sheppeyensis
• Pseudosclerocarya lentiformis
• Saxifragispermum spinosissimum
• Sapindospermum cooperi
• Sapindospermum jenkinsi
• Sapindospermum revolutum
• Sapindospermum sp.
• Sphinxia ovalis
• Talauma wilkinsoni
• Tamesicarpum polyspermum
• Tetracera crofti
• Tetracera eocenica
• Tinomiscium taylori
• Tinospora excavata
• Tinospora wilkinsoni
• Wetherellia variabilis

Animalia

Foraminiferida

• Cornuspira involvens
• Miliolina seminudum
• Miliolina venusta
• Nodosaria hispida
• Spiroloculina sp.

Porifera

• Stelleta sp.
• Hydrozoa
• Graphularia wetherelli

Annelida

• Ditrupa plana

Mollusca

Scaphopoda

• Laevidentalium anceps

Gastropoda

• 'Cassis' striata
• Scaphella wetherelli

Bivalvia

• Cuspidaria injlata
• Nuculana amygdaloides
• Nuculana partimstriata
• Pecten duplicatus
• Thyasira angulata

Cephalopoda

• Eutrephoceras regale

Echinodermata

• Isselicrinus subbasaltiformis

Pisces

Elasmobranchii

• Hypotodus verticalis Lamna obliqua
• Striatolamia macrota
• Synodontaspis hopei
• Palaeohypotodus rutoti in Basement Bed, probably derived
• Synodontaspis teretidens in Basement Bed, probably derived

Chimaeroidea

• Elasmodus hunteri
• Osteichthyes
• Eutrichiurides winkleri
• Phyllodus toliapicus
• Rhinocephalus planiceps
• Xiphiorhynchus sp.

Mammalia

• Hyracotherium leporinum
• Platychaerops richardsoni

(b) Upper London Clay

• Localities: Isle of Sheppey (eastern part)

Plantae

Gymnospermae

• Araucarites? sp.
• Cupressinites oviformis
• Pinus macrocephalus?

Monocotyledones

• Nipa burtini
• Palmospermum davisi
• Palmospermum elegans
• Palmospermum ovale
• Palmospermum pulchrum
• Palmospermum sp.
• Posidonia parisiensis?
• Sabal sp. (grandisperma?)

Dicotyledones

• Anacardiaceae? genus indet.
• Anonaspermum anon forme
• Anonaspermum commune
• Anonaspermum complanatum
• Anonaspermum complicatum
• Anonaspermum ovale
• Anonaspermum pulchrum?
• Anonaspermum sp.
• Beilschmiedia oviformis
• Canticarya sheppeyensis
• Cantitilia lobata
• Cantitilia polysperma
• Carpolithus pusillus var. latus
• Carpolithus scalarfformis
• Carpolithus sp.34 Reid & Chandler
• Carpolithus sp.49 Reid & Chandler
• Carpolithus spp.
• Caxtonia elongata
• Caxtonia glandulosa
• Cinnamomum globulare
• Cinnamomum oblongum
• Citrispermum sheppeyense
• Cucurbitospermum sheppeyense
• Davisicarpum gibbosum
• Dracontomelon subglobosum
• Dunstania multilocularis
• Erythropalum europaeum?
• Erythropalum turbinatum
• Euphorbiospermum obliquum
• Euphorbiospermum subovoideum
• Euphorbiospermum? sp.
• Faboidea crassicutis Icacinaceae? genus indet.
• Icacinicarya echinata
• Icacinicarya forbesi
• Icacinicarya foveolata
• Icacinicarya glabra
• Icacinicarya sp.(nodulifera?) lodes corniculata
• Icacinicarya multireticulata
• Juglandicarya minuta
• Lagenella alata
• Lagenoidea bilocularis
• Lagenoidea trilocularis
• Lanfrancia subglobosa
• Langtonia bisulcata
• Lannea jenkinsi
• Laurocarpum davisi
• Laurocarpum minimum
• Laurocarpum sp.16 Reid & Chandler
• Laurocarpum (Endiandra?) sp.
• Leguminocarpon nervosum
• Leguminosae? genus indet.
• Leucopogon quadrilocularis
• Magnolia angusta
• Magnolia crassa
• Magnolia davisi
• Magnolia enormis
• Magnolia gigantea
• Magnolia lobata
• Magnolia oblonga
• Magnolia pygmaea
• Magnolia rugosa
• Magnolia subcircularis
• Magnolia sub quandrangularis
• Magnolia subtriangularis
• Magnolia symmetrica
• Mastixia parva
• Mastixia? sp.
• Meliosma jenkinsi?
• Nyssa bilocularis
• Nyssa spp.
• Oncoba variabilis
• Palaealectryon spirale
• Palaeophytocrene foveolata
• Palaeovitis paradoxa
• Parthenocissus jenkinsi
• Parthenocissus monasteriensis
• Portnallia bognorensis
• Protoravensara sheppeyensis
• Rhizophoraceae? genus indet.
• Sapindospermum davisi
• Sapindospermum sp.
• Symplocos trilocularis
• Symplocos sp.
• Tetracera eocenica
• Tetrastigma davisi
• Tetrastigma elliotti
• Tetrastigma sheppeyensis
• Tinomiscoidea scaphiformis
• Tinsopora excavata
• Vitis bilobata
• Vitis bracknellensis
• Vitis elegans
• Vitis longisulcata
• Vitis platyformis
• Vitis rectisulcata
• Vitis semenlabruscoides
• Vitis subglobosa
• Wardenia davisi

Animalia

Anthozoa

• Paracyathus caryophyllus
• Platycyathus brevis

Annelida

• Ditrupa plana
• Granularia sp.
• Protula spp.
• Rotularia bognoriensis
• Serpula trilineata
• Hooklets of parasitic worms

Bryozoa

• Adeonellopsis wetherelli
• Batopora clithridiata
• 'Cribrilina' sp.
• Didymosella sp. nov.
• Dittosaria wetherelli
• Entalophora sp.
• Idmonea sp.
• Lunulites sp.
• Nellia sp.
• Pachythecella incisa
• Vibracellina sp.
• Websteria crissioides

Brachiopoda

• Lingula tenuis
• Terebratulina wardenensis

Mollusca

Scaphopoda

• Laevidentalium anceps

Pteropoda

• Camptoceratops prisca
• Spiratella mercinensis
• Spiratella tutelina

Gastropoda

• Aporrhais sowerbii
• Athleta nodosus
• Bartonia curta
• Bathytoma granata
• Bonellitia laeviuscula
• Calyptraea sp.
• 'Cassis' striata
• Conospirus concinnus
• Crenilabium elongatum
• ?Cyrtochetus sp.
• Eocypraea oviformis
• Eotibia lucida
• Euspira glaucinoides
• Euthriofusus complanatus
• Euthriofusus transversarius
• Ficopsis multiformis
• Foratiscala sp. nov.(perforata Edwards MS)
• Fusinus unicarinatus
• 'Fusinus' wetherelli
• Hemipleurotoma fasciolata
• Hemipleurotoma konincki
• Hemipleurotoma selysi
• Hemipleurotoma wetherelli
• 'Litiopa' sp. nov. (sukulosa Edwards MS)
• Murex argillaceus
• Orthochetus elongatus
• 'Patella' sp.
• Pseudotoma topleyi
• Ptychatractus aff. interruptus
• Roxania? sp.
• Sassia morrisi
• Scaphander? parisiensis
• Scaphella wetherelli
• Sinum clathratum
• Siphonalia highgatensis
• Stellaxis pulcher
• 'Streptolathyrus' trilineatus
• Streptolathyrus zonulatus
• Surculites errans
• Surculites sp. nov.(velatus Edwards MS)
• Tornatellaea aff. simulata
• Trochotugurium extensum
• Turbonilla subterranea
• Turricula crassa
• Turricula symmetrica
• Turricula teretrium nanodis

Bivalvia

• Abra splendens
• Amygdalum depressum
• Arctica planata
• Astarte filigera
• Astarte rugata
• Astarte sp. nov.
• Calpitaria sulcataria
• Cuspidaria inflata
• Lentipecten corneus
• Nemocardium nitens
• Nuculana amygdaloides
• Pecten sp.
• Pinna affinis
• Pterelectroma medium
• Pteria papyracea
• Pycnodonte gryphovicina
• Striarca? wrigleyi
• 'Teredo' spp.
• Teredo (Nausitora) sp.
• Thyasira goodhalli
• Verticordia sulcata

Cephalopoda

• Aturia ziczac
• Belopterina levesquei
• Belosepia blainvillei
• Cimomia imperialis
• Deltoidonautilus sowerbyi
• 'Eutrephoceras' centrale

Crustacea

Malacostraca

• Dromilites lamarcki
• Hoploparia gammaroides
• Glyphithyreus [Plagiolophus] wetherelli
• Zanthopsis leachi

Cirripedia

• Scalpellum minutum
• Scalpellum quadratum

Ostracoda

• Cythere scabropapulosa
• Cythereis bowerbanki
• Cythereis spiniferrima
• Cytherella compressa
• Cytheropteron triangulare

Echinodermata

• Democrinus londinensis
• Coulonia colei
• Teichaster stokesi
• Coelopleurus wetherelli
• Schizaster sp.
• Trochostoma sp.

Pisces

Elasmobranchii (mainly teeth)

• Aetobatus irregularis
• Anomotodon sheppeyensis
• Burnhamia daviesi
• Dasyatis davisi
• Galeorhinus lefevrei
• Galeorhinus minor
• Galeorhinus sp.
• Heterodontus vincenti
• Heterodontus wardenensis
• Heterodontus sp.
• Hypoprion sp.
• Hypotodus robusta
• Hypotodus verticalis
• Isistius trituratus
• Isurolamna affinis
• Isurus praecursor
• Jaekelotodus trigonalis
• Lamna lerichei
• Lamna obliqua
• Myliobatis dixoni
• Myliobatis latidens
• Myliobatis toliapicus
• Notorhynchus serratissimus
• Odontaspis sp.
• Physodon tertius
• Raja sp.
• Rhinobatos sp.
• Scyliorhinus biauriculatus
• Scyliorhinus casieri
• Scyliorhinus mintuissimus
• Scyliorhinus pattersoni
• Squalus minor
• Squatina prima
• Striatolamia macrota
• Synodontaspis hopei
• Synodontaspis winkleri
• Xenodolamia eocaena

Osteichthyes (mainly skulls)

• Acestrus elongatus
• Acestrus ornatus
• Acipenser toliapicus
• Aglyptorhynchus sulcatus
• Aglyptorhynchus venablesi
• Albula oweni
• Ampheristus toliapicus
• ?Ardiodus marriotti
• ?Argillichthys toombsi
• Aulopopsis depressifrons
• Aulopopsis egertoni
• Beerichthys ingens
• Beerichthys? sp.
• Bramoides brieni
• Brychaetus muelleri
• Bucklandium diluvii
• Cybium cf. proosti
• Cylindracanthus rectus
• Egertonia isodonta
• Elops sp.
• Enniskillenus radiatus
• Eocoelopoma colei
• Eocoelopoma gigas
• Eocoelopoma hopwoodi
• Eothynnus salmoneus
• Esocelops cavifrons
• Eutrichiurides winkleri
• Goniocranion arambourgi
• Halecopsis insignis
• Hemirhabdorhynchus elliotti
• Labrophagus esocinus
• Laparon alticeps
• Lehmanamia sheppeyensis
• Megalops oblongus
• Megalops priscus
• 'Myripristis toliapicus'
• Naupygus bucklandi
• Paraberyx bowerbanki
• Percostoma angustum
• Phyllodus toliapicus
• Plesioserranus cf. wemmeliensis
• Podocephalus curryi
• Podocephalus nitidus
• Progempylus edwardsi
• Promegalops signeuxae
• Promegalops sheppeyensis
• Pseudosphaerodon antiquus
• Pycnodus bowerbanki
• Pycnodus toliapicus
• Pycnodus sp.
• Rhinocephalus planiceps
• Rhynchorhinus branchialis
• Rhynchorhinus major
• Sciaenurus bowerbanki
• Sciaenurus bowerbanki f. crassior
• Sciaenuropsis turneri
• Scombramphodon crassidens
• Scombramphodon sheppeyensis
• Scombrinus macropomus S. nuchalis
• Serranopsis londinensis
• Sphyraenodus priscus
• Tamesichthys decipiens
• Teratichthys antiquitatis
• Trichiurides sagittidens
• Wetherellus brevior
• Wetherellus cristatus
• Wetherellus longior
• Whitephippus tamesis
• Whitephippus sp.
• Woodwardella patellifrons
• Xiphiorhynchus priscus
• Xiphiorhynchus parvus

Osteichthyes (otoliths)

• Agonus? rugatus
• Amanses sulcifer
• Ampheristus toliapicus
• Apogon glaber
• Argentina extenuata
• Bothus decipiens
• Brosmophycis sagittalis
• Brotula arcuata
• Centroberyx lemoinei
• Centropomus excavatus
• Cephalopholis striatus
• Cepola densa
• Cirrhitus radians
• Citharichthys varians
• Dermatopis argutus
• ?Diplomystes rudis
• Ditrema sheppeyensis
• Embiotoca conjugens
• Epinephelus ovalis
• Enophrys euglyphus
• Etelinus ostiolatus
• Eucitharus circularis
• Gnathophis circularis
• Holocentrus sheppeyensis
• Hypomesus pennatus
• Leuresthes distans
• Lutianus gracilis
• Maena rectangulus
• Microgadus subnotus
• Muraenesox cymbium
• Nemopteryx serratus
• Neobythites obtusus
• Paralabrax tenuicauda
• Peristedion semiglobosum
• Pterothrissus angulatus
• Pterygotrigla londinensis
• Raniceps papillosus
• Scomberomorus priscus
• Sebastodes bognoriensis
• Selachophidium splendens
• Spicara minsterensis
• Synanceia undata
• Synodus bisectus
• Synodus davisi
• Trachichthodes lemoinei
• Uroconger validus
• Xenistius aculeatus
• Xiphiurus angustus
• Zaniolepis acutus

Reptilia

Chelonian bones

• Crocodilus spenceri
• Lytoloma longiceps
• Palaeophis toliapicus

Aves

• Leg-bones of a gallinaceous bird

Mammalia

• Argillotherium toliapicum
• Coryphodon eocaenus
• Hyracotherium leporinum

References

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BROWN, J. 1859. On the occurrence of some Tertiary fossils at Grove Ferry, near Canterbury, Kent. With descriptions of some of the species by G. B. Sowerby. Q. J. Geol. Soc. London, Vol. 15, pp. 133–135.

CARRUTHERS, W. 1870. On the structure of a fern-stem from the Lower Eocene of Herne Bay, and on its allies, Recent and fossil. Q. J. Geol. Soc. London, Vol. 26, pp. 349–354, pls. 24,25.

CASTER, E. 1966. Faune ichthyologique du London Clay. xiv 496 pp., Atlas 65 pls. (London: British Museum (Natural History).)

CHANDLER, M. E. J. 1961. The Lower Tertiary floras of southern England. I. Palaeocene floras. London Clay flora' (Supplement). xii + 354 pp. Atlas 34 pls. (London: British Museum (Natural History).)

CHANDLER, M. E. J. 1964. The Lower Tertiary floras of southern England. IV. A summary and survey of findings in the light of recent botanical observations. xii + 152 pp., 4 pls. (London: British Museum (Natural History).)

CHANDLER, M. E. J. 1968. A new Tempskya from Kent. Bull. Brit. Mus. (Nat. Hist.) (Geol.), Vol. 15 (4), pp. 171–179.

COOPER, J. E. 1934. Oldhaven and Thanet Sand Mollusca of Herne Bay. J. Conch., Vol. 20, pp. 4–8.

CURRY, D. 1965. The English Palaeogene Pteropods. Proc. Malac. Soc. London, Vol. 36, pp. 357–371.

DAVIS, A. G. 1936. The London Clay of Sheppey and the location of its fossils. Proc. Geol. Assoc., Vol. 47, pp. 328–345. – 1937. Additional notes on the geology of Sheppey. Proc. Geol. Assoc., Vol. 48, pp. 77–78.

DAVIS, A. G. and ELLIOTT, G. F. 1951. The London Clay of coastal Suffolk and Essex. Geol. Mag., Vol. 88, pp. 329–338.

DALEY, B. 1972. Some problems concerning the early Tertiary climate of southern Britain. Palaeogeog. Palaeoclimatol., Palaeoecol., Vol. 11 (3), pp. 177–190.

FARCHAD. H. 1936. Etude du Thanetien (Landenien marin) du basin de Paris. Mem. Soc. Geol. Fr., N.S., Vol. 13, No. 30.

GARDNER, J. S. 1883. On the Lower Eocene section between Reculvers and Herne Bay, and on some modifications in the classification of the Lower London Tertiaries. Q. J. Geol. Soc. London, Vol. 39, pp. 197–210.

GURR, P. R. 1963. A new fish fauna from the Woolwich Bottom Bed (Sparnacian) of Herne Bay, Kent. Proc. Geol. Assoc., Vol. 73, pp. 419–447.

HAYNES, J. 1956–58. Certain smaller British Palaeocene Foraminifera. Part I, Contrib. Cushman Found, Foram. Res., Vol. 7, pp. 79–101, 1956; Part II, ibid., pp. 4–16, 1958; Part IV, ibid. 9, pp. 58–77; Part V, ibid. 9, pp. 83–92,1958.

HAYNES, J. and EL-NAGGAR, S. R. M. 1964. Reworked Upper Cretaceous and Danian planktonic Foraminifera in the type Thanetian. Micropalaeontology, Vol. 10, pp. 354–356.

HUTCHINSON, J. N. 1967. The free degradation of London Clay cliffs. Proc. Geotech. Conf. Oslo (1967), Vol. 1, pp. 113–118.

HUTCHINSON, J. N. 1968. Field meeting on the coastal landslides of Kent. Proc. Geol. Assoc., Vol. 79, pp. 227–238.

KENNARD, A. S. and WOODWARD, B. B. 1902. The post-Pliocene non-marine Mollusca of the south of England. Proc. Geol. Assoc., Vol. 17, pp. 213–260.

MELLEVILLE, 1843. Memoires sur les sables tertiares inferieurs du bassin de Paris, avec la description de 78 especes de coquilles fossiles inedites de ce terrain. Ann. Sci. Vol. 2, pp. 1–29.

MORRIS, J. 1852. Description of some fossil shells from the Lower Thanet Sands. Q. J. Geol. Soc. London, Vol. 8, pp. 264–267, p1.16.

NEWTON, R. B. 1891. Systematic list of the Frederick E. Edwards collection of British Eocene and Oligocene Mollusca. (London: British Museum (Natural History).)

PRESTWICH, J. 1852. On the structure of the strata between the London Clay and the Chalk in the London and Hampshire Tertiary Systems. Part III The Thanet Sands. Q. J. Geol. Soc. London, Vol. 8, pp. 235–268, pls. 15,16.

PRESTWICH, J. 1854. Part II The Woolwich and Reading Series. Q. J. Geol. Soc. London, Vol. 10, pp. 75–170, pls. i-iv.

REID, E. M. and CHANDLER, M. E. J. 1933. The London Clay Flora. (London: British Museum (Natural History).)

RICHARDSON, W. 1841. Observations on the locality of the Hyracotherium. Trans Geol. Soc. London, Series 2, Vol. 6, pp. 211–214.

STINTON, F. C. 1965. Teleost otoliths from the Lower London Tertiaries. Senckenbergische Lethaea, Vol. 46a, pp. 389–425, pls. 30–33.

TREMLETT, W. E. 1950. English Eocene and Oligocene Cardiidae. Proc. Malac. Soc., Vol. 28, pp. 115–133, pls. 15–19.

TREMLETT, W. E. 1953. English Eocene and Oligocene Veneridae. Proc. Malac. Soc., Vol. 30, Part I, pp. 1–21, pls. 1–4; Part II, pp. 55–71, pls. 9–13.

VINCENT, E. 1909. Presence d'une plaque siphonale chez Corbula regulbiensis Morr. Ann. Soc. roy. tool. et malac. Beige, Vol. 44, pp. 140–142.

WARD, D. J. 1973. The English Palaeogene chimaeroid fishes. Proc. Geol. Assoc., Vol. 84, pp. 315–330.

WARD, D. J. 1978. The Lower London Tertiary (Palaeocene) succession of Herne Bay, Kent. Rep. Inst. Geol. Sci., No. 78/10.

WHITAKER, W. 1866. On the 'Lower London Tertiaries' of Kent. Q. J. Geol. Soc. London, Vol. 22, pp. 404–435. – 1872. The geology of the London Basin. Mem. Geol. Surv. G.B.

WHITE, E. I. 1931. The vertebrate faunas of the English Eocene. (London: British Museum (Natural History).)

WITHERS, T. H. 1953. The Catalogue of Fossil Cirripedia in the Department of Geology, Vol. 3, Tertiary. (London: British Museum (Natural History).)

WOOD, A. and HAYNES, J. 1957. Certain smaller British Paleocene Foraminifera. Contrib. Cushman Found. Foram. Res., Part II, Vol. 8, pp. 45–53.

WOOD, S. V. JR. 1871. A monograph of the Eocene bivalves of England. Palaeontogr. Soc., Vol. I, Part 3, pp. 137–182, pls. 21–25.

WRIGLEY, A. 1924. Faunal Divisions of the London Clay illustrated by some exposures near London. Proc. Geol. Assoc., Vol. 35, pp. 245–249.

WRIGLEY, A. 1929. Notes on English Eocene Mollusca, with descriptions of new species. III. Proc. Malac. Soc., Vol. 18, pp. 235–251, pls. 15,16.

WRIGLEY, A. 1938. English Eocene and Oligocene Strombidae and Aporrhaidae. Proc. Malac. Soc., Vol. 23, pp. 61–88, pls. 4–6.

WRIGLEY, A. 1949a. The Thanet Sands. S.E. Naturalist, Vol. 44, pp. 41–46.

WRIGLEY, A. 1949b. English Eocene and Oligocene Naticidae. Proc. Malac. Soc., Vol. 28, pp. 10–30.

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Chapter 8 Pleistocene and Recent

Introduction

As in the neighbouring Chatham area (Sheet 272), the Drift may be divided almost entirely into two main groups, Head Deposits and River Deposits. The latter are made up of gravels, in three terraced divisions, and alluvium. The former comprise gravels, brickearths, stony loam and rubble of crudely stratified or structureless type, which are usually found mantling hills and valleys alike, or in dissected irregular spreads, or unevenly festooned and channelled into the solid formations on which they rest.

The Head and River Deposits of the present area are intimately connected in their field relationships. Whereas the terraced River Gravels may be grouped in the time-scale mainly according to their relative heights (numbered from the lowest upwards), for the Head Deposits such criteria can be applied only to a limited degree. Nevertheless, the amount of field and faunal evidence that is available in the Faversham area has enabled the whole of the drifts to be placed in a tentative chronological sequence. In this account the Head Deposits have been grouped into four stages, numbered from the oldest onwards; the Head Gravels are divided into an Older, Intermediate and Younger group, with Head Brickearth which appears to correspond with each stage, usually succeeding the gravel in the time-scale. Of the Brickearths the most important and distinctive deposit is the third and youngest, but the associated Younger Head Gravels are in this instance intermingled with it to a considerable extent. The Intermediate Head Gravels show more evidence of fluviatile modes of accumulation locally than do the other groups, and it is probable that they may include in the south-east some gravels of an early stage in the development of the River Stour which are equivalent to those of the upper and middle subdivisions of the Third Terrace as distinguished on the Canterbury (289) Sheet (Smart and others, 1966, pp. 245– 246). Erosion on the high slopes of the northern Blean was probably under frozen-ground conditions modified on the south at the primitive Stour valley; some of the older Head Gravels are the approximate periglacial coevals of Fourth Terrace gravels of the Canterbury area. Younger Head Gravels overlie or grade into gravels of the Second Terrace of the Stour near Stodmarsh and Preston. The Hillwash Head is a local accumulation of stony loam and rubble either collected on or derived from existing hill-slopes.

The sequence and interrelations of these superficial deposits of north-east Kent have been summarised by Holmes (1971, pp. 167–169, figs. 1, 2) from which account the table on p.63 is drawn.

The incidence of the 1st Stage and 2nd Stage Head Brickearths in the Blean but not in the Chatham area suggests early climatic differentiation in near-coastal northeast Kent.

An attempt to relate the above sequence of drifts to described human implement cultures suggests that early Clactonian and early Acheulian industries appeared at the 2nd Stage and Levalloisian became established by the Third Terrace. The extensive Head deposits of the 3rd Stage include implements derived from earlier periods and themselves range from Levallois to Neolithic.

The Head Gravels are considered to be of periglacial origin; they probably represent three major cold stages and their related subsequent Head Brickearths appear to indicate generally increasing aridity and amelioration of the climate (cf. White, 1928, p. 63); in the case of the Younger Head Gravels and the closely associated Head Brickearth greater intermingling of the two types suggests minor climatic oscillations; each main cold period may correspond to a European ice-advance, the deposits of Stage 3 probably reflecting the complex last phases; the course of the main river-drainage was firmly established after the 2nd Stage.

Though the succession of Head Gravels in the Faversham district suggests some parallel with the last three of the four Alpine glacifluvial gravel stages of Penck and Bruckner as adopted by Zeuner (1958, pp. 116–118, 132–134) it is necessary to use caution in looking for possible correlation and in particular to consider the special importance of organic interglacial deposits in relative dating (see, for example, West, 1963, pp. 165–167). Thus a deposit of Second Terrace sands with a distinctive molluscan fauna has provided definitive evidence (see below, p. 63) in formulating the table of sequence.

Consideration given to analogous problems on the drifts studied in great detail in the Somme Valley and elsewhere by Breuil (1934, p. 270; 1939, p. 33) has to be modified in the knowledge that a detailed appraisal of the evidence from human artifacts is not feasible without a modern revision of their typology. It must be recognised in any case, however, that implements found within a deposit probably most frequently derive from a land surface which may antedate by a considerable time the age of formation of that deposit. The late M. l'Abbe Breuil recognised not only evidences of former land surfaces represented by red clays, humic and weathered layers and discontinuities within the drift deposits, but also several subdivisions, e.g. in one series in one particular section, held to represent solifluction deposits corresponding with European glacial phases. He has given detailed sections of the Stour gravels (1934, figs. 23, 24) which refer to deposits of the Third Terrace, where conspicuously cross-bedded gravels and sands are overlain by well developed Head Brickearths and Gravels of the 3rd Stage (see pp. 74–76). Although conforming with the general principles of a sequence, not only of fluviatile deposits, but also of solifluction stages which produced gravels followed by loess-like brickearths, the succession of Drifts in the Faversham area points rather to a broader interpretation of the time-scale than Breuil has implied. If there is little doubt that the Head of Stage 3 reflects the last glaciation (Warm, Weichsel), in a general way, it is doubtful if a preceding glaciation is indicated at any stage later than the Stage 2 of the Head Deposits which probably witnessed the earliest development of a primitive Stour. From the evidence of implements, as then interpreted, Dewey (1925, p. 281) concluded that these 'Upper Terrace gravels of "Sturry" are later than the 100-foot terrace of the Thames at Swanscombe', but there are reasons for supposing that they may in fact be roughly equivalent in age to that terrace, though it would appear that no major glaciation closely followed it (e.g. see King and Oakley, 1936, p.61; Bull, 1942, p. 11, pl. 1). It is probable, on the other hand, that the parts of the Younger Head Gravels which antedate the First Terrace deposits may be assigned to the same general stratigraphical position accorded to those Coombe Deposits (including Coombe Rock) of the Dartford district (Dewey and others, 1924, p. 106) that immediately 'preceded the formation of the Low Te'rrace'. That the last glaciation in Europe (and probably others) consisted of a number of cold and warmer phases has for sometime been recognised (e.g. see Zeuner, 1958, pp. 116, 133) and its onset may be reflected in these earliest of the last group of predominantly periglacial deposits.

As has also been pointed out by West (1963, p. 165), attempts merely to correlate British Quaternary deposits among themselves are hampered by the lack of a detailed Drift map which is continuous and complete, though many isolated exposures have been studied in great detail. Valuable summaries of Pleistocene chronology have been given by King (1955, pp. 187–208) and by Bull (1942, pp. 1–45). King (1955, p. 205) considered that 'there is evidence of two glacial advances in East Anglia and the lower Thames basin prior to the deposition of the Swanscombe gravels…'. Among the many comments in the discussion on Bull's account are some suggestions that similarly admit the possibility that both the Boyn Hill and Taplow terraces of the Thames may fall within the last interglacial. Arkell (1951, p. 17), from evidence which includes work in France, challenged the validity of Breuil's detailed application of the continental sequence to Britain (e.g. Breuil, 1932, pp. 6, 8) and in discussing an account by Woldstedt (1950, p. 621) was able to propose a revised correlation table in which the Boyn Hill and later deposits of the Thames may indeed be interpreted as all of them post-dating the Riss (3rd European) glaciation. The implication that the last interglacial period and its succeeding Warm (=Weichsel) glacial and interstadial phases saw the development of the bulk of the Thames terrace deposits finds supporting evidence from the sequence of Stour drifts, which similarly appears to indicate a long period of river development in the last interglacial.

Correlation of the deposits of the Stour with those of the Medway and the Thames has been facilitated by the discovery of fossiliferous sands overlying gravel of the Second Terrace of the Stour near Preston (p. 77). A suite of mollusca from these deposits includes Corbicula fluminalis, also recorded from two localities near Chislet, and Pisidium astartoides, forms reported by Dr J. W. Jackson as not known later than the Crayford stage of the Thames river-system. Records of Hydrobia radigueli from Second Terrace deposits at the two Chislet localities, Wear Farm and Grove Ferry (pp. 77–78) confirm this, for that shell also made its latest appearance in England at this stage. The Crayford Brickearths have been exhaustively studied for many years and the results were summarised by Kennard (1944, p. 121) in a paper which considers very carefully the evidence on relative age and conditions of deposition afforded by the molluscan and vertebrate faunas and the flint implements. The deposits rest on gravel of the Taplow Terrace (2nd Terrace of the Thames) but also overlap on to older beds, including Thanet Beds and Chalk, usually disturbed and reconstructed (Dewey and others, 1924, p. 100). The molluscan fauna of the fossiliferous sands at Preston is comparable with that of the Lower Brickearth and Corbicula Bed at Crayford and the beds occupy a similar strati-graphical position; in both cases they are overlain discontinuously by a heavier-textured brickearth of Head origin sludged across them from higher ground. Although there was probably erosion and a long interval of time preceding the deposition of the Head at both localities, the shelly sands at Preston are evidently part of the same series as the underlying gravel and there are reasons for supposing that in fact the Lower Brickearth at Crayford succeeded the gravel without a marked break; for not only was the brickearth there seen locally to be interbedded at the base with the gravel (Tylor, 1869, p. 92; Dewey and others, 1924, p. 100) but also two Levalloisian working 'floors' recorded at the base of the brickearth (see Chandler, 1916, p. 242) both appear to be related to a pre-brickearth Chalk surface, which probably remained uncovered by drift until a later date, rather than to a former land surface on the Taplow Terrace gravel (cf. Kennard, 1944, pp. 140, 160). On this view it would appear that, reinterpreting the conclusions of Bull (1942, pp. 15, 44), only the Upper Brickearth at Crayford, with the corresponding deposit at Preston, would be related to the last glaciation in Europe.

It follows that there is evidence to equate approximately the three terraces of the Stour with the Boyn Hill, Taplow and Flood Plain terraces as originally described for the Thames; further, that all three terraces may fall into an interglacial period which culminated in the effects of the last glaciation. The intermediate Head Gravels of the Faversham district have provided another point of correlation with the Thames Valley, for they can be placed in the above scheme as the result of revised views on the typology of the human artifacts which equivalent deposits contain at a site above Fordwich, on the Canterbury (289) Sheet, southward of Sturry (Smith, 1933, p. 165; Coleman, 1952, p. 76). There a reported Abbevillian–Early Acheulian assemblage has been compared by Arkell and Oakley (1948, pp. 152, 153) with a closely studied suite of implements from ancient gravels in the Caversham and Henley area of Oxfordshire, which these authors consider to have a striking affinity 'with the cultures of the pre-Boyn Hill, high-level gravels of Fordwich and Farnham'.

In comparing the sequence of Quaternary deposits with those of the neighbouring Chatham district (Dines, Holmes and Robbie, 1971; see especially pp. 103, 137) it should be noted that the oldest Head deposit in that area, the Claywith-flints, is not represented in the Faversham district; but it is to be found overlying the Chalk on the adjacent high ground to the south and east. It is important as indicating a cold stage (the oldest Head noted by Dines and others, 1940, p. 218) earlier than the Older Head Gravels; much of it is probably of periglacial even if not glacial origin, as formerly claimed by Sherlock and Noble (1912, p. 199) for an area north of the Thames, and the loams and local brickearths in places preserved with it perhaps resemble a subsequent climatically milder Head Brickearth stage.

When the Chatham area was surveyed the evidence for dating the Head Deposits of the Older Group was not entirely clear, though it was recognised that gravels of several ages might be included in the group.

The main 3rd Terrace gravels at Frindsbury include deposits with Acheulian implements; these gravels may be early enough to match the Boyn Hill Terrace of the Thames (Dines, Holmes and Robbie, 1971, pp. 137–138).

Shells and bones from brickearth and head at Halling, in the Medway Valley, show significant points of comparison with the fauna of late Pleistocene non-marine mollusca and mammals from Head Brickearth of the 3rd Stage at Swalecliffe (see pp. 90–91).

In Head Brickearth of both Chatham and Faversham areas, artifacts that include late Acheulian and some Levalloisian types found in the basal parts of the later deposits appear to derive from pre-existing land surfaces. The Head Brickearth at Halling (Cook and Killick, 1924, p. 152) is now, moreover, known to have yielded flint flakes of an age as recent as probable Early Mesolithic (Oakley, K.P. in Kerney, 1963, pp. 250–251); both these and the presence of fire hearths indicate a significant land surface about that time and confirm the hillwash origin of the deposit containing its soils (Dines, Holmes and Robbie, 1971, p. 115).

Kerney (1965, pp. 269–274) has described Weichselian deposits in the Isle of Thanet where 'a stratigraphical sequence earlier than the late-glacial period can be established'. Thus Kerney assigns brickearths at Pegwell Bay and Broadstairs to Middle Weichselian. He also tables the whole solifluction, loessic and chalk detritus deposits for East Kent, ranging them from 50 000 to 10 300 years BP on the radiocarbon dating scale. The brickearths and loams of the western end of the Isle of Thanet must mainly lie within this range and they are generally comparable with the 3rd Stage Head Brickearth in most of the Faversham Sheet area.

Three terraces of River Gravels are indicated on the Faversham (273) Sheet by graded depth of colour in the conventional manner, but the spreads of gravel are considerably obscured by the extensive development of Head Brickearth. Three types of Head Deposits are indicated on the map. The lithological types Head Gravel and Head Brickearth are distinguished by separate colours, without, however, further subdivision into the three stages described above; recent Hillwash Head of the 4th Stage, indicated by a sepia colour, is of relatively little importance in the Faversham area.

There is little direct information to indicate the age of the Alluvium. A great deal of this deposit has evidently been laid down by present-day streams, but some may be partly marine or estuarine and considerably older, for example, where the Swale merges into the Thames Estuary. On the other hand, recent marine silts will occur in the Wantsum Channel, where marshes now border the Isle of Thanet, for an arm of the sea occupied this region until historic time (see p.93). Salt marshes are characteristic of the areas liable to flooding and may carry on them a thin deposit of recent marine alluvium.

Blown sand and shelly shingle, still in the process of accumulation at Warden and Shell Ness in the Isle of Sheppey, are together sufficiently extensive to be shown as a separate deposit on the geological map.

Descriptions that follow have been allocated (from field, palaeontological and archaeological evidence set out in each part of the account) to headings based on the Geological Society's A Correlation of Quaternary Deposits in the British Isles (Mitchell and others, 1973) which has greatly facilitated classification even where its conclusions can only be provisional. The Quaternary Era Sub-Committee accept climatic fluctuation as the guiding principle for defining the stages, with the proviso that the 'basis for the number and succession of stages must, in the Quaternary no less than in earlier systems, be stratigraphical–the simple law of superposition'. Where biozones can be defined, it is nevertheless important to remember that 'they are essentially assemblage zones'. Precise chronological definition of boundaries cannot always be applied, for example, to the last major cold period, the Devensian, which is 'broadly tripartite in its climate characteristics, with a complex interstadial in the middle' (Mitchell and others, 1973, pp. 2–3).

In view of the possible analogies and probable correlations with North Kent, a summary of the Sub-Committee's findings (Mitchell and others, 1973, pp. 6–7) on correlation with stages on the Continent of Europe is given for reference:

In the Faversham area there is no problem in allocating Blown Sand and Shingle, Hillwash Head and all the observed Alluvium to the Flandrian. The Head Brickearth of the 3rd Stage clearly must bridge all the Devensian and pass into the Flandrian; lithologically, stratigraphically and climatically the deposits of this Stage appear to show much variation, and in their upper parts the brickearths grade into quite recent superficial loams. Though some may be referable to the Ipswichian, the later main body of the younger Head Gravels is essentially Devensian. Their mode of occurrence shows some of the features of the Intermediate Head Gravels in that they are intimately connected with river deposits which in part they may antedate; it is suggested that the glacial conditions their periglacial origins reflect were remote from the Thames–Medway area.

All three terraces of the Stour fall within the Ipswichian, but the First Terrace and Buried Channel deposits also probably saw the onset of Devensian glaciation control. The faunal and archaeological indicators for the Second and Third Terraces are as significant as the relative strati-graphical positions of the deposits (Holmes, 1971, pp. 166167; Mitchell and others, 1973, pp. 46, 51, table 7); further corroboration of Ipswichian age is suggested by the reference of deposits at Ilford (like those at Crayford on the south side of the Thames) to this stage, from the evidence of a temperate fauna and flora of Zones I–II (West and others, 1964).

If the relatively restricted Head Brickearth of the 2nd Stage is climatically grouped with the Ipswichian then it is possible that the Intermediate Head Gravels may represent the cold Wolstonian and the earlier Head Brickearth of the 1st Stage the Hoxnian. The Quaternary Era Sub-Committee express doubts on 'correlating deposits of the cold period between Hoxnian and Ipswichian' in south-east England 'with the type deposits of the Wolstonian stage' (Mitchell and others, 1973, p. 48); this was the view of the regional sub-committee. Qualified consideration is given (Mitchell and others, 1973, pp. 4, 9, 12) to the conclusion of Bristow and Cox (1973) that in East Anglia widespread Chalky Boulder Clay was formed in only one glacial episode, that preceding the Hoxnian. A cold oscillation such as Bristow and Cox allow between Ipswichian and Hoxnian deposits is what may have determined, however, the character of the intermediate Head Gravels, a type (see p.68) that is not entirely non-riverine in origin and includes impersistent and irregular beds of solifluction gravel that were evidently not dominated by the presence of any persistent ice-sheet close to the Thames and Medway area.

The Older Head Gravels can with some confidence be placed in the Anglian. Their mode of occurrence and position on a high dissected plateau betoken their antiquity. The presence of chalky boulder clay at Hornchurch, in Essex, underlying Boyn Hill Terrace gravels of the Thames (see Mitchell and others, 1973, pp. 46, 50, table 7) indicates nearby early glaciation that is probably Anglian. It follows that the Clay-with-Flints and Head deposits associated with it (Mitchell and others, 1973, pp. 46, 51, table 7), may rank as Cromerian and earlier (disturbed and derived or reworked materials within it range back through Waltonian, Pliocene and Eocene to the Cretaceous); its occurrence nearest to the Faversham (273) Sheet is within 1 km southward of Ospringe. As Kellaway (1974, p. 134) has recently pointed out, the first glaciation to 'have affected the British Isles in Plio-Pleistocene times' is indicated in its 'closing stages by erratics in the base of the Red Crag of East Anglia', and so is linked with the disturbed Pliocene and Waltonian contained in the Clay-with-Flints. Kellaway (1974, pp. 134–135) has further emphasised that during the period since the close of the Anglian glaciation 'Degradation and erosion of all the older glacial features and deposits took place during the period that the Saale and Weichsel glaciations were in progress in northern Europe'; these remarks apply with special pertinence to the periglacial features and deposits of north-east Kent. SCAH

Older Head Gravels

Anglian

Isolated spreads and patches of Head Gravels referred to this 1st Stage are found around Blean and in the Isle of Sheppey. In the latter area the deposits consist mainly of rough flints with pebbles of Tertiary origin but on the mainland they are generally a coarse gravelly loam with a large proportion of admixed clay, together locally with coarse-grained brown sand. The flints are either large and angular to subangular or broken up into small worn chips. They are mostly brown-stained and frequently associated with a ferruginous matrix; but near the ground surface or scattered upon it, or when admixed with practically bare London Clay the flints frequently develop a white patina. Derived materials include lumps of ironstone and chert from the Lower Greensand as well as Tertiary pebbles. The deposits showed hardly any signs of stratified bedding in the small exposures available and the materials are unsorted.

Old overgrown shallow pits on the mainland are all that remain of former local workings for road-metal and sand. On the Sheppey coast the gravel is seen to be up to 3 m thick but most of the patches elsewhere probably do not run deeper than about 1.5 m.

In addition to gravels shown on the map there are irregularly scattered ill-defined pockets of gravel and stony loam which represent the dissected 'roots' of formerly more extensive spreads of gravel disturbed by frost heaving or in some cases by bed-rock dissolution at the base. Results of solifluction and freeze and thaw phenomena are common in the London Clay areas, where also there occurs in some high plateau regions of the Blean, for instance in Thornden Wood, a peculiar mantle of fine-grained grey sand, containing a few flints, which appears to have been produced by the denudation and sorting of sand (perhaps by wind action) from neighbouring gravel patches.

The essentially clayey nature of this group of gravels has been noticed by Coleman (1952, p. 77). Their mode of origin could not have been fluviatile in the ordinary sense, but rather they probably consist of the dissected relics of sheets of drift accumulated by solifluction on an uneven slope of Tertiary beds. Although in the area there is no evidence of actual glaciation south of the Thames, it is thought that ancient high ground in the Weald and other bordering regions must have been deeply frozen at an early time and that periodic melting either encouraged sludging by solifluction or on occasions released large quantities of water in the manner of periglacial outflows which caught up the products of erosion by solifluction and re-arranged them in a crudely-bedded fashion in primitive channels of further erosion. Within the Faversham district there were probably local centres of solifluction, such as on the strong London Clay high ground, relatively resistant to denudation, for instance at Holly Hill (110 m OD). If much of the drift therefore accumulated in fan-shaped spreads it follows that only within rather broad limits can the dissected remains of these gravels be classified according to height.

Wooldridge (in Dewey and others, 1925, p. 277), referring both to the Blean gravels and more especially to other high-level gravels southward of the present area, has expressed similar views as to their origin under cold conditions and has regarded them as broadly contemporary with the fluvioglacial gravels north of the Thames, to which in fact many Head Gravels, especially those of the 2nd Stage, bear a strong resemblance when seen in section. Subsequently Wooldridge (1928, p. 12) stressed the fact that the Blean gravels are of several ages, though later (in Smith, 1933) he was inclined to refer all except the highest of them (above 100 m OD) to the activities of a primitive Stour, which he had previously suggested (Wooldridge, 1928, p. 6) might have flowed 'northwards along the western side of the Blean to effect a confluence with the Medway–Swale'. The absence of gravels or other river drift along that tract, however, makes it difficult to accept the view that a primitive Stour followed this course across the Faversham (273) Sheet.

The importance of solifluction processes in the accumulation of a large proportion of Head deposits has been discussed elsewhere (Dines and others, 1940, pp. 204–205, 222–223, etc.). The Head Gravels of the Faversham district, particularly those of the older group, would appear to be in origin largely analogous to the widespread sheets of rock-waste occurring in sub-Arctic and periglacial regions. Subsequent erosion and dissection has obscured their original character, especially in the case of the older deposits.

On the high ground near Blean patches of Older Head Gravel fringe a spread of Head Brickearth (see p.67) to which they are evidently related although at no point do they come into contact with it. It is probable that the gravels antedate the brickearth, which may have been formed partly by denudation from them after the manner of the thin sandy deposits already noted above, with an additional admixture of eroded London Clay material.

Details

In the Isle of Sheppey, gravels around Eastchurch range on the higher ground from about 70 m OD at Kingsborough down to about 55 m on the cliffs and near Mud Row. Pebbles up to 11 cm in length were noted 0.4 km NNW of Punnetts [TQ 9762 7319], where the pebbly gravel reaches 3 m in thickness in the cliff. The largest spread extends north-north-east from Kingsborough. Blue and grey-coated pebbles of average size, 4 cm, predominate but there are also battered brown and red flints. In the cliffs broken red-stained flint pebbles were also seen. At a point [TQ 9851 7309] 0.8 km N of Garretts up to 3 m of crudely bedded and contorted sand and gravel, locally ferruginous, was observed overlying the Bagshot Beds. The two small patches between Eastchurch and Mud Row consist of sandy gravel with pebbles and the capping on the hill 0.4 km southward of Eastchurch is similar.

On the mainland the highest patch of gravel is on the south-west, at Holly Hill [TR 076 606], around 110 m OD, but it is uneven and pocket-like and tends to be concentrated on the western slope of the hill; it is a sandy gravel generally not more than 1 m thick. A little thin wash of similar material may occur elsewhere on adjacent high ground. At 2.4 km to the east another patch occurs at about 90 m OD in North Bishopden Wood, where it mantles a gentle northerly slope. Old pits [TR 0990 6025], [TR 0996 6025] exposed the drift to a depth of 1.8 m showing a coarse orange sandy loam, with abundant flints in its upper part, passing downwards into a cleaner grey and orange coarse-grained sand. In one place the whole deposit was seen to be gravelly, with many large brown subangular flints, small worn chips of flint, black Tertiary pebbles and lumps of ironstone, all without noticeable sorting or bedding. At Clapham Hill, on the Whitstable road, an outlying mass of the Blean gravels was noted by Wooldridge (1928, p. 12). It forms a well-defined capping of the hill at about 65 m OD on the north, falling to 60 m on the south side. Old pits [TR 1035 6404] were formerly dug to 1.2 m or more in coarse orange sandy loam with large ochreous flints, small broken chips of flint and Tertiary pebbles. Some 180 m from the western end is a very small patch of flinty loam (not shown on the map) on the crest of a spur of London Clay.

The gravel at Clowes Farm occupies the north-western slope of a hill from about 70 to 55 m OD. W. Whitaker, in MS notes, described a section north-east of the farm which in 1864 showed 'loamy soil passing down into brown sand, about six feet (1.8 m) deep, with, near the bottom, a bed of coarse grit (or very fine gravel) composed of small roundish pieces of flint; and at the bottom larger flints'. This pit [TR 1212 6287], 140 m NE of the farm, exposed coarse-grained red-brown sand with a clayey matrix in the upper part when seen in 1939. Another patch of gravel southward of the farm has been dug to about 1.5 m in numerous shallow pits [TR 118 623], where the deposit was seen to be dominantly stony, with Tertiary pebbles and subangular brown flints in a sandy matrix. Small patches of sandy flinty loam occur on sloping high ground a little above and below 60 m OD at points respectively 410 m ENE and 960 m NE of Clowes Farm. At Shrub Hill clayey sand and flints caps the ridge at 57 m OD, while another ridge, above 60 m OD, extends from 0.4 km southwards and carries sandy gravel, seen covering sandy clay in old pits [TR 139 640] up to 1.5 m deep.

Four isolated patches of loamy gravel have been distinguished in Thornden Wood, where they rest on a plateau at a little over 60 m OD. The two on the north are composed of flinty sand and loam, up to 1.2 m or more in thickness, whereas the patches on the south are of gravel, with sand, formerly dug to 1.8 m in old pits [TR 142 630]. About 0.8 km NW of Cane Wood there are in the London Clay surface small pockets of a sandy drift which includes subangular flints, Tertiary pebbles and lumps of ironstone and chert derived from the Lower Greensand. But the flat area of Thornden Wood roughly bounded by the four gravel patches mentioned above is itself mantled by a very thin spread of fine-grained grey sand, locally with a few flints; it forms a conspicuously sandy soil in an area of otherwise very stiff clay, but it is rarely more than 0.5 m thick.

At Clowes Wood, Honey Hill, Blean and Tyler Hill a series of patches of gravel above 60 m OD are distributed in a pattern related to the spread of high-level Head Brickearth north-east of Blean. The gravels are not in contact with the brickearth, nor does gravel generally underlie the latter, but from their position and dissected nature it is probable that the gravels are older than the brickearth. Two patches on the south of Clowes Wood, one of them very small, are both very sandy. Three others eastward of Honey Hill are similar, the one nearest that place being thickest and throwing out a strong spring; a small pit [TR 1172 6156] exposed 1.2 m of coarse-grained clean orange sand with no flints, and without penetrating the London Clay. West of the road from Honey Hill to Blean two members of a group of three patches of flinty coarse-grained sand and loam appear to be related to a small tongue of brickearth. The small patch situated immediately east of the road through Blean village is on a southerly slope and is very stony and clayey. Between Blean and Tyler Hill a relatively extensive spread of gravel is not quite dissected into two portions. It consists of gravelly loam and orange sand, with workable gravel on the south-east spur, where old pits [TR 1365 6059] dug to 1.5 m showed moderately coarse to fine subangular flint gravel with Tertiary pebbles in a coarse-grained sandy matrix. Wooldridge (in Dewey and others, 1925, p. 277) has referred to the high-level Blean gravels on the Tyler Hill plateau northward of Canterbury. At Tyler Hill coarse-grained sand, gravel and loam caps the hill at about 70 m OD and about 0.8 km NE, in Honey Wood, another small capping is present. A tiny hill about 70 m OD just north-east of Well Court carries a capping of gravel too small to be indicated on the map.

Three isolated patches of flinty coarse-grained sand are aligned along the crest of the ridge north-eastwards of The Park; at the south-west end the ground-level is about 65 m OD but the patch on the north-east, which includes ironstone and Tertiary pebbles among the constituents, is somewhat below 60 m OD in level.

Head Brickearth, 1st Stage

Hoxnian?

What appears to be the oldest brickearth in the Faversham district is found only on the high plateau northward of Blean, where it slopes gently from about 80 m OD on the west down to 70 m or less on the north and east. It consists of a dull brown, or rarely orange-mottled, compact loam, mostly heavy and clayey but worked or weathered to a finer light loam soil in places. Flints, or Tertiary pebbles, are only occasionally included but were noted in a few places at the margins of the spread. At a depth of about 1.2 to 1.8 m the deposit passes down almost insensibly into stiff clay which is usually the top of the London Clay, practically undisturbed. The spread is quite clearly limited on all sides except for the spur south of Well Court, where no separation could be traced between the high-level brickearth and a brickearth deposit which extends down into the narrow valley at Brittencourt Farm.

The relationship of the high-level brickearth to the festoon of gravel patches surrounding it suggests that the deposit is later in age than the gravels, for although the latter cannot be shown to underlie the brickearth, that deposit tends to be a little stony at the edges and in contrast to the gravels it is undissected except by superficial late erosion on the north-east. In origin this particular brickearth may be largely wind-borne (cf. Pitcher, Shearman and Pugh, 1954, p. 313), for it appears to be structureless, unbedded, uniform in thickness and practically stoneless or without the interbedded gravels so frequently associated with brickearths of the later stages. There may be some points of comparison with the accumulation of the thin soils of fine-grained sand in the region of Thornden Wood (above) and West Blean Wood (p. 70) but some special conditions must have obtained at Blean to encourage the formation not only of a much thicker deposit but also a more clayey one. Possibly a preceding period of erosion and dissection of Older Head Gravels and London Clay, under cold conditions, produced a shallow depression in which boggy soils may have developed on the clay land; sand derived from the denuded gravels, perhaps in all but the earliest stage transported by wind action (not necessarily under arid conditions), would by this means conceivably be anchored to and admixed with muddy clay to form a heavy type of brickearth. Drainage of the area, at a much later date, evidently influenced the initiation and development of streams on the east and south-east connected with the Sarre Pen stream. SCAH

Details

Apart from degraded sections along the former Whitstable Harbour Branch railway the brickearth was seen only in ditches and occasional temporary exposures, but it forms a distinctive type of arable land with a fertile soil, set in a general region of stiff clay land, heavily afforested. The cutting [TR 130 621] 0.8 km NE of Amery Court showed up to 1.8 m (or more) of brown brickearth, rather clayey, especially at the base. To the south-east this thins out and its basal very sticky clay gives place to solid London Clay, which is at the surface less than 0.8 km eastward of Amery Court. The solid clay carries, however, some irregular sandy and flinty wash and small pockets of brickearth. A continuous deposit of brickearth was observed, to a depth of 1.2 m in the cutting [TR 1355 6130] 0.8 km NW of Tyler Hill.

The brickearth was seen to be a little stony at the border of the spread at the following points: 8.8 km WNW of Tyler Hill [TR 134 611] (ochreous flints and pebbles), about 0.4 km [TR 119 612] and also 0.8 km [TR 121 608] SE of Honey Hill, 0.8 km NNE of Cutballs Farm [TR 1266 6231] (coarse, loamy) and less than 1.2 km NE of Amery Court [TR 1324 6233]. There are flints in the brickearth within 0.8 km of the Blean road but beyond Cutballs Farm these are absent.

A narrow tongue of brickearth on the south-west side of the Blean road is almost in contact with two small patches of Older Head Gravel. SCAH

Intermediate Head Gravels

Wolstonian?

The gravels of this group differ from the Older Head Gravels in the following ways: they are found at lower levels and are more widespread, thicker and more variable in type and they include compact rough gravels, showing stratification on a broad scale or a little cross-bedding locally, which have points of resemblance to river gravels though they are not typical cross-bedded and sorted terraced deposits; they have also yielded implements and vertebrate fossils. In general mode of origin, however, they appear to be similar to the earlier gravels and they are succeeded by a brickearth which in this case, however, has been preserved in contact with them over considerable areas. Palaeolithic flint implements for the most part described as 'Chellean' have been found either in these gravels or presumably derived from them. Vertebrate remains include records of the mammoth Mammuthus primigenius from drift in the cliff at Stud Hill, west of Hampton (p. 69), an important accessory in applying a relative date to the deposits, for this species only began to establish itself during the Penultimate Glaciation (end of Middle Pleistocene) in the usage of Zeuner (1959, pp. 319, 335–336).

A thickness of some 3 m is general for these gravels, but they may reach 4.6 m and strongly dissected remnants of larger spreads may be no more than 1.5 m thick. They are essentially coarse subangular flint gravels containing sand or sandy brickearth seams 0.3 to 0.6 m thick, often with chips of white flint, and occasional clayey partings. The flints are mahogany, brown, yellowish or white; some of them are considerably abraded but others are large irregular nodules derived from the Chalk without much attrition. Other constituents are brownish and black Tertiary pebbles, lumps of ironstone and, more rarely, compacted sandstone blocks ('sarsen stones') derived from the Thanet Beds. The common ochreous sandy matrix is frequently strongly impregnated with iron and is locally hardened and cemented by it.

For the most part the gravels are relatively unsorted and crudely bedded; cross-bedding is rare and confined to beds and lenticles of fine gravel. There are some beds of better-rounded flints, however, and in the regions of Stonerocks Farm, Westbere and Stodmarsh, bordering the Great Stour valley the gravels approach the Stour terraced gravels both in type and mode of occurrence; here, however, they can only be described as crudely bedded without clear axial arrangement of the materials. These are the implement-bearing gravels to which Dewey and Smith (1925, p. 134) have referred, pointing out that they and similar deposits on the south side of the valley above Fordwich, on the Canterbury (289) Sheet southward of Sturry, are 'well above the terraces of the Stour and are (or were) continuous with the great spread now covered by the Forest of Blean'. In a section [TR 1954 6117] about 370 m ENE of Westbere Church ill-sorted Head Gravel at the top was seen to pass down to more clearly bedded gravel with coarse-grained sand. A better section [TR 1910 6174] some 550 m ENE of Stonerocks Farm (p. 70) exposed, at one stage in gravel excavations, a succession of rough unsorted Head Gravel (0.9 m) followed by cross-bedded sands with clay partings (0.6 m) overlain by compact rough Head Gravel passing laterally into stony loam and brickearth (1.6 m). Points of special interest are the examples of typical interbedding of Head Gravels of this stage with the succeeding Head Brickearth, and of the mixed nature of the gravels at Stonerocks Farm, Westbere and Stodmarsh. At these localities, too, the deposits show a tendency to be disposed a little on the sides of the Tertiary plateau and are perhaps to some extent benched into them.

On the western side of the valley near Faversham leading from Syndale Bottom to Oare are a number of patches of Head Gravel which are aligned in a related fashion superficially suggestive of river terraces. Those on the higher ground south-westward of Oare (p. 69) are referred to the Intermediate Head Gravels; their terrace-like disposition and also that of the Younger Head Gravels, at a lower level, separated from them by steep drift-free slopes (cf. Dines and others, 1940, p.207) is a result of subsequent erosion and dissection, whether by periglacial solifluction processes or by temporary fluvial action. This took place during the later stages of the development of the dry-valley system which here enters the Faversham area from Doddington and Newnham on the Maidstone (288) Sheet to the south-west, where also there are extensive Head deposits but river gravels are absent. Sections on the hill in Bysing Wood 1.2 km SW of Oare (p. 69) showed a dovetailing of rough subangular gravel with sands of the underlying Woolwich Beds which together gave a false appearance of cross-bedded sandy gravels. SCAH

Details

Gravels referred to in this group occur in the Isle of Sheppey only along the northern coast, from Warden Point westwards for about 2.5 km. Compared with the Older Head Gravels they occur at lower levels, averaging about 45 m OD and, as clearly recognised by Prestwich (1890, p. 143), they are of different lithological character. The drift at the headland (Draper's Point) [TR 0009 7303], some 0.8 km NNW of Mud Row, consists of about 3.5 m of crudely cross-bedded sand and gravel with brickearth. This deposit was more fully described by Prestwich before extensive coast-erosion, who saw 'from 15 to 20 feet (4.6–6.1 m) of yellow sands with seams of clay and patches of gravel, the bottom bed of gravel being from 1 to 2 feet (0.3–0.6 m) thick, and composed essentially of flint-pebbles of various sizes, of large subangular flints much worn and stained brown, numerous small flint-fragments, and some very small pebbles of quartz'. He also found brown chert in the basal gravel. The beds he regarded as not improbably 'of Westleton age' and stated that 'they are overlain by a flint-gravel in small pockets'. Prestwich concluded (1890, p. 179) that a 'Southern Drift' derived from the slopes of the anticlinal of the Weald may have continued to form during the later period of the Westleton Shingle of Norfolk, which he sought to trace south of the Thames and elsewhere. A reconsideration of the Westleton Beds by Hey (1967, pp. 427–445) has led, however, to a separation of such outlying occurrences of pebbly gravels from the beds in the type area. The Sheppey gravels are in any case probably younger in origin, and both the southerly and locally derived materials (such as the pebbles) are the natural constituents of a 2nd Stage of Head Gravels.

The tiny patch of gravel shown just to the east of the main spread consists of angular and subangular red and blue flints with blue-coated pebbles up to 18 cm in length. A little westward [TR 0190 7251] of Warden Point patches of gravel 2 m thick consist of pebbles and flints with coarse-grained sand and seams of clayey sand, resting irregularly on the London Clay. SCAH, SB

An Intermediate Head Gravel stage is clearly recognisable in the country south-west of Faversham, and was in fact noticed many years ago by T. Mc K. Hughes, who in MS notes has referred to an 'older gravel' occurring at considerable and varying heights and possibly of several different ages. One of the areas in which dissected spreads have the appearance of terraces is that described by Hughes 'near Bysing Wood, W. of Faversham' where patches of gravel 'frequently form a perfectly flat-topped hill', as do others

'on the S. side of the Watling Street'. Not only, however, do the gravels fail to exhibit the characteristics of river deposits but also the drift at lower levels on the north and east is distributed wholly in the manner of head deposits, consisting of intimately associated gravels and brickearth and mantling the hill-slopes.

There are four patches of gravel in Bysing Wood south-west of Oare, all of which are composed of mixed subangular flints and Tertiary pebbles, with a coarse-grained sandy matrix. Their height varies from about 40 m OD on the south-west to 30 m on the north-east and 35 m on the south-east. The best sections were on the Faversham road a little north-west [TQ 9952 6224] and south-east [TQ 9960 6212] of the crossroads at the top of the hill, the former showing up to 1.8 m of gravel which thins irregularly down the hill and dovetails with sands of the Woolwich Beds below. The drift in the south-easterly section was described by Hughes (in Whitaker, 1872, p. 161) as a 'mixed angular and pebble gravel; probably derived in greater measure from older pebbly gravel, but the pebbles may have been derived directly from denudation of Tertiary pebble-beds further south'. The older gravel referred to would be Older Head Gravel of the present classification. Hughes also noted the 'kind of dovetailing of resorted Woolwich sand with the gravel' at its base. As visible in 1938 there were 1.8 m of unsorted and unbedded gravel, mostly compact, considerably iron-stained and containing large irregular flints derived from the Chalk without extensive abrasion. There were also small pebbles, a few chips of flint and a little loam or brickearth on the south-west.

Farther south-south-west six isolated patches of gravel, generally some 1.5 m thick, two bordering the railway and one cut by Watling Street, are aligned at heights over 45 m above OD, but a larger spread of rough gravel, with many large irregular flints, 0.4 km to the east of Beacon Hill is on a slope and descends to about 25 m OD before it is limited by a steep valley side on the south-east. Of the six smaller patches the one exposed in the Watling Street road-cutting [TQ 9862 6141] is of interest because it contains lumps of 'sarsen stone' and ironstone in addition to the usual subangular flints and Tertiary pebbles.

The spread of gravel at Judd's Hill forms a plateau at about 45 m OD, sloping very gently north-east. On the opposite side of a small valley there is gravel at about the same level 0.5 km SW of Ospringe; but its boundaries are obscure, for it is overlapped on the north-east and east by brickearth referred to a later stage.

Faversham itself is situated on drift of the 3rd Stage of Head Deposits, so that the next locality where Intermediate Head Gravels occur is 1.2 km beyond Goodnestone, where at about 30 m a very narrow ridge of pebbly subangular gravel with ironstone caps the outlier of Oldhaven Beds shown at Waystreet Farm. These gravels are the only occurrence in this region except for a tiny patch which caps a knoll 500 m NW of Hernhill Church.

Along the coast between Whitstable and Reculver the dominant type of drift exposed is Head Brickearth but there are also a number of patches of gravel of the 2nd or Intermediate Stage. All these drifts are of special interest in view of the mammalian remains and Palaeolithic implements which have been found in that region. At Stud Hill, between Swalecliffe and Hampton, a patch of gravel at about 18 m OD was formerly seen, but although shown on the Old Series Geological Sheet 3 it has now been completely eroded away (see p. 102). In 1939 some shallow pockets of drift [TR 1498 6772] remained, consisting of crudely interbedded subangular gravel, coarse sandy stony brickearth and stony chocolate clay. According to Dr A. Bowes, who was able to supply a list of specimens in the Herne Bay Museum, both Mammuthus primigenius and Palaeoloxodon antiquus have been found in the cliff. The latter appears to have come from fissures in the London Clay but the former has been recorded from the gravels, in which Evans (1897, p. 617) found a portion of a molar. Many other tusks and bones of this species have been recovered from the shore. They have probably been washed out of the same deposit; it should also be noted that Whitaker (in MS) mentioned the presence of bones in the soil above this gravel. Human artifacts found near here may derive from the gravel; the one figured by Evans (1897, p. 618) is seemingly a primitive type which may have been derived from an old pre-existing land surface. Specimens of the land shells Pupilla muscorum and Succinea oblonga were obtained by the late A. S. Kennard from 'Studhill Cliff' presumably in the less gravelly part of the deposit formerly to be seen, if not from a deposit of more recent origin.

Another patch of loamy gravel caps the hill east of Hampton, where it is at 23 m OD on the west falling to 18 m OD eastward. Whitaker found that it rests on the London Clay with an irregular contact.

The next gravels in the cliff are eastward of Herne Bay. A patch on the hill 0.8 km NW of Beltinge reaches about 40 m above OD. Whitaker saw a 1.8 m pit 'in coarse brown and whitish sand with pieces of flint' and noted that there were also indications of gravel elsewhere. A pocket of head gravel to 2.1 m was proved at the Herne Bay Water Works shaft [TR 1873 6788] a little to the south. Farther to the east, the numerous patches of drift are essentially brickearths but a large spread of gravel at Hillborough extends to the cliffs [TR 210 688] at above 30 m OD at Bishopstone, and a tiny outlying patch remained in the cliff edge in 1938 at a lower level 0.5 km to the east. The Bishopstone gravels are unevenly bedded, sandy and ferruginous and include interbedded seams of brickearth, with lenticles of gravel; Whitaker saw 2.4 m of the deposit resting irregularly on the London Clay and 'made up of flints (large and slightly worn, broken and subangular), flint-pebbles and a few pieces of sandstone'. Hughes (in MS) regarded these pebbly gravels east of Herne Bay as similar to the high-level gravels west of Faversham (above) and drew attention to the fact that many flint implements have been found along the beach below. It is now known, however, that drifts of several ages are represented in these cliffs, or were present there in earlier stages of coastal erosion. It is also almost certain that many of the artifacts came from younger deposits including the Head Brickearth of the 3rd Stage (see p. 91), into which some were probably incorporated from an older land surface. Nevertheless, some examples are known to have come from the Bishopstone gravels or equivalent deposits, as noted by Evans (1897, p. 617) and by Worsfold (1926, p. 334), who records a 'Chellean' type. Evans (1897, p.612) figured an implement from the beach between Herne Bay and Reculver which has also been compared to 'Chellean' forms (Jessup, 1930, p. 14) and may well have been washed out of these older gravels. Smith (1918, p. 112) drew attention to the significance of early types of implements among others obtained from the Reculver cliffs. He suggested that the Blean gravels, of which the high-level drift at Reculver is a terminal part, may have 'originally formed part of a vast sheet spread over watershed and valley alike', at a time when river development was relatively little advanced.

Intermediate Head Gravels in the central area of the Blean occur as scattered dissected relics of what was probably an extensive sheet of drift which trailed down gentle slopes to join the more continuous spreads of gravel, at a rather lower level, near Hoath and Highstead. Three small patches of gravel about 1.5 km NE of Tyler Hill appear to belong to this group, rather than to the 1st Stage, for they are at a distinctly lower level (about 50 m OD) and are separated from the latter deposits by a bluff of London Clay. There is only a very narrow ridge of gravel at Langton Lodge but 320 m to the south-west a temporary trench [TR 1509 6161] showed crudely bedded clayey gravel, with a maximum depth of 1.8 m, consisting of white and brown battered subangular flints, large and small Tertiary pebbles, lumps of ironstone and locally sand; the surface of the London Clay beneath the drift is very irregular. The third patch, at Mayton Farm, is too small for indication on the map but Whitaker (in MS) noted a section here in bedded buff and brown sand with flints and pebbles. The gravel at about 50 m OD near Blaxland Farm also includes pebbles and ironstone; 1.2 m of drift was seen [TR 1616 6314] 90 m south-west of the farm. A small patch some 450 m farther north is at 56 m OD, but appears to belong to the present series rather than to an earlier gravel, for it is part of a group of four patches which lie on the high ground of West Blean Wood. Eastward of these a considerable area of this wood has, on the high ground, irregular pockets or a thin surface soil of re-worked sand and flints somewhat comparable with similar deposits at a higher level in Thornden Wood (p.67), but the drift is less uniformly or strongly developed and does not mask the London Clay so extensively. It is noteworthy that the incidence of even an impersistent sandy soil in areas of West Blean Wood has proved an asset for chestnut planting. Further denuded relics of gravels again bound the area on the east side of the Herne Bay road where small patches of loamy or sandy gravel were noted at about 50 m OD 0.4 km NW of Hicks Forstal and at about 43 m OD near Woodlands. An old pit [TR 1797 6309] in the patch nearest to this farm showed almost 1 m of unsorted subangular gravel with Tertiary pebbles, in a loamy matrix, resting on the London Clay. Gravel in East Blean Wood is confined to an area on the south, 0.8 km E of Hicks Forstal, where thin gravelly loams at about 44 m OD appear to mark a focal point from which drift may have extended to form the gravels preserved as relatively extensive spreads at a lower level around Hoath (see p. 71).

High-level gravels on the plateau bordering the Great Stour on the north-west side are grouped with the Intermediate Head Gravels. They are similar to the other Blean gravels in position and general character but it is especially in this tract that some of the gravels show features like river gravels, including a tendency to be benched into the gently sloping London Clay of the Blean borderland.

Gravel was formerly dug about 0.8 km SW of Shelford Farm, at about 52 m OD. Whitaker (in MS) described here 'brown gravel, of subangular flints and flint-pebbles, with discontinuous beds of brown and grey sand, and one part a bed of light-bluish-grey clay'. The amount of drift remaining here is too small to indicate, but the gravel extends southward of the border of the Faversham (273) Sheet, where it is grouped with the 3rd Terrace River Gravels so designated on the Canterbury (289) Sheet. Numerous isolated patches of gravel diversify the London Clay plateau around Shelford Farm and Broadoak, at about 49 m OD rising slightly on the north and falling to 46 m on the south-west. They are bounded on the north-west by a ridge of London Clay which carries only a little gravelly soil derived from pockets at over 55 m OD which probably represent the 'roots' of Older Head Gravels. The Broadoak gravels appear to be somewhat hollowed into a rather irregular surface of London Clay. They all include loam, coarse-grained sand and large, comparatively unworn, flints but only small exposures were seen. Springs tend to be thrown out from these drift patches and also locally from stony pockets in the intervening London Clay tracts. The large sand-pits [TR 162 602] 0.5 km S of Shelford Farm have exposed pockets of stony drift in the London Clay capping the hill. Angular gravels with large flints, flint chips, ironstone and Tertiary pebbles, in a coarse sandy or clayey matrix, have been seen from time to time but are so disturbed by intense frost action (see Edmunds, 1953, p.22), which has also produced small-scale faulting in the underlying Tertiary beds (p. 41), that their appearance at the surface is too limited and irregular for representation on the map. It was hereabouts that Smart (in Smart and others, 1966, pp. 244, 269) also observed that 'the surface of the London Clay is covered by a mélange of disturbed gravel, sand and clay formed by cryoturbation during successive cold periods' and described the disturbed relics of his 3rd Terrace as seen, contorted together with London Clay, in the Shelford Sand-pit.

A continuous spread of gravel at about 49 m extends from the Herne Bay road to Hawcroft Farm. A temporary trench [TR 1774 6163]-[TR 1781 6143] was cut through this about 230 m W of the farm and exposed, from north-north-west to south-south-east, firstly ochreous unbedded gravel and loam with Tertiary pebbles and some very large Chalk flints, then crudely bedded gravel to 1.2 m on clay and lastly 0.6 m of gravelly loam on stiff clay. Three small patches of similar drift occur east of Hawcroft Farm.

The gravels east of Stonerocks Farm, on the plateau north-west of Westbere, were thicker and more extensive but have been reduced by active working over a long period. The gravel south of Hoades Court at about 43 m OD appears to be continuous with the main spread, which falls from 42 m OD to 37 m OD on the east and 34 m OD south of the Sturry road. Dewey and Smith (1925, p.134), referring to gravels at Stonerocks gravel-pit and at Fordwich, on the Canterbury (289) Sheet (see p.64), southward of the Stour, state that 'at both localities several Palaeolithic implements of the Chelles type have been found, and presented by Dr Ince to the British Museum'. A rolled ovate of this type from the gravels of the plateau is in the Geological Survey collection [M.I. 25548]. In 1946 and 1951 good sections [TR 192 617] were seen within 0.4 km northward of the Westbere Butts Inn on the main road to the Isle of Thanet. The gravel thins out above the London Clay on the north and east but on the south-west is about 3 m thick. Mainly it is only crudely bedded, with large and small flints jumbled together without axial arrangement. The only distinctly sorted beds are seams of fine sandy brickearth about 0.3 m thick, sometimes containing many tiny chips of flint, and several parallel 0.02 to 0.15 m seams of whitish clayey loam or pipe clay seen on the south-west. Some of the flints are very large and little worn, while their colour varies from white to brown or mahogany. Among the other constituents are Tertiary pebbles, occasional 'sarsen stones', large grains of quartz and lydite and a few small fragments of ironstone. The matrix is mostly a very coarse-grained impure sand or loam. In one place [TR 1918 6177] 0.6 m of unbedded gravel was seen to overlie a local development of fine-grained gravel, cross-bedded with foresets to the east. More variable beds were seen in 1951 at a point [TR 1908 6170] 320 m NNW of the inn and about 550 m ENE of Stonerocks Farm, where the section demonstrated that the brickearth of an adjoining small patch overlies them. Details were as follows:

Eastward the top bed was replaced by unsorted compact gravel but the beds below were somewhat cross-bedded sandy loams with clay partings, resting again on unsorted gravel without alignment of the constituents. The bedded middle gravels may have been river deposited, preceded and immediately followed by periods of solifluction. In 1967 the previous workings had become obscured by flooding, but southward in the direction of the inn some new diggings around [TR 1915 6150] continued to exploit an unsorted clayey ochreous gravel, about 3 m thick, on London Clay seen on the west; it was planned to extend these workings farther east. The limit of the gravel spread is close, for London Clay was observed 'fingering' into the drift and 1.2 to 1.8 m of clayey brickearth (in part disturbed artificially) were seen to overlie the gravel; in the latter were lenticles of whitish clay mixed with very fine gravel, with iron-staining at their base and perhaps traces of manganese. The lack of cryoturbation of the drift in all these sections is possibly explained by the former protective cover of 2nd Stage Head Brickearth.

In the large old sand-pit [TR 185 613] 1 km NE of Sturry station, rough unsorted gravel occurs in pockets, up to 45 m across, festooned and 'piped' into the London Clay (see p. 50). These are the frost-disturbed 'roots' of eroded head gravels originally at about the same level as the gravels described above.

A spread of Head Gravel, falling from 37 m OD to about 30 m OD, extends from above Westbere east-north-east for about 1.5 km; the gravel is about 1.5 m thick in old workings [TR 198 615] 0.4 km from its western limit, where lumps of ironstone from the Lower Greensand were noted in a gravel of large and small comparatively unworn flints. A transition to flinty brickearth is found on the north-west, beyond which another area of gravel occupies the hill north-east of Breadland Farm.

Along the road through Upstreet two patches of similar gravel are dissected parts of a formerly continuous thin sheet of drift trailing from over 27 m OD near Hersden down to 21 m OD at Upstreet. On the north-west side of the valley near Chislet Park four small patches of sandy gravel within 0.8 km south-west of Chislet Forstal are dissected relics of a sheet of drift at similar levels.

Around Hoath the topographic position of the Intermediate Head Gravels and their relationship to Head Brickearth of the 3rd Stage is shown in (Figure 7). These gravels are parts of a fan of drift bordering East Blean Wood on the south and east. At Buckwell gravel is grouped in four patches, two of them small, ranging from 39 m OD on the west to 30 m OD on the east, where the gravel, about 1.5 m thick, slopes south–east with the hill. SCAH

The working pit [TR 196 633] at Rushbourne Manor in 1976 showed up to 3.5 m of poorly sorted gravels with a fine-to-coarsegrained sand matrix. The gravel comprised mostly angular to sub-angular flints with subordinate rounded black Tertiary flints. A local poorly defined cross-stratification was picked out by lenses and beds, up to 0.5 m thick, of orange silty sand with subordinate fine gravel. Beds, up to 2 cm thick, of well sorted greenish yellow, medium- to coarse-grained sand were noted near the base. The London Clay surface showed numerous ridges and pinnacles up to 3 cm across and reaching to within 0.2 m of the surface in places. The pinnacles had nearly vertical extremities and the adjacent gravels showed strong cryoturbation features. RAE

North-west of Rushbourne four separate patches of gravel and gravelly loam around 30 m OD are aligned in a north-easterly direction. These slope south-east from the higher ground fringing East Blean Wood, where an irregular spread of gravel (p. 70) was probably continuous with them at one time. The drift may have been deposited as part of an 'outwash' fan under periglacial conditions. The more extensive spreads stretching from Hoath to Old Tree and near Maypole for the most part lie comparatively evenly at around 34 m OD; they appear to form part of the same natural series of gravels, however, the whole of which have been eroded and dissected at a later period culminating in the deposition of Head Brickearth of the 3rd Stage which overlies them and occupies the Rushbourne valley (p. 92). Gravel pits [TR 2020 6425] 90 m NW of Hoath church showed 3 m of unsorted crudely bedded gravel with ferruginous sand, loamy seams, lenticles consisting largely of fine chips of unworn flint, and Tertiary pebbles. There are indications that the adjacent spread of brickearth is later in date and overlies the gravel. Bowes (1928, p. 517) described a series of palaeoliths from this locality of which one, a heavily rolled implement of 'Chellean' type was undoubtedly incorporated in the main gravel from an older land surface, while the two others are considered to be related to later stages and deposits (see p.92). A temporary section at Hoath proved that the gravel cannot exceed about 3 m in thickness and a similar figure was indicated in old pits at Millbank. Within 0.4 km E of that place the gravels vary from fine to coarse and from 0.9 to 2.4 m in thickness, as seen in several old pits.

About 0.8 km SE of Herne a small spread of gravel with coarse-grained sand extends from Ridgeway Farm north-eastwards to a point at 43 m OD on the hill of London Clay. A deep valley separates this from similar gravels farther north-east.

These gravels, near Broomfield, Highstead and Beltinge, form an extensive tract largely overlain or overlapped by brickearth in the northern half. Various overgrown small sections in the southern part showed sandy gravel of variable grade with occasional pebbles and lumps of ironstone. South-east of Highstead there were old gravel pits (noted by Whitaker, in MS)–dug to a maximum of 3.4 m in gravel with thin seams of loamy brickearth or of coarse-grained ferruginous sand. Dewey and Smith (1925, p. 134) recorded the following section at Highstead:

A quarry [TR 218 658] at Highstead showed the following section in 1976:

The gravel which shows at the surface at Blacksole Farm, on the west of the brickearth area, was seen by Whitaker in the railway cutting. His description (in MS) indicates reddish brown fine sandy gravel overlying the London Clay somewhat irregularly and itself overlain by brickearth. Coarse-grained sand with flints emerges from under the brickearth in a narrow strip at the bridge (Bogshole Bridge) 0.8 km E of Blacksole Bridge. Whitaker noted up to 3.7 m of drift hereabouts, 'water being thrown out at the junction' of the gravel with the London Clay. He observed that eastward the gravel wedged out between the clay and the overlying brickearth. Dowker (1864, p. 339) noted pebbly gravel in the railway cutting 'near Maystreet, towards Hillborough'; this occurrence seems to be either a pocket of gravel in the London Clay or a stony pebbly development of the adjacent brickearth. On the east of the main spread of gravel and brickearth isolated small patches of gravel occur at 30 m OD about 640 m E of Hawthorn Corner and at 21 m OD at Chislet Windmill, 0.5 km SE of Brook Farm.

The sandy gravel, with pebbles, around Hillborough is in contact with brickearth on the south-west and extends northward to the coast at Bishopstone (see p. 69). The spread has a gentle inclination eastward from about 36 m OD down to 30 m OD.

Two small areas of relatively high-level gravel on the south-east side of the Great Stour valley are referred to the 2nd Stage of Head Gravel. The spur at about 26 m OD 0.8 km WSW of Stodmarsh carries gravel, subsequently dug away to a large extent, showing a very irregular surface of Thanet or Woolwich Beds beneath. The drift is also very variable, either rough and unbedded compact gravel or locally sorted and bedded in the manner of a river-laid deposit. In old pits 600 m WSW of Stodmarsh church Whitaker (MS notes) saw a section in 'about eight feet (2.4 m) of brown gravel, false-bedded in the same direction as the fall of the valley, that is north-eastwards', but sections [TR 2145 6026] visible in 1946 showed only some 1.2 m of the gravel, resting on Woolwich Beds. The flints are white and battered, or in small white chips, or stained chocolate, and are accompanied by Tertiary pebbles, especially at the base, and occasional lumps of 'sarsens'. The matrix is a coarse sandy loam with a few impersistent and irregular clayey partings. The other area of Intermediate Head Gravels is around Grove Hill at 21 m OD and the locality known as Sandpits, 0.4 km SSW, at about 18 m OD. At both places crudely bedded rough gravel contains many large and small pebbles derived from the nearby Oldhaven Beds, and at the base the gravel includes finer sandy lenticles, with chips of flint. The drift is an uneven spread, seen in old pits [TR 2270 6045] to be about 1.2 m thick, overlapped by a later brickearth on the south-west and becoming very clayey where a tongue extends on to London Clay to the north-east of Grove Hill. SCAH

Head Brickearth, 2nd Stage

Ipswichian

This deposit is more or less intimately associated with the Intermediate Head Gravels and from its field relationship to them it is clear that the brickearth was laid down at no great interval of time after them. It is present in only two general areas, on the plateau bordering the left bank of the Great Stour and at the coast or near it to the east and southeast of Herne Bay.

The dominant type of the drift is a dense yellowish compact loam with a variable content of unworn flints and locally some Tertiary pebbles. Thin or irregular gravelly and sandy beds also occur and the brickearth is overall much less uniform in character than that of the 1st Stage. Its thickness is probably nowhere more than about 4 m.

The interbeds of gravel where this underlies it and the inclusion of many stones and stony lenticles are features which indicate that the deposit is not primarily of aeolian origin. Lack of lamination, or bedding and sorting of the constituents, and also the uneven distribution of the brickearth on the underlying surface, equally preclude the probability of deposition by waters of river or lake. Rather, it is thought to be a true head deposit, accumulated in much the same manner as the Head Brickearth of the 3rd Stage, in the account of which some theories of origin are more fully discussed.

There appears to be no record of shells or vertebrate bones having been found in brickearth of this stage, but at the coast some of the flint implements collected on the foreshore probably came from it (see below) for one, 'an unrolled hand-axe of Chelles Type', was found in situ in the gravelly base to the deposit (see below) at a point about 1100 m west by south of the ruined church at Reculver (Burchell, 1924, p. 207). Whatever age can be assigned to this implement (others which may have come from the brickearth have been considered Acheulian types) it is probable that the thin gravel at the bottom of the brickearth is closely related to the older land surface upon which the gravels of the 2nd Stage were deposited.

The dissected nature of these brickearth spreads distinguishes them from the similar drift of the 3rd Stage, which is closely related to present topography or to slopes which have been modified comparatively slightly since late Pleistocene times. Brickearths of the 2nd Stage, on the other hand, cap plateaux or gentle hills or lie somewhat channelled into the bed beneath, which is most commonly the London Clay. SCAH

Details

In the small area of brickearth, surrounded by gravel, about 0.8 km NNW of Westbere, a shallow well [TR 1885 6173] 370 m ENE of Stonerocks Farm proved 1.2 m of brickearth to overlie gravel seen to a depth of 3 m from the surface. Brickearth capping the gravel in workings [TR 1910 6175] within 230 m E of this point (see p.70) proved to be a heavy clayey deposit about 1.5 m thick, locally very stony and having a distinct clay seam at the base.

A little brickearth fringes gravel at the edge of the plateau just northward of Westbere church. At the top of the sand-pit [TR 1927 6130] 230 m N of the church some 3.0 to 3.7 m of brickearth, with a gravelly base, appeared to pass into gravel northwards; but it is probable that the deposit may have moved a little southward and eastward from a somewhat higher level during a subsequent period of denudation when the escarpment of Tertiary beds along this side of the Stour valley became indented.

Patches of brickearth border the gravels south-east of Breadland Farm and about 0.8 km to the east-north-east of that place.

Between Broomfield and Beltinge there is an extensive spread of brickearth, mainly well above 30 m OD, which rests partly on gravel and partly on London Clay. It is typically a heavy clayey loam, scattered locally with flints and pebbles, but it gives rise to a soil much less intractable than that of the London Clay. Brickearth was exposed intermittently both along the railway southward of Beltinge and in cuttings along the main Coastal Road running parallel with this.

On the coast there are three patches of rather gravelly brickearth above 30 m OD at the top of Beltinge Cliff, the middle one of which extends to a depth of 3.7 m where its eroded edge [TR 1951 6840] was seen in the cliff.

About 0.8 km eastward of Oldhaven Gap, of three very small cappings of brickearth on the cliff, at about 24 m OD or lower, only the most westerly one is large enough to be shown on the map. The deposits here are of special interest, however, because of flint implements associated with them. The maximum thickness of brickearth is about 3 m, with a gravelly base from which Burchell (1924, p.207) has described a 'Chellean' implement found in situ. Burchell recorded the following section (about 1100 m west-bysouth of Reculver church):

Prestwich (1865, p.254) recognised that flint implements found on the shore may have come either 'from a clay drift or from the gravel which caps the cliffs', but earlier (Prestwich, 1861, pp. 364– 365, fig. 2) he had described at the top of the cliff, a 'pebbly clay deposit of small extent and about 8 feet (2.4 m) thick', believed to be of fresh-water origin, to which he inclined to refer the flint implements. This bed is indicated approximately at the position of the present isolated small patches and at that time was evidently less denuded by coastal erosion. The apparently early Acheulian type of artifact figured by Evans (1897, p. 615) was one found by Prestwich on the foreshore westward of Reculver and may well have been derived by erosion from brickearth of the 2nd Stage at this locality. SCAH

River Gravels, Third Terrace

Ipswichian

In the original one-inch survey the types of gravel were not differentiated. Until extensively worked in comparatively recent years, moreover, the terraced deposits of the Stour were almost entirely covered and obscured by later head deposits, largely the Head Brickearth of the 3rd Stage (see (Figure 8)). In the present area typical markedly cross-bedded and well-sorted sandy gravels, sharply benched into or cutting through the Tertiary beds, appear to be confined to the valleys of the Great and Little Stour.

Deposits of the Third Terrace, the base-level of which lies at about 18 to 21 m above OD, are more or less confined to the neighbourhood of Sturry. It is significant to note that the gravels are some 9 m thick and that their upper surface may reach nearly to 30 m OD. Deep quarrying has, however, practically worked out the deposits, which were dug in several large pits until an abrupt wall of Tertiary beds was reached. On excavating north-north-westwards large rafts of London Clay or detached masses of pebbly Oldhaven Beds, for instance, were found more frequently in the gravel as the nearly vertical Tertiary surface was approached:

It was from these Third Terrace deposits of the Stour that the bulk of the palaeoliths collected by Dr Ince were obtained. The three terraces correspond to those indicated by Dewey (1925, p. 278). There are many descriptions of the Stour gravels by Dewey and Smith and others, which within the Faversham area refer entirely to Third Terrace deposits (with overlying head) and the implements found therein. Reference to these is made in the detailed descriptions below.

The period of deposition of the gravels encompassed variations of implement cultures from Acheulian types to Levalloisian industries that may locally have been contemporaneous with the later Acheulian. SCAH

Details

On the left bank of the Stour the first indications of river gravel on the Faversham (273) Sheet were noted on a spur between two hollows occupied by tongues of brickearth at a point 550 m W of Sturry Station. In a small pit [TR 1717 6051] 2.4 m or more of bedded sandy gravel were seen to be overlain unevenly by a thin coarse gravelly head.

The gravel extending on either side of the Herne Bay road at Sturry was extensively exposed in deep workings. The excavations on the west side of the road were the last to be made and the pit was still in work in 1946. As digging of gravel and its overburden extended northward into the hillside an increasing amount of drift was exposed. The final section [TR 1756 6080] on the north, near the limit of the gravel spread, was as follows:

The upper group of river deposits appears to contain a good deal of Tertiary sand and clay derived from the immediately adjacent solid formations either by river erosion itself, or by sludging into water, or by aeolian agencies. Numerous palaeoliths have been found in this pit (e.g. by Dr A. Bowes, of Herne Bay) subsequently to the published accounts which refer mainly to Dr Ince's collections from the earlier pits to the eastward.

The pits east of the Herne Bay Road as far as the road to Hoades Court were thoroughly described when they were being actively worked many years ago (Plate 6). The fullest account, including details and illustrations of the palaeoliths, was by Dewey and Smith (1925, p. 117), who quote the names of the pits (mentioned below) and indicate their locations (see pp. 132, 133). Dewey also separately summarised the geological results and conclusions on dating the deposits from the archaeological evidence (Dewey, 1925, p. 279; 1926, p. 1430). The data were again recapitulated in the British Museum Stone Age guide (1926, p. 37). Sections in these terrace deposits are illustrated in great detail by Breuil (1934, figs. 23, 24). They show the great variability of the gravels, but the emphasis placed on solifluction levels and their supposed equivalent continental glacial phases cannot be substantiated in detail; the Head Brickearth of the 3rd Stage, which is a later heterogeneous deposit overlying the whole series of river drift, is the significant drift of non-fluviatile origin (see p.92) that can be separated and mapped over a wide area. Sections in all the pits in this tract have a general resemblance and show a basal bed of clayey or loamy gravel overlain by a sandy manganese-stained band and then a thick development of cross-bedded gravel and sand with included masses of earlier-formed deposits. Over these lie accumulations of brickearth and wash of much later date.

'Homersham's west pit' [TR 177 607], less than 0.4 km N by W of Sturry Station, had become degraded by 1946 and exposed only some 3 m of well-bedded gravel, with numerous sandy lenses containing chips of flint. From these beds the overlying uneven head brickearth, with associated head gravel, had been mostly dug off. Originally some 10 m of gravel and sand were to be seen and it was here that the greater part of Dr Ince's detailed collecting of implements was carried out as digging proceeded, the finds being most carefully related to horizon and position in the gravels. At the base, resting irregularly on the Woolwich Beds, was a ferruginous even-bedded gravel with unrolled hand-axes described as early Acheulian (examples are M.I. 25551, 25552 and 25556–8 in the Geological Museum collections) but in the middle of the sequence, in markedly cross-bedded gravels and sands, were flakes and hand-axes (e.g. M.I. 25549, 25550 and 25555), and 'tortoise-cores', which would later probably have been considered a Levallois culture. Near the top of the river gravels rolled hand-axes of the older 'Chellean' and Acheulian types occur. Their presence in these later deposits, however, is understandable enough, for they were evidently washed into the gravel and sand from adjacent higher ground; they had escaped the river waters until the last phase (Acheulian–Lavalloisian) of the great period of deposition represented by the Third Terrace gravels, having long lain either on an old land surface or, especially in the case of the more primitive implements, been contained in the older high-level deposits of the Blean. There is in fact no anomaly in the mixture of artifacts of various types and ages at any particular level in the gravels, a feature which was found somewhat puzzling when detailed studies of the Sturry deposits were first begun. It must also be borne in mind that 'Chellean' types are now known to persist in association with the more advanced Acheulian types of implements, so that the amount of their abrasion may indeed be the clearest guide to the ag e of the former. The basal 1 to 2 m of gravel is clayey and overlain by a black manganese-stained band, while the overlying gravels are coarse and uncemented. When traced southward, first the basal gravel and then a large proportion of the higher beds were formerly seen to thin out and disappear against a rising floor of Woolwich Beds. On or near this surface were discovered implements described by Dewey and Smith both as Acheulian and Chellean forms, the latter perhaps being derived from the same ancient land surface or deposits as those which later found their way into the Third Terrace gravels near their top. Apart from flints of many kinds, mostly well-worn, the gravels contain Tertiary pebbles, lumps of Lower Greensand ironstone, silicified wood and occasional 'sarsen stones', or fragments of these, presumably derived from nearby outcrops of Thanet Beds, where they probably occurred as concretionary doggers.

From a small cutting just south-east of Homersham's west pit 113 implements were obtained from the 1.2 m of gravel present before the whole series thins out on the south and east against Woolwich and Thanet beds. Of these, 64 came from red gravel at the base and 24, including relatively advanced types, such as a pointed Acheulian hand-axe, from bedded gravels above.

'Homersham's east pit' [TR 178 608] was immediately adjoining their west pit on the north-east side and subsequent working eventually connected the two. Formerly the pit exposed on the south some '17 ft (5.2 m) of strongly current-bedded sandy gravel, the base resting in channels cut in the Thanet Sand' (Dewey and Smith, 1925, p. 132). The Tertiary sand here and in the west pit is now classified as Woolwich Beds. In this pit southward-coursing gullies which cut through the cross-bedded gravels were at one time to be seen. Filled with crudely-bedded sand and gravel, one of these was measured about 6 m wide.

A steep narrow valley which indents the Tertiary escarpment separates these gravels from a further spread in which the pits known as 'Ashenden's' were dug. The small sand-pit [TR 1784 6072], 320 m NNE of Sturry Station showed, above the Woolwich Beds (p. 36) about 2.5 m of cross-bedded sandy gravel with lenses of sandy loam or brickearth. Near the base, where drift interdigitates irregularly with the sands below, are lumps of ironstone derived from the Woolwich Beds. The adjoining disused gravel pits [TR 179 608], about 0.4 km NE of Sturry Station and approximately corresponding with Dewey's 'Ashenden's west pit', exposed some 2.4 to 3.7 m of similar cross-bedded gravels cut occasionally by channels of rougher coarse gravel seen in the south. These gravels again rest on Woolwich Beds, but the masses of dislodged clay noted by Dewey (1925, p. 279; in Dewey and Smith, 1925, p. 120) and considered by him to afford evidence of transportation under arctic conditions cannot have come from the Woolwich Beds, which in this area are now known to be essentially coarsely sandy. These masses probably consisted of foundered basal London Clay derived from the immediately adjacent erosional cliff which bounded the terrace deposits on the north-west (later to become degraded and buried beneath head brickearth). The Acheulian implement figured in the Antiquaries Journal, Vol. ix (1929, p. 244) appears to have come from this pit. The disused 'Ashenden's east pit' [TR 181 609], adjacent to the preceding, was excavated in gravel at the eastern limit of the spread under consideration. Former sections here were studied in some detail by Dewey and Smith (1925, p. 132). The cross-bedded gravel and sand included a number of 'boulders' 0.6 m in diameter of hardened sand that appeared to have a common origin with the compacted masses of gravel (containing 'Chellean' implements) seen in other pits. They were probably eroded and disturbed penecontemporaneously. In a part of the pit which exposed 4.6 m of gravel and sand with a manganese-stained layer the Woolwich Beds were not reached. 'Chellean' and Acheulian artifacts were obtained here, and from another spot a flake of Levallois type. There was a sharp distinction between unworn hand-axes and the ones that were water-worn: all the latter apparently came from disturbed gravels in the higher parts of the deposit.

Another small valley isolates a further patch of gravel, situated about 0.8 km NE of Sturry Station, in which only overgrown small sections were to be seen; but farther east beyond a third steep valley there is separate gravel which was formerly worked at 'Dadd, Neville and Cooper's pits' [TR 185 611], in Hoades Wood, nearly 1 km NE of Sturry Station. In 1946 much of the gravel had been dug off but on the south the remaining gravel was seen to overlap from Woolwich Beds on to Thanet Beds and to include in a coarse basal gravel at about 2.4 m depth not only 'nests' of pebbles from the Oldhaven Beds (which 'backed' the terrace on the north) but also blocks of the characteristic purple iron-sandstone which derives ultimately from the Woolwich Beds, via Oldhaven Beds (see p. 32). The following section and details are abbreviated from the account given by Dewey and Smith (1925, p. 133):

Chert and ironstone from the Lower Greensand also occurred. 'Chellean' and ovate hand-axes and part of an elephant tusk were obtained from a layer about 4 m down.

The last patch of Third Terrace Gravel seen during the survey was just beyond a fourth narrow valley at the road to Hoades Court and situated on the hillside at the junction of the road from Westbere with the main road to the Isle of Thanet. A very small pit [TR 1861 6103] on the north-west side of this main road showed 1.8 m of gravel with cross-bedded sandy seams, overlain by head brickearth. SCAH

River Gravels, Second Terrace

Ipswichian

The deposits of this stage correspond with the Middle Terrace of Dewey which near Canterbury has a base level of about 10 m above OD. Beyond Sturry, where they lie at approximately 7.5 m OD, their 'level falls noticeably to about 4.5 m OD at Stodmarsh and probably less than 3 m OD at West Stourmouth. A similar fall may be traced along the east bank of the Little Stour, where from a height of about 7.5 m OD at Preston Court the gravel falls rather more rapidly to about 1.5 m OD 0.4 km NW of Preston Street. The gravels are only locally present at the surface because they are very largely overlain by Head Brickearth or Head Gravel of the 3rd Stage, but they probably extend laterally beneath the head drifts in some cases and there may well exist undetected patches of river gravel which are completely obscured by the later drifts. These terrace gravels are not more than about 4.5 m thick.

The molluscan fauna discovered in deposits at Preston affords good evidence for correlating the Second Terrace drift with the Crayford stage in the Thames valley (see p.63). The Preston gravels are the only deposits of this terrace which have been extensively worked, but old sections near Grove Ferry and Wear Farm, Chislet (see pp. 77–78) have also yielded Corbicula fluminalis and other shells from similar beds covered by later drift.

According to Dewey (1925, p. 282) late Acheulian implements have been found at the base of gravels of the Middle Terrace between Sturry and Canterbury; and near to Canterbury derived worn 'Chellean' hand-axes also occurred. Comparison with the Crayford drifts suggest that Acheulian cultures may have locally given place entirely to Levalloisian during the period represented by these gravels. SCAH

Details

At Sturry there are two small areas where gravel forms gently rising ground without cover of overlapping brickearth; these are around the station and some 275 m westward of it, and are the only patches to be seen on the left bank of the Stour.

A ridge of gravel at Puckston Farm, west of Stodmarsh, is presumably of the same stage. Trial holes proved this gravel to extend eastward under the Head Brickearth which overlaps it. Gravel also occurs at the surface south-west of Stodmarsh church and is known to extend northward beneath brickearth which is some 1.5 m thick at an overgrown pit [TR 2195 6068] 110 m NW of the church. East of the tributary stream at Stodmarsh sandy river gravel, probably to be classed with the Second Terrace, appeared to be present 1.2 m down, beneath clayey Head Gravel, in an excavation [TR 2219 6076] dug 250 m NE of the church. A similar occurrence was suggested in a pond section at Newborns Farm, over 0.8 km to the north-east.

At West Stourmouth an old pit [TR 2560 6285] adjacent to the church showed gravel, probably part of the Second Terrace, underneath thick brickearth.

The most southerly gravel near Preston which is referred to river origin was seen in old pits at Preston Court. Bedded fine gravel, with lenses and seams of coarse sandy brickearth containing chips of flint, occurs beneath gravel and brickearth of head origin which have been largely removed in working. The southern boundary of the terrace deposit appears to be sharply defined against Woolwich Beds (overlain by Head Gravel). Whitaker (in MS) described the section as it appeared in 1865; all but the top beds he classified as 'River Drift', which consisted of 'whitish soft marl, with a few flints and pieces of shells', up to 0.9 m thick, resting on a foot of brown sand (derived from the Tertiary beds) which lay on gravel consisting of 'chiefly subangular flints, but some flint pebbles', resting on Woolwich Beds. Within 0.4 km NNE further gravel forms a flat terrace bordering the Head Brickearth.

The gravel 0.4 km NW of Preston Street was worked only on a small scale until later years, when removal of brickearth overburden enabled the whole main bulk of the terrace gravels to be worked out. The pits are now disused, but sections [TR 250 616] were seen in the workings on the north-east, within 550 m northward of the inn, in 1946 and 1951. The following is a summary of the full sequence of drifts:

The shells were identified by Dr J. W. Jackson. They indicate a fairly swift-flowing river which carried muddy sediment at times. The climate was probably moist and warmer than at the present day. The presence of land shells may indicate either flooding or considerable foundering of soil into the river at its eroded bank. Mammalian remains and human artifacts have been reported from the gravels. The terrace is sharply bounded by a wall or cliff of Tertiary beds beneath Head Brickearth, apparently on three sides: the north, the east and the south.

On the left bank of the Great Stour there are degraded hollows indicating the sites of several old gravel pits northward of Grove Ferry Station. Of special interest is the description of a 'section opposite the Grove Ferry Station near Canterbury, Aug. 1855' recorded, in MSS in the Geology Library, British Museum (Natural History) p.59, by John Brown (see also pp. 52–54) for there is strong indication of a river deposit beneath the Head deposits at this point and the presence of Corbicula fluminalis and Hydrobia radigueli points to Second Terrace age. The following is an interpretation of Brown's section:

Probably the river deposits were worked out to the inward limit of the terrace at an early date. Further non-marine mollusca from Grove Ferry were listed by Kennard and Woodward (1901, p.241), and it is probable that Brown collected them all from the same general locality. They include species of the land forms Helix and Limax and possibly Valvata piscinalis. The presence of Limopsis (see p.53) (indistinguishable from L. aurita from the Coralline Crag) is now possible to explain; the shells appear to have been associated with a dark ferruginous sandy nodule which could have been transported far by river agency. The occurrence of Balanus compares significantly with fossils from Wear Farm, Chislet and indicates proximity to the sea at some stage.

River deposits possibly occur beneath the Head Gravel at Chislet village (p. 82) and have been proved to underlie the Head Brickearth to the south-east of Wear Farm. Sections in the old pit [TR 2242 6500] 270 m SSE of the farm were described by Prestwich (1855, p. 111), Dowker (1864, p. 341), Brown (in MS) and Whitaker (in MS), and a fauna of non-marine mollusca, from old collections, was listed by Kennard and Woodward (1901, p.241). Evans (1897, p. 620) emphasised the significance of the deposits and their fauna, which had been described by Prestwich, who saw 0.9 to 2.4 m of 'gravel, flint-rubble, and brickearth' resting on 2.4 to 3.7 m of 'light quartzose sand, with seams of fine flint-gravel, in some of which shells are numerous'. In the lower part were layers of laminated clay with vegetable material and a band of large angular flints rested directly on the Chalk. Dowker's section appears to apply to the same pit, for the one 'on the other side of the road' showing a greater thickness of head overlying Thanet Beds and Chalk (p.29) is not in fact the pit the account of which he ascribes to Prestwich. John Brown's section, from his MSS in the Geology Library, British Museum (Natural History), shows very clearly that the bedded shelly gravels are banked against steeply rising Chalk. W. Whitaker's MS section and notes demonstrate, too, that the deposit ends off 'suddenly westward, where the Chalk is close to the surface'. As well as Pleistocene shells he found material derived from Tertiary beds, 'small roundish pieces of chalk, flint-pebbles, and subangular flints scattered throughout'. At the base he saw green-coated flints (derived from the Thanet Beds) in addition to subangular and angular flints. Prestwich obtained a number of fossils, of which the shells occurred locally in seams of fine gravel in the lower part of the section. In addition to mammalian bones, including those of the ox, and to various Entomostraca, including opercular valves of Balanus, there were a few foraminifera and the following molluscan shells, the first three of which are represented in the John Brown Collection in the British Museum (Natural History): Corbicula fluminalis L.6734, Hydrobia radigueli G.6073, Bithynia tentaculata G.6074, Ancylus fluviatilis. All these are freshwater species and the first two are not known later in the Pleistocene than the Crayford brickearth deposits of the Thames. From specimens in the Prestwich, Brown and Kennard Collections at the British Museum (Natural History) it has been determined that shells listed by Kennard and Woodward as Paludestrina ventrosa are in fact those later ascribed to the species deani and radigueli and listed above as Hydrobia radigueli. Kennard (1944, p.147) includes Chislet in discussing the range, location and habitat of the species. The fact that it apparently preferred slow-moving water, the presence of Balanus and the ostracod Candona torrosa and the occurrence of foraminifera together suggest brackish water and estuarine conditions, at any rate for certain levels. Further shells named in Brown's MS are Valvata piscinalis, Unio, Pisidium and 'Bithinia ventricosa'. Examination of two Balanus valves (L.49185) in the Prestwich Collection has shown that, according to Dr J. P. Harding, these are more closely similar to Balanus improvisus than to other possible species. It is of interest to note that Darwin (1854, p.252) found that B. improvisus thrives not only in salt water but also in brackish or even fresh, as in the La Plata estuary; he also described it as 'commoner on the shores of Kent than on other parts of England'. If the ancient Stour estuary was established at the early date of the Chislet deposits, then occurrence of the fossil species has an added significance.

Gravel recorded by Whitaker (in MS) about 1.2 km SSE of Reculver may be a comparable river-deposit. A pit ?[TR 232 683] dug through head brickearth proved 1.8 m of regularly current-bedded drift, with foresets lying at about 10° eastward, consisting of loose sandy gravel 'made up chiefly of pebbles, but also with subangular flints, the stones mostly of the same size throughout', resting on sand of the Thanet Beds. SCAH

River Gravels, First Terrace and Buried Channel Deposits

Ipswichian/Devensian

The deposits grouped under this heading correspond with the gravel of the Lower Terrace described by Dewey (1925, p. 282) near Canterbury, where 3 to 6 m of gravel (beneath brickearth) rested on Thanet Beds at about 0.9 to 4.0 m below OD. The gravel was in the present area only seen at Sturry, where it was uncovered [TR 1805 6025] about 320 m SE of the station by removal of Head Brickearth and farther to the east dug out [TR 184 604] from below the

Alluvium, where gravel rests in channels in the Thanet Beds at about 3 m below OD. However, to judge from scanty indications in the alluvial belt, for instance near Grove, the Buried Channel deposits of both Great Stour and Little Stour generally carry relatively little gravel, and what there is probably lies in restricted channels not more than 6 m deep. East of Stourmouth there is evidence to show that stony or sandy drift or gravel occurs at depth below shingle and Alluvium in the complex estuary of the Stour at Rich-borough and Sandwich Bay. At the latter place a well proved 10.7 m of stony drift, of which probably only part is shingle; records of trial-boreholes at Stonar near Rich-borough published by Robinson and Cloet (1953, p. 74) indicate that the base of the Buried Channel is cut down to 15.8 m below OD: recent geophysical work has proved its seaward continuation under the Goodwin Sands (B. D'Olier, personal communication). Independent information on the thickness of Alluvium (p.94) confirms this approximate depth for the Stour deposits, which are likely therefore to extend to an intermediate figure of some 10 m below OD about Stourmouth.

Gravels of the First Terrace and Buried Channel have not yielded implements, but according to Dr A. Bowes a tusk of Mammuthus primigenius and a horn of Bos primigenius in the Herne Bay Museum were obtained from the buried channel of the Stour between Sturry and Canterbury. SCAH

Details

Dredgings [TR 184 604] within 0.8 km ESE of Sturry Station brought up sand and gravel, as well as sandy clay and loam with flints embedded in it. Gravel was believed to occur in channels cut into the 'bungum' or grey clayey sand of the underlying Thanet Beds, and was 1 to 3 m thick.

If gravel of the First Terrace borders the Stour in its lower reaches it is nevertheless obscured by Head brickearth or by Alluvium which was the result of drowning the valley during a later period of subsidence. SCAH

More recently there have been extensive gravel excavations south-west of Sturry. A pit [TR 168 594] on the adjacent Canterbury (289) Sheet, 'Stuffy Quarry', showed the following section in 1976:

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WOLDSTEDT, P. 1951. Das Vereisungsgebiet der Britischen Inseln and seine Beziehungen zum festlandischen Pleistozan. Geol. Jahrb., Vol. 65, pp. 621–640.

WOOLDRIDGE, S. W. 1928. The 200-foot Platform in the London Basin. Proc. Geol. Assoc., Vol. 39, pp. 1–26.

WORSFOLD, F. H. 1926. An Examination of the contents of the brickearths and gravels of Tankerton Bay, Swalecliffe, Kent. Proc. Geol. Assoc., Vol. 37, pp. 326–339.

ZEUNER, F. E. 1958. Dating the past. An introduction to geochronology. 4th Edition. (London: Royal Society.)

ZEUNER, F. E. 1959. The Pleistocene Period. Its climate, chronology and faunal succession. (London: Hutchinson.)

Chapter 9 Pleistocene and Recent (Continued)

Younger Head Gravels

Ipswichian/Devensian

The gravels of this 3rd Stage are distributed predominantly in the valleys or on their sides; but they tend to lie on an undulating surface of solid rocks and in fact form an intermittent though fairly extensive mantle to a topography already matured in late Pleistocene times. Where spreads have been subsequently dissected, as at Oare, Faversham and Preston, they may locally have the appearance of terraces, in some cases lacking any contact with head brickearth; they suggest a date somewhat earlier than the gravels which mantle the valley sides and always make contact with brickearth, which overlies them and is of post-First Terrace age (see p. 83). In general, however, it is the intimate relationship with the subsequent Head Brickearth of the 3rd Stage that is specially characteristic of these gravels. It is therefore only possible to describe the gravels separately from the brickearth in those areas where they present distinct tracts either free from brickearth or from which the latter has been dug off. For localities, e.g. at Swalecliffe, where gravels are closely intermingled with brickearth, either as beds or lenticles, it has been necessary to describe the whole series of deposits together under Head Brickearth, 3rd Stage.

The gravels appear to have been laid down at first rather intermittently and locally until a time when erosion, already noted (p. 68) as affecting the Intermediate Head Gravels, tended to dissect them. This erosion was probably controlled by the cutting down of the Stour to First Terrace level. Some indications of the age of these earlier accumulations of Younger Head Gravels may be gauged from the presence of Palaeoloxodon antiquus, which became extinct at the end of the last (Ipswichian) interglacial period; it occurs in the older stony drift on the west at Swalecliffe (see p. 90). There followed a period of more continuous accumulation of head gravel which produced, for instance, the compact unbedded gravels near Oare and Faversham which have yielded remains of mammoth, horse and Bos sp.Finally came phases of alternating gravel and brickearth accumulation which formed a transition to the dominant deposition of head brickearth which overlies and overlaps the gravels. To judge from the evidence of implements associated with both gravel and brickearth at Hoath (p.92) Acheulian styles of implement manufacture still obtained at this late period of time.

Gravel of this stage usually occurs in spreads about 3 m thick but may be much thinner where it is interbedded with brickearth. It is normally a very compact gravel composed of battered but largely unrolled flints from the Chalk, with a matrix of angular flint chips and coarse-grained sand, and including a proportion of small pellets of chalk. Other constituents vary considerably according to local sources of material upon which the drift rests; such are green-coated flints near outcrops of Thanet Beds, pebbles derived from Oldhaven and Woolwich beds and an admixture of clay in the matrix where the drift lies against London Clay. Some blocks of sarsen stone probably came from the Thanet Beds but in addition to material from Tertiary sources there are lumps of ironstone which have been derived ultimately from the Lower Greensand, via older drifts. Relatively few brown-stained flints occur in the head gravel.

A lack of either sorting or bedding, except in the crudest sense, is characteristic of the gravel. There are occasional seams or lenses of brickearth or coarse-grained sand but these are commonly very irregular or considerably contorted. The general absence of bedding or particle-sorting points to an origin by solifluction processes that were modified by perennial melt phases. The broadly undulating base of the drift, which covers low hills, valley sides and valley bottoms without noticeable variation in thickness, e.g. between Oare and Faversham, is also difficult to explain in other ways, and this contrasts very markedly with the terraced gravels of the River Stour. Furthermore, the bulk of the constituents of the gravel could not have travelled far and have retained both their angularity and their close relationship to adjacent sources of supply. SCAH

Details

In the Isle of Harty a patch of small gravel with pebbles and sand slopes eastward, at about 7.5 m OD, approximately 0.5 km ESE of Sayes Court. This is the only gravel shown on the map, but thin drift, in pockets or impersistent spreads, also occurs on rising ground at Sayes Court and westwards, southward of Mocketts and 0.8 km W of Elliotts. The well [TR 0227 6631] at Sayes Court proved the London Clay to be covered by 0.6 m of gravel underlying 1.8 m of clayey drift and soil, material which deceptively may resemble undisturbed London Clay. The valley west of Judd's Hill, west-south-west of Faversham, has a mainly gravelly floor (as seen in old pits) flanked on either side by brickearth. The gravel contains many large irregular Chalk flints and includes a variable amount of brickearth matrix. Similar gravel occurs in the valley east of Judd's Hill but rapidly merges northward into brickearth. Gravelly loam on the left side of the stream at Ospringe was proved in trial holes to be more than 1.8 m thick and to extend beneath the alluvium of the stream. A deep boring just south of the boundary of the map proved more than 3.7 m of drift overlying the Chalk.

Northward of the railway an extensive tract of gravel trends towards Oare; it is exposed at the surface largely as a result of the removal of much brickearth for brickmaking. Whitaker (in MS) noted that in the railway cutting (north-east of Judd's Hill) the junction of brickearth and very coarse flint gravel, both 2.1 to 2.4 m thick, rises and falls with the ground. The two outlying spreads of gravel about Davington Hill, which are separated by bare Thanet Beds around Davington Church and Priory, lie at about 15 m OD on the south-west and at about 12 m on the northeast, where gravel was at one time dug to 1.8 m. Hughes (in Whitaker, 1872, p.80) implies that the gravel may be somewhat older than that directly associated with the brickearth. The latter gravels have been extensively exposed from time to time where both gravel and brickearth were dug westward of Davington Hill. On the south-west, towards the railway, gravel was absent at one point, where brickearth rested directly on Thanet Beds; these conditions are exceptional, however, and in the centre of the main spread sections seen in 1938 may be generalised as follows:

Bones of mammoth are said to have been found hereabouts. The gravel descends without interruption into the floor of the valley below 15 m OD on the north-west, where in 1951 brickearth was removed and the gravel dredged down to the underlying sand of the Thanet Beds. SCAH

More recent excavations [TR 002 620], noted in 1976, showed the following section at the southern end of the working:

In the remaining areas, north-west and north-east of Davington Hill, gravel shown on the map appears only as a result of removal of brickearth. SCAH

The southern end of the Oare quarry [TR 014 625] exposed the following section in 1976:

The Head Brickearth thickness varies from 1.5 to 5.0 m in this working. RAE

Between 0.4 and 0.8 km ESE of Oare ballast was dug from beneath the Alluvium and adjacent to it. More than 1.8 m of unsorted gravel contained many large abraded but irregular and unrounded Chalk flints and some large boulders of sarsen stone. In the gravels occur bones of horse, ox and mammoth, and also shells such as Ostrea bellovacina and Cucullaea decussata derived from the underlying Thanet Beds.

The spread of gravel which extends through Oare is at 24 m OD on the south-west but at 12 m OD or less near the village, where formerly it was dug after removal of brickearth. An old pit [TR 004 627] just south-west of Oare exposed some 2.4 m of coarse gravel with a sandy matrix, including contorted and crudely stratified sandy lenses and seams. In addition to large bluish battered Chalk flints there are green-coated flints (from the base of the Thanet Beds), black and brown Tertiary pebbles (derived from nearby Oldhaven Beds), fragments of ironstone and sarsens. Whereas on the northwest this tract of gravel gives place to brickearth, on the south-east side subsequent erosion has exposed a bank of Thanet and Woolwich Beds, upon which rested 1.8 m of ferruginous subangular gravel with large irregular flints in a small exposure [TR 0071 6320] about 275 m northward of the cross-roads at Oare. About 45 m NW of this section at [TR 0067 6323] 3 m of crudely bedded drift included gravel interbedded with sandy brickearth and sand with lines of white chips of flint, overlying Woolwich Beds.

Three small patches of gravel with Tertiary pebbles occur around 0.8 km WNW of Court Lodge but the gravel associated with the brickearth 0.6 km NNE of that place is less pebbly. The gravel resting on London Clay and Oldhaven Beds at the edge of the Alluvium eastward of Uplees has both clay and sand in its matrix and was up to 2.1 m thick in a series of small exposures. Besides the normal rough whitish subangular flints there are scattered ochreous flints, a few bits of ironstone and Tertiary pebbles in quantity. SCAH

In 1976 this working [TR 004 644] showed the following section:

Eastward of Faversham there are no Younger Head Gravels present, apart from gravels in or below the brickearth, until the Stour valley is reached, and their occurrence in that region is always closely connected with the brickearth of the 3rd Stage.

There are small areas of gravel in the valleys, on the north side of the brickearth, 0.4 km south of Tyler Hill and 180 m ENE of Britton Court Farm, where about 1.5 m of subangular gravel with pebbles in coarse-grained brown clayey sand was formerly dug [TR 1437 6179].

Small tracts of gravel were differentiated from the brickearth at four localities on hill-slopes north-west of Sturry. These are above the sand-pit on the road to Broadoak, at the southern edge of Den Grove Wood (very coarse rough gravel with sand, loam and clay) and on the north and south sides of the large gravel pit on the west of the Herne Bay road, where up to 1.5 m of rough gravel is at 38 m OD descending to 15 m OD.

At Grove Ferry the head gravel is clayey and over 3 m thick and at Upstreet Farm old pits [TR 2342 6348] in the same spread were dug to 3.7 m. At Chislet village gravel is at the surface but a well-section at the school just south-west of the church indicated 7 m of interbedded loams and gravels, according to MS notes by Whitaker. Probably the gravel seen 0.8 km W of the village, 1.2 km NW and 0.5 km NNW is also closely associated with the large spread of Head Brickearth of the 3rd Stage which mantles drift and solid hereabouts.

Younger Head Gravels are distinct from the brickearth on the western slopes between Grove Hill and Stodmarsh. An excavation [TR 2219 6076] 250 m NE of Stodmarsh Church proved 1.2 m of unbedded and unsorted gravel, in a coarse-grained impure sandy matrix, with large battered irregular flints, small chips of flint and Tertiary pebbles. A small tract of similar gravel is present at Newborns Farm.

Near Preston the gravels are also to be found on the western side of brickearth-covered slopes, but a fairly steep bank separates them from the Alluvium of the Little Stour and their western margin is dissected. These facts, together with their position between underlying Second Terrace Gravel and the Head Brickearth of the 3rd Stage, which overlies and overlaps them, indicate that they were deposited at a date probably somewhat earlier than the lowest terrace gravels of the Stour. They are thus older than the similar gravels near Stodmarsh. Their thickness is about 1.5 m as exposed in several small degraded pits. The best sections seen were in the old gravel workings [TR 2428 6052] at Preston Court, where unsorted gravel of mainly white flints, with some Tertiary pebbles and worn ochreous flints, lies irregularly, with a maximum thickness of 1.8 m upon river gravel (p. 77). SCAH

Head Brickearth, 3rd Stage

?Ipswichian/Devensian/Flandrian

The greatest proportion of drift which is at the surface in the Faversham district consists of this brickearth. It occupies valleys, mantles their slopes or forms a cover to gently undulating ground. Its relationship to other, older, drifts is twofold. The Younger Head Gravels are part of the same series and where they are in contact with the brickearth a passage, with interbedding of the two types, is sometimes to be seen. All other drifts that underlie this brickearth, however, are traversed unconformably by it, particularly the River Gravels of the Stour valley (see (Figure 8)). Like the Younger Head Gravels, which the brickearth frequently overlaps, the drift is related to a topography of late Pleistocene time which has persisted with but slight modification to the present day. The most extensive spreads of the deposit are around Faversham, Sturry, Stodmarsh, Preston, Chislet and Herne Bay but it also occurs in deep valleys which cut into the London Clay of the Blean and in relics of similar valleys on the northern coast of the Isle of Sheppey. Mr P. E. Harding was able to distinguish some spreads and narrower tongues of this brickearth between Sarre and Potten Street on the Isle of Thanet; contiguous deposits are extensive over most of that island.

The brickearth attains a maximum thickness of some 6 m where it occupies deep hollows and valleys, as at Swalecliffe and north-east of Sturry, while in the Blean valleys generally it varies from 1.5 to about 4 m. Some 2.5 to 3 m is a general thickness for the broader spreads, e.g. around Faversham and Preston, but deeper hollows of drift may occur.

The deposit is essentially a compact but porous, yellowish brown loam, more or less homogeneous, which breaks or cracks in an even columnar manner but is otherwise structureless (Plate 7). It frequently contains minute cylindrical hollows taken to represent the positions of rootlets or root hairs but those features are absent in the heavier, clayey, types. On rare occasions the brickearth may show signs of lamination, for instance in grey streaky sandy clay at Swalecliffe and Hampton. A feature which is applicable particularly to the Head Brickearth of the 3rd Stage is its variability according to the nature of formations upon which it rests, i.e. predominantly a variation in the clay content which is always present. Whereas in Chalk and Tertiary sand areas the brickearth tends to contain pellets of chalk or to become rather strongly sandy, on the London Clay it may comprise so much stiff clay (of a similar chocolate hue) as to be almost indistinguishable from the solid formation in its slightly weathered state, as was demonstrated in the narrow valley south-east of Whitstable. It is not unlikely that some drift in other deep London Clay valleys may, in fact, have remained undetected. These similarities are particularly true of the basal beds but the latter also may provide the necessary clue to their drift origin by the inclusion of interbedded gravelly seams. On occasions a rough stony brickearth may interdigitate at its base with the reworked bedrock or the junction may be contorted or festooned by cryoturbation. Near Faversham some of the brickearths are practically the fine-grained clayey sand of the Thanet Beds re-deposited with slight additional material; but these also commonly have a gravelly base, sometimes including boulders of sarsen stone, or contain gravelly tongues, lenses or rafts. The Head Brickearth may also contain scattered unworn flint nodules, occasional Tertiary pebbles, thin lines of white flint chips or of chalk pellets and lines of calcareous nodules or 'race' (notably at Preston and at Hampton). At Faversham excavations have shown that the latter form a local basal seam to a pale sandy brickearth with shell fragments (p. 89). In places darker brown loamy sand may diversify a little of the brickearth or the deposit as a whole may appear orange-brown or purplish rather than yellowish. Relatively abundant Tertiary pebbles in the Sheppey brickearths were probably derived via older drifts. A similar derivation may explain the presence of worn ochreous flints elsewhere.

The origin of the brickearth in north-east Kent is discussed in the memoir on the Chatham district (Dines, Holmes and Robbie, 1971, pp. 110–114). As remarked by Smart (in Smart and others, 1966, p. 212) the deposit can result from several terrestrial processes, of which the most important may be solifluction as the main transportive agent. Smart has also noted (in Smart and others, 1966, p.213) that London Clay can weather under suitable conditions to produce a heavy brickearth; in the Canterbury district, as near Faversham, 'such brickearth is associated with landslipped London Clay, and is perhaps formed by intense frost action upon landslipped material'. It is unlikely that there is much brickearth of predominantly aeolian origin in the Faversham district other than that referred to the oldest group or 1st Stage. Very little was laid down in water, for the shells of non-marine mollusca found in it are practically all land forms, though many are marsh-loving. An exception is a late Quaternary deposit at Faversham, recorded by Trimmer (1851, p. 36), which apparently passes below sea level and may perhaps be considered as a lacustrine equivalent to an early alluvium (see below). Another special case is a flat of very clayey brickearth at Dargate Common (p. 89) which has some of the characteristics of a high-level alluvium and was probably accumulated as a sludge of eroded London Clay slipping from surrounding high ground into a lake which eventually found an outlet on the north-west. The brickearths of the Faversham district are nowhere part of the sequence of terraced river deposits and their distribution is in no way controlled by them.

In their useful summary account of Head Brickearth in north and east Kent, McRae and Burnham (1973, p. 34) draw attention both to the early notice by Prestwich (1865) of the similarities between brickearth and loess and to some relevant recent researches at Pegwell Bay, on the east side of the Isle of Thanet (Weir and others, 1971). Though in general Head Brickearth can conform closely to true loess, for example, in particle size distribution, and the mineralogical composition, particularly of its silt fraction, and may suggest an origin from the glacial tills of East Anglia, in the Faversham area much more than the typical 10 to 20 per cent is of local provenance and the stone content can be high. It is therefore difficult to regard the deposits of the 3rd Stage in that area as having originally a wind-blown origin; perhaps strong aeolian transport prevailed only along an 'East Coast' wind-flow line determined by late Pleistocene climate.

A general consideration of modes of Head deposition affords further evidences of brickearth origins: of these it would appear that solifluction under cold conditions played an unimportant part during the brickearth stages; beds of gravelly drift may represent stronger denudation during cold phases but in all cases where non-marine mollusca have been found in the normal fine-grained brickearths they indicate either a moist temperate climate or a somewhat colder but damp environment far less severe than under periglacial conditions, so that frost action could only have been intermittent. The evidence of mammalian remains is inconclusive; for whereas both 'warm' and 'cold' elements have been recorded, it is not only difficult to decide whether the bones are derived from an earlier land surface or deposit or are broadly contemporaneous with the drift in which they are found, but also the adaptability strongly inherent in mammals must be carefully considered against the background of purely geological indications or those from other faunas. It is noteworthy that the greatest numbers of mammalian bones have been found in beds of clayey gravelly brickearth at the base of the series, where the drift may be transitional from or equivalent to the Younger Head Gravel.

The studies of Godwin-Austen (1857, pp. 63, 71) on the brickearths of Sussex apply in a striking way to the Faversham deposit. He recognised a similar unconformable base, the importance of the influence of contiguous underlying strata and the evidence of land mollusca, particularly of Succinea oblonga, in indicating subaerial conditions with a moist climate. His conclusion that the most usual character of the brickearth 'is that of the wash of a terrestrial surface, under a far greater amount of annual rain-fall than we have at present' is not dissimilar to the downwash or sludge process envisaged in the formation of Head deposits generally (see Dines and others, 1940, p.206). That the climate was not necessarily a cold one must now be recognised; Prestwich (1865, p. 276) had thought that shore-ice accounted for gravelly seams in the brickearth series which he considered to be due to river flooding on a vast scale. Osborne White (1928, p. 63) ascribed brickearths in the Ramsgate and Dover area partly to 'sheet-flooding, under climatic conditions similar to but less extreme than those prevailing during the deposition of the Valley Gravel' and partly to wind action.

A marked and consistent asymmetry in the predominance of the drift on valley sides and slopes was evident in the Faversham district as was described by Holmes in 1954 at a number of locations in the Chatham area (Dines, Holmes and Robbie, 1971, pp. 112, 129, 130), where both Brickearth and Hillwash Head tend to occupy slopes on the western and southern sides of valleys rather than the eastern and northern ones, which are also generally much the steeper. In the Faversham district the similar pattern also occurs extensively both on the London Clay tracts and on the permeable Tertiary sand formations and the Upper Chalk; but any distinction there between moderate and steep slopes is much less evident, and the proportion of northerly-facing drift-mantled slopes appears relatively high, on account of the considerable easterly and westerly-trending valley components in the drainage of the area.

From a study of asymmetric valleys in the Chilterns Avery and Thomasson (1957, p. 170) were able to propound explanations for the variations of the slope deposits and their related soils on the two sides. Whatever the physical control that may have initiated differential erosion of the valleys, the amount of weathering could have been affected by insolation under periglacial conditions or by erosion in varying arid or temperate climates during interglacial phases. Thus slopes facing south-west would in a cold climate experience more frequent changes of temperature and their disintegration products would be more rapidly removed than would those facing north-east, which might remain more or less permanently frozen. Under arid or temperate conditions, however, wind or prevailing direction of rainfall could be the controlling factors. Ollier and Thomasson (1957) have reviewed the literature on asymmetric valleys in the northern hemisphere, and Thomasson (1961, pp. 297–301), describing drift deposits and geomorphology in south-east Hertfordshire, has provided a further account of asymmetric valleys that is relevant to the Faversham district. It is probable, however, that deposition of the Faversham brickearths was more or less closely interconnected with early and later phases of erosion which was certainly effected by periglacial agencies, where coarse gravelly deposits accumulated, rather than superimposed upon previously entirely river-cut slopes. Thomasson (1961, pp. 300–301) remarks on the special conditions governing the asymmetric valleys in London Clay: being uniform in texture, 'structurally controlled uniclinal shifting of streams and rivers cannot be invoked'; further, in contrast with conditions of permeability in Chalk country, 'their widespread occurrence on a normal terrain with surface water such as the London Clay raises the possibility that interglacial climates may be suitable for their formation'. In the Faversham area it seems likely that prevailing winds from the north-east both intensified disintegration and erosion of the solid formations more or less in situ and also raised dust that contributed to the slow gravitational sludge of rock-waste on easterly, northeasterly and northerly-facing slopes. As was accepted by Pitcher and others (1954, p. 313) for some of the Kentish brickearths, the deposits are by no means everywhere pure and uniform enough to be assigned as aeolian sensu stricto; consequently, it is unlikely that much of the material was, conversely, blown from the south-west and settled on the lee sides of the hills.

Smart (in Smart and others, 1966, pp. 211–213, fig. 8) was able to make a valuable assessment of Head Brickearth orientation in the Canterbury and Folkestone region from an analysis of slopes related to compass-point sectors. Here the general preference for north-east facing slopes is slightly modified, and is in contrast with conditions around Faversham, on account of the dominant north-east trending drainage pattern. The possibility that structural tilting may have affected easterly stream migration, and so encouraged differential erosion that cut more severely into the eastern and northern banks of the asymmetric valleys, for the same reason lacks direct support from the Faversham district. In both areas, however, it is clear that debris can more readily be removed by rainwash, etc., from the steeper slopes wherever the deposit is permeable and overlies permeable strata.

Much of the so-called loess of Germany is a rather heterogeneous gravelly brickearth. Pitcher and others (1954) have shown how the fine-grained structureless loess at Pegwell Bay, in the Isle of Thanet, mantles or is derived as a frost-soil from solifluction deposits; they refer to the interpretation by Zeuner of sections in northern France as evidence of the change from conditions of tundra through steppe to those of temperate forest. That a similar change took place with the transition from Younger Head Gravel to Brickearth of the 3rd Stage is very probable, but the common occurrence not only of mammals but of a large molluscan fauna precludes the view that the ameliorated climate was at those locations an arid one. Leighton and Willman (1950, p.622) state that the climate during the deposition of the loess of the Mississippi Valley varied from periglacial to temperate and that the faunas indicate rainfall and temperature adequate to support forest-type or prairie vegetation. But not all have accepted an aeolian origin for these deposits, and Russell (1944, pp. 1–40) has described a process of weathering, soil creep and colluvial transportation in the Lower Mississippi Valley which has produced by loessification' deposits which grade upslope into parent material in much the same manner as Head Brickearth grades into solid formations. The deposits also contain a similar type of 'damp' fauna of land molluscs. In Kent, however, the latter include species both Pleistocene and Holocene in age and probably the majority lived in the environment in which they are found rather than became incorporated during mass movement of the drift or were introduced into cracks as 'pseudo-fossils'. Russell also cites an example at Poppelsdorf, near Bonn, where 'the creep of loess over truncated edges of Pleistocene gravels is clearly exhibited'.

Like the 'warp' discussed by Fisher (1866, p. 562) the brickearth, though younger than the previously denuded gravels beneath or adjoining it, is for the most part older than the Alluvium. Thus, with the exception of some recent loarns which are lithologically similar to the main drift, it passes below the marsh deposits, into which its constituents have sometimes been re-worked. A section at King's Field, Faversham, seen by Hughes and described in MS notes (see p. 88, and (Figure 9)) clearly shows that the brickearth there was laid down at a date later than the disturbance of underlying Thanet Beds and Chalk by solution (itself probably determined by frost-heaving processes during a previous period of permafrost and seasonal thawing). Brickearth itself, however, is in some places affected by solution and frozen-ground phenomena which must post-date deposition at those localities. For instance, the varied brickearth deposits at Swalecliffe, on the coast, are in part considerably disturbed, and Dewey (1926, p. 1432) drew attention to the resemblance between these deposits and the Coombe Rock of Northfleet, near Dartford. He attributed the inversion and overfolding of some of the beds either to pressure of superincumbent rubbly gravel, however, or to the passage of ice across it. Solution clearly did not operate here, for the beds are underlain by impervious London Clay.

In a number of places, notably westward of Faversham, it proved possible to separate as Hillwash Head some local deposits of recent hillwash or rainwash. In the brickearthcovered areas generally there are thin surface loams of Holocene age which consist of re-worked brickearth material, indistinguishable in mapping from the older drift. In some cases the brickearth has been disturbed by human agency. Closely connected with these recent loams are the superficial accumulations of debris from minor land-slipping on London Clay slopes. This process in fact is not only to be observed at the present day but must also have been operative in varying degrees throughout the Quaternary and was an important adjunct in Head development. Every gradation occurs from bare undisturbed clay through superficial wash and disturbed ground to a distinct and continuous drift deposit. Some of the drifts described in the Ramsgate and Dover area by White (1928, p. 67) under the title 'Head' and Wash are comparable either with these loams and brickearths or with the Hillwash Head, and similarly have yielded 'mammalian remains, land-shells, and other fossils of late Pleistocene and Recent ages'.

In the succeeding details reference is made to faunas of non-marine mollusca and mammals and to some records of human artifacts. From the shells it is evident that the climate was mostly fairly warm and probably mostly very damp. From a bed in the Swalecliffe brickearth (p. 90) there is indication of a colder, more bleak habitat at one stage. The dry land was diversified with marshes, swamps and channels in some of which there was sufficient free water to give rise temporarily to lacustrine or even local fluviatile conditions. As pointed out by Prestwich (1861, p. 366; 1865, p. 274) the absence or rarity of truly aquatic shells, however, distinguishes the 'Brickearth' or 'Loess' from fluviatile gravel deposits. Both Pleistocene and Holocene shell faunas are present but the predominant assemblage is of late Pleistocene type, including abundant Pupilla muscorum and Succinea oblonga. Suggestions that much older deposits are represented, e.g. at Swalecliffe (Kennard and Woodward, 1901, p. 241; Burchell, 1954, p. 256) appear to be unwarranted. It is clear that the main shell bed at the latter locality post-dates the mammaliferous bed in stony clay which from its field relationship is recognisably older than the bulk of the brickearth. The most recent brickearths and loams include land shells and other remains of no great antiquity, such as marine shells from medieval midden material at Swalecliffe.

Mammalian bones occur in profusion in some parts of the brickearths on the coast, where they have mostly been found washed out of eroded drift amongst beach material. Others have been obtained from a few inland localities. As indicators of climate their evidence is not necessarily conclusive. Kennard (1944, p. 131) has emphasised this in stating that 'all mammals are warm-blooded and therefore prefer warmth. Temperature plays but a small part in their distribution. Food and enemies are of far more importance…'. It is probably a fair inference, however, that the climate was warm temperate and that habitats included both woodland and open country. It was warm enough for Hippopotamus amphibius during a relatively early stage of the Swalecliffe drifts when Palaeoloxodon antiquus was also living, and later there must have been sufficient vegetation to support Coelodonta antiquitatis. The presence of this woolly rhinoceros and of Mammuthus primigenius implies available woodland and scrub, but adaptability of the latter genus may preclude any assumption that the climate was entirely cold. As is well known, however, the mammoth was able to exist in Siberia, where its food was mainly from conifers; its abundance in both gravel and brickearth, for instance, around Oare and Faversham (Prestwich, 1892, p. 308) may mean that it flourished very strongly in a cold environment at the end of the Younger Head Gravel phase. Together with animals such as Hyaena spelaea, it certainly continued, however, to thrive in a later temperate climate, probably in an area largely beyond direct influence of the last glacial advances on the continent.

The mammalian remains confirm the general conclusions on the age of the brickearths arrived at from the molluscan evidence. Worsfold (1927, p. 224) has referred the drift at Swalecliffe to the 'third interglacial, fourth glacial and subsequent'. Palaeoloxodon antiquus, found only in the oldest bed, and at that locality, died out during the third and last (Ipswichian) interglacial period, while the strong predominance of Mammuthus primigenius and Coelodonta antiquitatis indicates a late Pleistocene age. The main fauna from Swalecliffe suggests either a late last-interglacial (Ipswichian) age or the equivalent of an interstadial phase during the last (Devensian) glaciation. Both the above forms, and Hyaena spelaea, became extinct only in this last glacial period. Other significant mammals from the brickearths on the coast are Megaceros giganteus, which occurs in late Pleistocene and Holocene deposits, Equus caballus, which is commonest in the late Pleistocene and Holocene, Rangifer tarandus, which ranges from late Pleistocene to early Holocene, and Bos longifrons, which is known with certainty only from Holocene deposits and may have been introduced by Neolithic man.

Human artifacts found in the brickearth or closely associ ated with it are numerous and come from localities on the Whitstable–Herne Bay–Reculver coast, where a good many have been washed out of brickearth on to the beaches, and from inland places such as Hoath and Sturry. They are mainly of the later Palaeolithic types but some are Mesolithic and Neolithic. Probably the earliest are Acheulian implements from Hoath, which seemingly long predated actual deposition of the brickearth series; some other Acheulian types, including very 'advanced' ones, are derived from the brickearth or associated gravels in the Reculver area. The latter also may date from an earlier period than the deposits themselves, which appear to have been largely contemporaneous with a culture of late Levalloisian man. At Swalecliffe (p.90) implement finds range from probable late Acheulian and Levalloisian to Upper Palaeolithic and Mesolithic ('Thames Valley Picks'), while at Hampton (p. 91) there is a Neolithic site. At Sturry (p.92) implements referred to Neolithic and Early Bronze ages have been found in association with the uppermost brickearth. SCAH

Details

In the Isle of Sheppey deposits of brickearth are of minor importance but their mode of occurrence is significant. They are all referable to the 3rd Stage of Head Brickearth and are found in the truncated valleys of the northern coast, where they occupy the slopes of the western sides.

A small patch occurs 320 m ENE of Bell Farm. Of two more patches relatively high on the valley-slope 0.5 km northward of Connetts, the western one showed in the cliff face [TQ 9874 7312] up to 3.7 m of brickearth with seams of small pebbles and chips of flint, whereas in the lower eastern one [TQ 9888 7308] the brickearth is laminated and has flints and pebbles at the base. Within 300 m of the stream (Hens Brook) farther east a tiny patch of drift [TQ 9925 7303] isolated from the main spread consists of 3 m of brickearth with a pebbly base up to 0.6 m thick. All these occurrences are the relics of more extensive drift which has been destroyed by coastal erosion, but the deposit on the west side of the truncated Hens Brook valley covers a larger area. A section [TQ 9942 7305] in the cliff showed:

A little to the east the brickearth also included flints at the base and chips of flint throughout.

The remains of further brickearth deposits are preserved in valleys and hollows cut by the cliffs near Warden Point. About 3 m of brickearth with a pebbly or flinty base occupies the west side of the (Barrows Brook) gully, 0.8 km NE of Mud Row. Just northwest and south-east of Warden Point two very small hollows at [TR 0188 7259] and [TR 0211 7218] contained respectively 1.8 m of laminated brickearth and 2.4 m of clayey brickearth with pebbles and flints in the bottom 0.6 m.

Wastage of the Sheppey cliffs has long been famous for the part it has played in exposing fossil remains from the London Clay. Occasionally drift deposits have also yielded fossils and it is probable that the tusk and bones of an elephant (mammoth) recorded from Leysdown 200 years ago by Jacob (1754, p. 626) may have come from head brickearth long since eroded away. SCAH, SB

The 3rd Stage brickearths of the mainland are broadly grouped in three areas; around Faversham, on the Blean (including its eastern margin and its abrupt curtailment at the northern coast) and in the valleys of the Great and Little Stour.

West of Faversham two tongues of loamy brickearth occupy broad dry valleys trending northward to Luddenham Marshes. The deposit is generally about 1.5 m thick and consists very largely of re-worked Thanet Beds material. Similar valleys southward of Faversham merge into gently undulating ground which carries more or less continuous spreads of brickearth, with or without underlying gravel.

The maximum thickness proved was at a well in the centre of the town, where about 6.7 m of clayey drift with a stony base rested on disturbed Thanet Beds; but the whole may be 'piped' into the Chalk, for an average thickness of about 3 m is more usual. A well [TR 0240 6173] 600 m ENE of St Mary's Church proved 2.7 m of brickearth resting on Thanet Beds. On the west side of Syndale Bottom brickearth containing sand, clay and green-coated flints washed down from Thanet Beds rises up the slope to about 40 m OD whereas on the east side of the stretch of head gravel in the valley bottom there is only a narrow belt of brickearth, bounded on the east by a steep valley side of bare Chalk. Neolithic flakes, in the Maison Dieu Museum at Ospringe, collected in 1926 from gravel pits in the Syndale valley presumably came from Brickearth, loam or soil at the top of the gravel or forming pockets in it. Short drift-filled tributary coombes from the west connect with the main valley at a number of points between the southern border of the map and the village of Oare. Near the last of these, at a point 900 m SW of the cross-roads in Oare, a small roadside pit [TR 0002 6217] showed 1.2 m of rich brown brickearth passing down into a paler more friable deposit, seen to a depth of 0.9 m, containing large brown abraded subangular flints and some green-coated flints at the base. Traced up the steep slope on the north-west the drift was seen to pass into a coarse stony loam or sandy wash with flints and pebbles derived from the adjoining hilltop. A section here was given by Hughes (in Whitaker, 1872, p. 80). Brickearth formerly covered much of the gravel at Oare but has been dug off, except for a very small and flinty patch 320 m SW of the cross-roads. Removal of brickearth hereabouts and elsewhere has sometimes added to the terrace-like appearance assumed by underlying head gravel. Between Oare and Uplees the deposit has been variably dug; because it takes on a rather coarse sandy nature here, reflecting the contribution of material from underlying and adjacent Woolwich Beds, it is a less satisfactory product and 1.5 m or more of the drift has been left undisturbed in some places. Brickearth has been dug off the London Clay near Uplees, 340 m SSE of which at [TR 0008 6417] was seen 1.2 to 1.8 m of sandy brickearth with flints at the top and bottom. The 1.5-m of partly dug brickearth bordering the marsh southward of Harty Ferry is variably sandy and clayey where it overlaps from London Clay on to Oldhaven Beds.

Faversham itself was formerly the centre of widespread activities in digging brickearth for brickmaking. The industry by the middle of the present century became much restricted, but in and around the town the remains of very numerous old workings are much in evidence. On the map, the pattern of brickearth in relation to gravel and underlying Thanet Beds and Upper Chalk in fact is largely due to such excavations as well as to natural causes of distribution. The brickearth westward of Ospringe is over 3 m thick on the side of the hill; it crosses a valley but is continuous with the drift at the brickworks beyond the Watling Street and the railway. In the railway cutting north of Judd's Hill Whitaker (in MS) noted around 2.3 m of brown brickearth resting on gravel, but a little to the north-east at [TQ 9973 6138] 3.4 m of brickearth, with scarce flints, a few chalk pellets, some thin lines of white flint chips about 1.2 m down and a loamy base was proved in 1938 to rest on Thanet Beds. To the east and north-east, however, the brickearth passes on to gravel and thins out, or has been dug off. At one point [TQ 9977 6174] the brickearth was seen to be interrupted by a sharp ridge of underlying gravel, probably the result of frost-heaving; at another [TQ 9988 6174] a full thickness of 3.7 m was seen, the top 1.2 m being dark and compact and the rest paler and slightly laminated. Workings in 1951 proved that the brickearth in the valley on the north-west was generally much thinner than on the hill and slopes around and above 15 m OD. Brickearth runs out sharply against Davington Hill on the south-east. Impure brickearth extending beyond the road to Oare towards Ham Marshes generally amounts to 1.8 m or more on gravel. Hughes (in MS) mentioned shallow sections in this tract 'in a very irregular loam with lines of gravel on an irregular gravel with lines of loam'. He emphasised that 'the gravel is not waterworn though the whole deposit looks rather as if it had been sorted by water action'. Brickearth associated with a chain of small mounds in the Alluvium 0.4 km NW of the Ham is probably artificially disturbed. SCAH

Up to 3 m of brickearth was exposed in the Oare quarry [TR 014 625] in 1976 (see p. 82). RAE

On the east side of the Ospringe valley two small patches of brickearth occur with a terrace-form on the Chalk hillside. They were exposed at about 25 and 35 m OD at the top of the north and east faces of the old chalk pit [TR 004 603] 320 m E of Ospringe Church. The drift is mainly a fine-grained brickearth, with very few flints, which thins out laterally into a rubbly loamy soil. In the south-east corner of the pit, however, 1.5 m of brickearth with impersistent thin seams of small flint chips and of chalk pellets rested on a strong bed of unworn chalk flints, some green-coated, capping 0.6 to 0.9 m of chalky rubble with large flints and intercalations of brickearth. The base of the drift follows in detail the slight irregularities of the brickearth above the stony bed, thereby indicating that the deposit was disturbed as a whole at a late date, probably either by solution or frost action, or a combination of both.

Of the brickearths which rest on Chalk or Thanet Beds on the south side of Faversham the deposit some 0.3 km SW of the station afforded an interesting section when dug many years ago in a brickfield [TR 015 607] at a site known as King's Field (Figure 9). Hughes in his MS account drew attention to the irregular base of the brickearth, which here and elsewhere carried a bed of large 'greywethers' or sarsens and a few subangular flints and pebbles. The brickearth thickened into a 4.6-m hollow on the north and there became slightly laminated, but on the south it was not more than 1.2 m thick and lay evenly on the Thanet Beds, without showing signs of disturbance by a solution pipe of Thanet Beds in Chalk which was exposed below it.

Other sections seen by Hughes were at the former Faversham Quay Brickfields [about 024 619] just north-east of the town, where the lowermost Thanet Beds were also worked for brickmaking (Whitaker, 1872, p. 85). Up to about 3.7 m of drift consisted of brickearth with variable colour and clay content and, at the base, a 'line of flints, bits of greywether sandstone, broken pebbles, etc.', 0.15 m thick. The junction with the Thanet Beds was sometimes very irregular, the resorted top of the latter 'appearing to be undermined and washed over' the gravelly base of the brickearth in places, according to Hughes' MS notes. This general locality is possibly the site from which Trimmer (1851, p. 36) recorded non-marine shells from a deposit 'in the neighbourhood of Faversham' and 'extending below the level of high water'. The fauna was also discussed by Kennard and Woodward (1901, p.224) and the bulk of Trimmer's specimens, originally presented to the Geological Society of London, are now in the Geological Survey collections (Geol. Soc. Coll. 327–337) at the Institute of Geological Sciences. The following list is compiled from Kennard and Woodward's published account, from specimens labelled by the late A. S. Kennard and from notes by S. P. Woodward which he saw.

• Land mollusca: Candidula crayfordensis, Cernuella virgata, Monacha cartusiana, Succinea putris, Theba cantiana, Trochulus hispidus
• Land or fresh-water: Lymnaea truncatula
• Fresh-water mollusca: Bithynia tentaculata, Lymnaea palustris, L. peregra, L. lagotis, Planorbis carinatus, P. leucostoma, P. spirorbis, Pisidium amnicum, Sphaerium rivicola, S. corneum, Unio pictorum, Valvata piscinalis

Some of these fresh-water forms probably required freshly flowing water but others could thrive in shallow lakes or marshes. The land mollusca indicate habitats either damp or open and dry. Candidula crayfordensis did not survive the Pleistocene but other species are common to that period and the Holocene. Theba cantiana and Monacha cartusiana are Holocene forms in England, however. It is evident that a variety of conditions obtained from late Pleistocene to Recent. Possibly the younger drift represents an early freshwater alluvial deposit, made up of re-worked brickearth during the initial phases of valley drowning which brought the Faversham creeks into being; the absence of estuarine or marine forms strongly suggests circumstances unconnected with the modern Alluvium.

More recently a temporary exposure [TR 0167 6129] about 275 m SSW of St Mary's Church showed about 3.7 m of brickearth, somewhat sandy at the base, with fragments of shells and a bed of small sandy calcareous concretions resting on Chalk or chalky rubble, the junction having a slight northerly inclination. Old diggings around [TR 022 609] within 0.8 km eastwards of the station exposed 0.9 to 2.4 m of pale brickearth either passing down insensibly into Thanet Beds or, on the south, resting with an uneven junction on the Upper Chalk and including a basal bed of green-coated flints, Chalk flints, subangular flints and a few Tertiary pebbles. Whitaker (1872, p. 85) saw brickearth in the railway cuttings eastward of Faversham. In the one [TR 025 605] 1 km ESE of the station about 1.2 to 1.8 m of brickearth was seen in 1939, but the cutting [TR 0315 6132] about 1.6 km ENE of the station exposed some 3 m of brown brickearth with a paler and more friable base.

Evans (1897, p. 611) described fine examples of ovate flint implements collected at Ospringe and 'from the brickearth at Faversham'.

Westward of Goodnestone brickearth covers a somewhat uneven surface of Chalk and Thanet Beds but to the east it is sharply bounded by steeply rising ground. A well [TR 0446 6166] at Goodnestone Court proved 3.7 m of loam and sand, probably drift, on Thanet Beds. Another stretch bounds the Alluvium west of Waystreet Farm on the western side of the valley, reaching to 15 m OD in a dry tributary coombe near Fairbrook Farm and northwards where it crosses an uneven topography of Woolwich and Oldhaven Beds near Graveney and Broom Street. An isolated patch north of Sandbanks is a rather sandy brickearth. An old pit [TR 0530 6290] 610 m N of Graveney church showed 1.8 m of clayey brickearth on London Clay. Brickearth was dug to 1.8 m just east of Graveney, but on the side of the hill between there and Culmers the brickearth tends to be gravelly and there are also indications of gravel patches beneath it.

Around Hernhill there are six isolated patches of Head Brickearth. About 0.5 km WSW brickearth is strikingly restricted to the southern side of a small tributary valley and is tongued up-slope to about 20 m OD; 0.4 km SE a somewhat clayey brickearth occupies low ground about the junction of Woolwich and Thanet Beds and evidently contains material derived from them; a very small patch of sandy brickearth lies at the head of the valley 1 km ENE; a spread of brickearth 0.5 km NE of Fostall is sharply limited at its eastern margin, where it tends to be very clayey; at Fostall flinty brickearth 1.8 m or more thick is disposed unevenly on the south-west side of a short valley, where it reaches 30 m OD on the south and descends to Alluvium level on the north; lastly, capping the hill just south of this spread is a very small patch of stony brickearth with gravel beds and pockets, seen to a depth of 1.5 m at the top of the adjacent Fostall sand-pit (p. 33).

Special interest attaches to the flat tract of very clayey brickearth that extends northward of Dargate Common. Topographically it resembles an alluvial flat with a clearly defined limit all along its north-eastern and eastern side. The material is mostly a stiff ochreous and grey-weathering clay, very similar to undisturbed London Clay, from which on the south it becomes litho-logically inseparable in the field when traced laterally. Temporary drainage trenches have shown the drift to be up to 1.8 m thick, e.g. where it rests on Woolwich Beds about 650 m ENE of Dargate House, but where it rests on London Clay it passes downwards insensibly into the weathered top of that formation. Surrounding features suggest that this drift resulted from the silting up of a muddy lake, filled with downwash from the London Clay and impounded behind a low ridge north-east of Dargate House. At a later period of denudation this ridge was cut through by an ill-defined channel which now exhibits a gentle south-western side and a steeper north-eastern side.

No brickearth was mapped at Seasalter, but Whitaker (in MS) noted that tusks of mammoth in the Canterbury Museum were obtained from the cliff there. These probably came from a pocket of drift in the London Clay, or from a small patch subsequently removed by coastal erosion. A hollow crossed by the railway southward of Tankerton carries drift which Whitaker described as a clay with, at the base, pieces of flint in a thin layer which thickens eastward to become a gravel bed 0.3 m thick resting on London Clay.

Drift proved to be continuous in the long irregular valley that extends from near Honey Hill northward to Swalecliffe. It is not confined to the valley-bottom but tends to pass laterally up-slope into undisturbed London Clay, though at a few points, e.g. near South Street, it is sharply bounded by a narrow gorge. In the region of Bogshole Farm there are broad flats of clayey brickearth and at a number of points the valley receives tributary tongues of drift, e.g. west of Chestfield village; but beyond the railway the drift expands to form a spread confined to the sloping western side of the valley between Swalecliffe and Tankerton. It was formerly worked in a brickfield [TR 1327 6729] 300 m W of Swalecliffe church. The present stream is incised into the drift. Its banks afforded numerous small sections and showed that within this valley an appreciable amount of drift first occurs near the main road through Honey Hill. Most of the sections showed 0.6 to 1.5 m of clayey brickearth or stiff brown clay. A few flints or up to 0.6 m of very coarse unworn gravel were noted at the base.

Details of the drift formerly to be seen in the low cliff [from about 130 674] eastward of Tankerton are shown in the generalised section (Figure 10). The beds show a great variety in gravel content, bedding and disturbance, but much of the clayey brickearth which predominates is homogeneous in character. The section has been drawn to illustrate these features diagrammatically and the junctions of the drift lithologies are not necessarily as sharp as there shown. The configuration of the deposits, principally on an easterly-facing slope of London Clay, is shown by the diagram; allowance must be made, however, for the vertical exaggeration. A shell-bed (see below) has been exposed periodically at a low level in the channel of brickearth into which the deposits grade on the east. The mammalian remains found by several collectors were derived not only from horizons in the main body of the deposit but also from an older bed high on the west which corresponds approximately with the basal flinty clay at the point [TR 1302 6738] nearest to Tankerton, near Priest and Sow Corner.

The brickearth contains white subangular flints and less common brown-stained ones, Tertiary pebbles, locally a few small white calcareous nodules and at some levels manganese-stained seams of gravelly sand; a few pieces of derived ironstone were noted on the east and fossil wood has been found. Septarian nodules derived from the London Clay also occur locally at the base. Where the clayey drift is columnar-jointed and dicey, notably at the top, it appears very similar to London Clay, as Whitaker observed (in MS) while inclining to refer the deposit to 'rainwash'; but streaky sandy laminae and stony beds or lenticles are well developed in the lower part. At its maximum the drift is about 6 m thick.

These Swalecliffe deposits have been investigated in considerable detail since they were referred to by Richardson (1834, p. 79; 1841, p. 211) who collected mammalian bones there. Prestwich (1861, p.365, fig. 2) noted drift, with bones, land shells and implements, resting on an easterly slope; since that time marine denudation appears to have reduced the highest-level drift occurrence appreciably and it is uncertain whether the high-level gravel later mentioned by Prestwich (1865, p.254) should be referred to a capping of Intermediate Head Gravel now eroded away. Apart from a brief mention by Evans (1897, p. 617) the next published account was by Kennard and Woodward (1901, p. 240) on mollusca from the brickearth. Dewey (1925, p. 283; 1926, p. 1432; 1955, p.165) has drawn attention to the varied nature of the Swalecliffe deposits and of the faunas and implements found in situ or on the adjoining foreshore. He referred to the work of Worsfold (1926, p.326; 1927, p.224), who published the most extensive accounts of the deposits and their faunas. Conclusions on the dating and climatic conditions discussed on p.87 are largely the result of Worsfold's collecting of shells, mammalian remains and flint implements, some of which are now in the Maidstone Museum. Bones of mammals obtained by local collectors are also included in the material in the museums at Herne Bay and Canterbury and some have been acquired for the Geological Survey collections. Further examples of non-marine mollusca are listed by Burchell (1954, p. 259), who was able to trace the distribution of the marsh-loving Succinea oblonga across the eastern deep channel of brickearth and to demonstrate a lateral transition from dry to moist conditions at the fossiliferous horizon, which is limited in occurrence to a position low down within the drift. Further collecting by Mr J. N. Carreck and Dr M. P. Kerney between 1953–55 has added much to the understanding of the Swalecliffe drifts and their faunas. The following details are compiled from the former's notes.

a)      Mammalian remains from about 1.1 m of brickearth and gravel in the cliffs from the eastern end of the promenade at Priest and Sow Corner, Tankerton, to a point about 330 m to the east; fossils concentrated in the basal 0.3 m of bluish grey argillaceous gravel but also present at levels above: Bos or Bison, Cervus elaphus, 'Elephas' sp., Hippopotamus amphibius, 'Rhinoceras' sp.

b)      Mammalian remains found lying scattered on the foreshore in front of the above section of cliff; matrix within these specimens closely comparable with the drifts lying on the London Clay. List as above except that Cervus elaphus was not found but Megaceros giganteus was obtained.

c)      Non-marine mollusca from the shell bed (see also Burchell, 1954, p.259, and previous references) in the low cliff by Swalecliffe sewage works [TR 131 674]; the bed is a light grey argillaceous loam about 28 cm thick, with an indistinct central band of ochreous staining, some small nodules of calcareous 'race' and scattered subangular flints. All are land species identified by Dr M. P. Kerney. Agriolimax sp.[small form], Arion sp.,Columella columella, Pupilla muscorum, Succinea oblonga (S. oblonga vera, non S. arenaria). Over 90 per cent of the mollusca are referable to S. oblonga and P. muscorum. Whereas the deposits represented by (a), (b) and (c) are late Pleistocene the following are from the lower part of a Holocene brickearth, overlying the Pleistocene deposits, in the cliff [TR 1298 6738] about 265 m E of Priest and Sow Corner. The drift consists of 0.75 m of brickearth with flint pebbles, evidently of recent beach origin, resting on an older grey argillaceous brickearth, 1.6 m thick, mottled with iron oxide, containing scattered subangular flints and showing 0.2 m dark horizontal layers (probably carbonaceous] at intervals of 0.3 to 0.45 m. Bos sp., Equus caballus, Mytilus edulis, Ostrea edulis, Ovis or Capra.

Because 'pot-boiler' flints, fragments of charcoal and shards of early pottery were found in association with these latter remains it is concluded that the deposit contains midden debris from a nearby human settlement. Regional evidence suggests, however, that the drift material is pre-existing brickearth disturbed and re-arranged by human agency. Mr. Carreck notes (personal communication) that the cliff sections were entirely hidden under concrete by 1959.

Underneath a shell bed, approximately equivalent to the bed described under (c), Worsfold (1926, p. 333) obtained worked flints (Levalloisian) and teeth of Coelodonta antiquitatis from a blue-grey brickearth about 3.7 m below ground level on the low cliff. Worsfold's records of mammalia from a 'bone bed' of early date high on the west, and corresponding with the deposit and fauna noted under (a), include additionally Palaeoloxodon antiquus and Bos primigenius. He lists from stratigraphically younger deposits at a low easterly horizon a fauna which he considered to indicate colder conditions: Coelodonta antiquitatis, Equus caballus, Hyaena spelaea, Mammuthus primigenius.

Loams at a higher level on the east yielded Rangifer tarandus and Canis, while Bos longifrons was obtained from a still more recent deposit of gravel and brickearth in the western part. The latest worked flints, of Mesolithic type, were found in a covering of 0.45 to 1.4 m of disturbed clayey 'rainwash', with carbonised material and pot-boilers, similar to the deposit described under (d). Worsfold was able to show that the many 'Thames Valley Picks' dredged up from the adjoining Kentish Flats can be related to this deposit in a manner similar to the relation of submerged mammalian remains to eroded older brickearth or of Roman objects, for instance, to subsequently foundered coastal land. Since Worsfold's full investigations were made, a jaw of Rhinoceros hemitoechus has been found at Swalecliffe. Dewey (1925, p.283; 1926, p. 1432) mentions bear (Ursus sp.) and pig.

The following list of non-marine mollusca, additional to the species noted above, is compiled from early determinations in the published work of Kennard and Woodward, Worsfold and Burchell cited above, and from MS notes by the late A. S. Kennard in possession of the British Museum (Natural History). Specimens of Pupilla muscorum, Succinea oblonga, Arion sp.and Limax sp.are also in the Geological Survey collections (Za 4931–4940). Probably all came from approximately the same bed as described above, and all are characteristic of dry land or marsh. Apart from the slug Arion ater they are not abundant, being greatly dominated by P. muscorum and S. oblonga. Agriolimax laevis, Arion ater, Columella edentula, Lymnaea truncatula, Succinea pfeifferi, S. arenaria, Trochulus hispidus, Zonitoides nitidus.

Worsfold obtained the following from midden material considered to be of an age similar to the 'shell mounds' of Denmark: Cardium edule, Littorina littorea, Mytilus edulis, Ostrea edulis.

A small valley extending from West End to the cliff at Hampton carries clayey brickearth, about 1.5 m thick on the south and up to about 4 m on the north. Again the deposit extends up the valley side on the west, whereas, for the greater part, it is bounded by London Clay slopes on the east. The cliff exposed on the west [TR 1547 6780] a bed of clayey sandy brickearth, with calcareous nodules and pockets of small flints, which is noted to overlie the London Clay and gradually thickens down the slope eastward to form 2.4 to 3.0 m of columnar stiff clayey brickearth containing many lines of white calcareous 'race' nodules and a few, mainly small, subangular flints and pebbles, concentrated at the base. The drift lies more evenly and is less variable in character than the Swalecliffe deposits. The top half is darker in colour and the beds show a gentle easterly inclination corresponding with the fall of the underlying London Clay. The basal bed locally tends to form two 0.15 m gravelly bands about 0.45 m apart and may be irregularly contorted. When seen by Whitaker (MS notes) the low cliff at that time revealed three distinct beds:

Evans (1897, p. 617) noted that the deposits contained land and marsh shells. Sections in the area have been studied by Burchell (1924, p. 208), who obtained evidence of Neolithic and Medieval occupation sites in the disturbed upper layers of the drift. Shells from a midden of the latter period may explain the presence of Mytilus edulis referred by Kennard and Woodward (1901, p.241) to 'the scanty remains of a marine deposit'. In MS notes Kennard later recorded that 'in 1902 the low cliffs at Hampton were cut back by the sea and in the small valley exposed the site of a Roman oyster pond with abundant oysters under about 3 feet [1 m] of wash'. Besides fragments of Samian pottery there were the brackish-water shells Hydrobia ventrosa and Peringia ulvae. It is significant that one metre of drift had accumulated since the Roman occupation. Bones of Bos longifrons from Hampton are in the Herne Bay Museum collection. The brickearth was formerly worked for tile-making and bricks.

At Bullockstone another narrow valley has a tongue of brickearth which expands appreciably northwards into a broad spread around Love Street, where a clayey or loamy deposit some 0.6 to 0.9 m thick bears little relationship to the gently undulating form of the ground. There are also three isolated patches just east of the main area and another in the centre of the bare clay tract at Love Street. On the north-west a rich brown brickearth connects with the Hampton valley brickearth, from which it is separated on the west by an erosional feature of London Clay.

The railway cutting [TR 167 674] westward of Herne Bay Station showed 1.8 m of brickearth on London Clay, while at the Gas Works a well proved 3 m of the drift. Most of the western part of the town is built on a continuous spread which was formerly dug in a number of places. In 1863 Whitaker (in MS) noted diggings to 2.1 m in a rather stiff brown brickearth, at a brickfield about 0.8 km westward of the Pier. As the brickearth rises to over 15 m OD against the hill on the west its local basal gravel crops out on the London Clay. Whitaker refers to bones of mammoth and ox from Herne Bay in the museum at Canterbury, while Dr A. Bowes' list of fossils under that heading in the Herne Bay Museum includes Cervus elaphus (an antler pick) and Bos longifrons from the Iron Age site on rising ground near the edge of the brickearth spread in the east part of the town. Other bones are recorded from the foreshore, of which Megaceros giganteus and Bos primigenius may have been washed out of the local brickearth.

At about 15 m OD on the west side of Bishopstone Glen [TR 2067 6872] about 3.7 m of brickearth (see (Plate 1)), columnar in the upper half but showing lamination below, rest with a thin gravelly base upon a surface of Tertiary beds sloping slightly eastwards. As the drift has been cut off at a high level by the development of the deep gully which forms the Glen it cannot be very recent in origin. Two further patches of drift referred to Head Brickearth of the 3rd Stage occur just west of Reculver, in a hollow at about 11 m OD and on an easterly slope from about 18 to 5 m OD. At a point [TR 2202 6911] in the centre of the hollow, about 0.8 km WSW of the ruined church, about 2.4 m of brickearth was noted. The drift 0.4 km E of the last [TR 2238 6923] showed a basal line of flints and pebbles resting on Thanet Beds. The following land molluscs, recorded from Reculver ('ex A. G. Davis and R. Tripp') by the late A. S. Kennard, in his notebooks in the British Museum (Natural History), presumably came from one of these patches of drift:

All along the sea-shore between Herne Bay and Reculver flint implements have often been found, generally water-worn according to the amount of wave action to which they have been subjected. There are collections in the Canterbury Museum and others, including examples obtained by Dr A. Bowes, in the Herne Bay Museum. They are derived from deposits of several ages and because the general direction of long-shore drift is from east to west, worked flints from the 3rd Stage brickearths at Reculver, for instance, may occur at the same localities as implements fallen directly from earlier deposits such as the Intermediate Head Gravels. In addition to those examples known or believed to have come from the older drifts (see, e.g. p. 73) many others, including types referable to late Acheulian, have been occasionally found. In the Geological Survey collections pointed hand-axes (M.I. 25559, 25560, 25561) and an ovate form (M.I. 1968) are thus classified. In the British Museum's Stone Age guide (1926, p.36, fig. 24) is an illustration of a triangular implement and mention of a deeply ochreous-stained Levalloisian flake. An illustrated account given by Evans (1897, pp. 613–617, 642) is the most comprehensive available and includes references to many earlier records. Pointed, triangular and curved ovate artifacts thought to be of relatively advanced types were probably fashioned later than the deposition of the 2nd Stage but became incorporated in more recent drifts even if they predated their basal gravel deposits. Possibly the brickearth at Reculver or some other patches removed by coastal erosion may have become the source of these implements.

Southward of Reculver a patch of brickearth at about 15 m OD on the side of the hill is crossed by the Isle of Thanet coastal road about 0.8 km ENE of Hawthorn Corner; a spread at a lower level near Oar Farm extends as a spur into the marsh. Whitaker (MS notes) recorded about 1 m of brown clayey brickearth in the railway cutting here [TR 231 683].

There is a small patch of brickearth 0.8 km NE of Herne Church and a further more pebbly outcrop is crossed by the road northwards from Ford. A much stronger development, however, is shown on the south side of the valley. The spread over 0.8 km W of Millbank may be a comparatively old deposit, for though it is related to a narrow tributary valley it ceases to be represented in the lower reaches of the valley, after being joined by a mass of drift, 1.5 m or more thick, which mantles a broad depression and hill-slope on the north. The same may apply to a tiny patch 100 m W of the road at Millbank and certainly governs the interpretation of the brickearth north-westward of Hoath, which abuts against Intermediate Head Gravels and also appears to have been subject to later erosion. Gravel formerly worked [TR 202 643] about 100 m NW of Hoath Church is partly overlain or pocketed with brickearth. Specimens of an ochreous and slightly rolled Acheulian ovate palaeolith and an unrolled small triangular implement described as late Acheulian were found by Bowes (1928, p. 517) 'at a depth of 3 ft. [0.9 m] in the gravel'. It is clear that these relate to drift much younger than the main body of gravel but older than most of the 3rd Stage deposits. The ovate tool probably lay weathering on an old land surface for a long period before it became incorporated in gravel and brickearth deposited at the beginning of the 3rd Head Stage.

The broad spread of brickearth which extends north and east to Wear Farm and beyond Chislet, however, is younger, for it mantles a gently undulating mature topography of Tertiary beds and Chalk which are overlain by dissected deposits of the Second Terrace at Wear Farm (p. 77) as well as by local patches of Younger Head Gravel (p. 82). Sections in three old pits near Wear Farm on the west and south showed up to about 2.5 m of loam and brickearth with pockets of flints and pebbles or a gravelly base; but formerly the drift was much more clearly exposed and was seen in the pit [TR 224 650] 275 m SSE of the farm to lie unevenly on older drift, Thanet Beds or Chalk (Prestwich, 1855, p.111; Dowker, 1864, p.341; Brown, in MS; Whitaker, in MS). Judging from these descriptions and from evidence at the other two pits there appears to be a general north-easterly sloping plane of discontinuity at the base of the brickearth. The pit 400 m W of the farm is not mentioned in published accounts, but in the one [TR 222 651] on the west side of the road 180 m SSW of Wear Farm, Prestwich noted that the 0.9 to 2.4 m bed of rubbly gravelly brickearth he saw in the easterly pit was 'much more developed and predominant', while a description by Whitaker (1872, p. 89) implies that the drift thins southwards. Evans (1897, p. 621) refers to elephant remains found in this pit.

Brickearth which covers the spur northward of Grove Ferry may have formerly extended to make contact with the gravel near Up-street Farm, but drift was extensively dug out hereabouts over 100 years ago, when Brown (in MS, see p. 77) recorded a section of gravels capped by younger drift.

Some of the most characteristic clayey brickearths of the Blean cover the London Clay in the valley of the Sarre Penn and its tributary valleys near Tyler Hill and at Rushbourne. Except in some very narrow branches the drift does not lie flat in the bottoms of the valleys but clings to the sides, predominantly on the south and west. Sections are practically confined to the banks of the streams, which are sharply incised into the drift to a depth of about 2 m without reaching solid. The brickearth is rarely stony but becomes progressively less friable and more clayey downwards. An amount of gravel in the stream beds was probably washed out of local gravelly beds at the base of the brickearth, however, which are occasionally exposed. In a few places the brickearth has been dug on a small scale. About 0.4 km westwards of Brittoncourt Farm the brickearth, though restricted on the north side of the valley, on the southwestern slope sweeps up over 60 m to join with similar brickearth of the 1st Stage on the plateau near Blean. There appeared to be no physical line of demarcation between the deposits, and the younger head was probably derived from the older drift largely by soil creep and sludging into the valley. Brickearth about 0.8 km NE of Brittoncourt Farm occupies a dry valley sloping eastward to the stream. South-east of Calcott brickearth broadens southward to mantle the London Clay slopes up to 30 m OD. A well [TR 1739 6226] 0.8 km E of Vale Farm indicated about 3.7 m of clayey brickearth with gravel in the basal 0.3 m. Brickearth about 0.8 km WSW of Tile Lodge contains a few gravel lenticles. Where the brickearth of the Rushbourne valley first occurs, near Hicks Forstal, it also spreads from the south-western valley side. At 0.4 km WSW of Rushbourne about 1 m of the drift, in the valley bottom, was formerly dug off the London Clay at an old brickworks [TR 1932 6347]. South-east of Rushbourne brickearth again rests on ground sloping to the east, while at Chislet Park it covers a broad area of hill-slopes and valleys on the south side of the Sarre Penn stream.

Along the northern side of the Great Stour valley Head Brickearth of the 3rd Stage occurs as a continuous spread of drift which to a large extent masks the Tertiary beds and River Gravels (see (Figure 8)); except for two small patches of Second Terrace gravel these deposits would, in fact, hardly have shown at the surface if the brickearth had not been dug off. While the main bulk of the deposit covers uneven slopes ranging from about 15 m OD down. to Alluvium level and below, the brickearth additionally extends to over 30 m OD northward up numerous short valleys which cut the Tertiary escarpment and it also mantles the scarp slope on the edge of the plateau northward of Sturry. Its thickness is commonly of the order of 3 m and at the pit [TR 1746 6080] on the west side of the Herne Bay road north of Sturry (see p.74) 4.3 m were proved; 1 km NE of Sturry [TR 1856 6129] 6 m occurs. Gravel may or may not be present at the base and the drift tends to be very clayey where it rests on London Clay but rather loamy where it is in contact with sands or gravels. The clayey type is typically hard and columnar-jointed and frequently contains white angular flints, scattered or in impersistent bands.

In the several old Sturry gravel pits east of the Herne Bay road the 'callow', or overburden of loam and variably stony brickearth was on an average about 1.5 m thick. Small gravelly pockets were seen but very little basal head gravel was exposed in 1946. About 140 m E of the road old workings in the northern part showed at one spot [TR 1768 6086] a 3-m channel of brickearth with a few white flints at the top, and at another about 0.6 m of brickearth with scattered flints and lumps of ironstone, resting on 1.5 m of rich orange-brown brickearth on clayey gravel. A narrow north–south valley, 225 m E of the road, separates two spreads of gravel and coincides with another narrow channel of brickearth which connects with the loams on lower ground to the south. The uneven way in which brickearths and loams of several kinds rest upon the bedded gravels and cut across them on the slope of the hill at Sturry was illustrated by Breuil (1934, figs. 23, 24) in detail which is rarely observed and not constant beyond very limited areas. Implements found in association with the brickearths at Sturry and nearer Canterbury have indicated cultures from late Acheulian and Levalloisian to Neolithic and early Bronze Ages (Dewey, 1925, p. 280; 1926, p. 1432; 1955, p. 166; Dewey and Smith, 1925, p. 124); but many of these, especially the older ones, are probably derived and some of the younger appear to have been either surface finds or associated with rainwash. Some much-rolled flakes from 'trail' at the top of 'Homersham's Pit', Sturry, are in the Geological Survey collections (M.I. 25553, 25554).

Brickearth cut in the disused workings [TR 185 613] for gravel and sand nearly 1 km NE of Sturry Station, in Hoades Wood, showed again its manner of disposition in steep narrow valleys in the Tertiary escarpment; southward it overlaps across Third Terrace deposits to connect with a broad spread on gently undulating lower ground. The Alluvium of Westbere Marshes overlies its featheredge (Figure 8). The great pit in Hoades Wood exposed rich brown brickearth which varied from about 1.8 m on the slopes to about 6 m in a narrow valley bordering the road to Hoades Court. Within 0.6 m of the base the drift was generally gravelly and locally very clayey or with dislodged masses of Tertiary beds incorporated in it, but higher up gravelly seams may also occur. Dewey and Smith (1925, p. 133) saw an almost stoneless brickearth, yellowish-buff and with ochreous seams or laminae and occasional clumps of pebbles.

Near Westbere numerous short coombe-like valleys carry brickearth, and the main spread traversed by the railway is a heavy rich brown deposit, with a more friable top occasionally, seen to 2.4 m in the cuttings. It was formerly dug [TR 2012 6140] 0.8 km ENE of Westbere Church. A very narrow belt of brickearth with a few flints and pebbles borders the marsh 2 km farther east-north-east.

The spurs of Tertiary beds between the valleys of the Great and Little Stour are closely enveloped by Head Brickearth of the 3rd Stage, which also overlies Second Terrace gravels or has Younger Head Gravel associated with its base in some places. Brickearth with gravelly seams is 1.5 m thick [TR 2196 6086] 100 m NW of Stodmarsh Church and a similar thickness of brickearth with a gravelly base was proved in the lane [TR 2224 0043] 250 m SE of the church The deposit extends from Alluvium level to over 15 m OD on the central hills. Over a large tract south-west of Grove it is a rich brown loam with a virtual absence of stones.

On the east side of the Little Stour brickearth is so extensively developed that it almost completely masks both older drifts and the Tertiary beds. The only areas relatively free are west-facing slopes at Preston and at Elmstone, 1.2 km ESE. A very narrow belt of brickearth bordering the Alluvium 1.2 km SW of Preston is abruptly joined by the main mass near Preston Court, where about 1 m of brown clayey deposit, commonly gravelly at the base was seen by Whitaker (MS notes) to overlap a little way on to gravel. The disused pits 0.4 km NW of Preston Street showed high on the east [TR 2478 6132] up to 1.5 m of a very stiff clayey brickearth with white battered flints, but the drift was only fully exposed in the later workings [TR 2512 6173] 550 m northward of the inn. Details of this deposit, which is up to 4.6 m thick, very clayey and contains calcareous nodules, are given with the description of Second Terrace gravels at this location (p. 77). Where the brickearth laps over rising ground it tends to be thinner, being, for instance, about 1.5 m at Dean Farm [TR 2552 6238] and somewhat less at about the 15 m OD level east of Preston. It is mostly very heavy in texture but tends to be influenced by the nature of subjacent solid beds, becoming a little sandy beyond the London Clay boundary and showing the presence of underlying Oldhaven Beds in the local abundance of pebbles; subangular flints are generally few. Brickearth was formerly worked [TR 263 633] 0.8 km NE of West Stourmouth, where it thickens from the hill northward to the alluvial tract. A similar deposit appears on the north of the latter at the border of Sarre Marshes.

In the area between Potten Street and Sarre, brickearths are present in two distinct topographical situations. The older deposit forms a capping to the plateau-area north and east of St Nicholas Court and around Potten Street, up to 1.5 m thick. The younger deposit occurs within the dry-valleys, but with a greater lateral extent than typical dry valley deposits, and may extend on to the lower parts of the intervening spurs. In the latter situation pockets of pale yellowish brown loam with angular flints overlie chalky rubble with a markedly irregular cryoturbated contact, as noted near Chambers Wall [TR 2557 6762]. SCAH

Alluvium

Flandrian

Wide tracts of alluvium form the marshes on the south side of Sheppey and between Faversham and The Swale; a broad belt also extends from the valleys of the Great and Little Stour along the west side of the Isle of Thanet to reach the sea east of Reculver; narrow tongues may occupy small valleys and their truncated remnants at the coast.

While most of the alluvial deposits are Recent, and indeed continue to form at the present day, it is possible that some of the deeper layers may date from the initiation of marine incursion during the Pleistocene. Stages of such incursion in the Thames Estuary have been deduced in some detail by D'Olier (1972, pp. 125–129), but these refer strictly to a period in the early Holocene from about 9600 to 8000 years B.P. At its commencement the shoreline was far to the north-east of the Isle of Thanet and inshore there was a spread of flood-plain alluvium and fluvioglacial drift. By the end of the period marine inlets had apparently reached as far south as the present general north-east Kent coastline but there remained an uneroded spur of land extending east-north-east from Sheppey. It is considered that the present sea-level was achieved approximately around 5000 B.P., 'since when it has risen only slowly and slightly' (D'Olier, 1972, p. 123); after the close of the Ipswichian around 70 000 B.P., however, the sea level had eventually fallen to −100 m OD and more, and it varied with the Devensian climate oscillations.

From the distribution of Second Terrace deposits and their fauna (at Grove Ferry and Wear Farm) in the Great Stour area there are indications of an estuary running between Chislet and the Isle of Thanet as far back as the Ipswichian (pp. 77–78). This would have carried alluvium in continuity with the Thames Estuary at a date earlier than D'Olier was able to record; of this and possibly even earlier alluvial muds corresponding to preceding interglacials little, other than associated local coarse gravel, is likely to have survived the Flandrian erosional and re-depositional processes that have so strongly modified any proto-Thames estuary.

The Alluvium shown on the map is for practical purposes a Flandrian deposit. Locally it is seen to be overlain by younger Hillwash Head. On the other hand the major part of the silting up of the Wantsum, between the Isle of Thanet and the land southward of Reculver, was only accomplished within historic time and was still proceeding during the Roman occupation.

Without detailed local sections it is not possible to separate alluvium of fresh-water and marine origin; but it is noteworthy that as a result of the drowning of the Stour valley, known also from historic evidence, the marine shells Cardiurn and Scrobicularia occur as far from the present coastline as Stourmouth (p. 94). There are indications of buried peaty 'forest beds' in Sheppey and at Whitstable and molluscan faunas from a number of other localities indicate land and fresh water, marshy and brackish or marine conditions. A few vertebrate remains have been recorded.

Within the area of the Faversham (273) Sheet the greatest thickness proved was 10.4 m, mainly of black mud, in a borehole at the old Oare Powder Works in the marshes at Uplees. Another boring here proved 10.1 m of river mud, etc., resting on 2.4 m of black ballast and shells which probably represent disturbed Oldhaven Beds, perhaps redeposited by marine agencies during the incursion of the sea which brought into existence the Swale Estuary. The alluvium is also thick in the eastern part of the Stour valley, beyond the sheet boundary, and 6 to 9 m may therefore be present in the deepest parts of the channels about Stourmouth. Over 7 m were indicated in a trial-boring [TR 2625 6907] 1.2 km eastward of Coldharbour Sluice but elsewhere between the Isle of Thanet and the mainland an average of about 3 m appears to be general. Just east of Graveney an old record of some 9 m of alluvium suggests a deep channel there, while in a trial-boring [TR 0149 6163] at the creek in Faversham 4.9 m of grey and blue clay rested on gravel.

The alluvial deposits consist of organic silty clays and muds of variable consistency, diversified locally by sandy or gravelly beds, thin shell beds and peaty layers. Washings from adjacent strata tend to influence the upper parts, so that the top 1.2 to 1.5 m may be, for instance, a brownish clay like the London Clay, though soft darker or bluish deposits occur below. The base of the drift is in places a light loamy sand or may be gravelly or may consist of reworked adjacent solid materials, such as impure marl derived from the Chalk. SCAH

Details

In the Isle of Sheppey the small tract of alluvium between Warden and Leysdown includes marsh clay with a few plant remains, which was seen by Holmes, T. V. and Whitaker (1910, p. 486) to crop out from below the beach on the seaward side. Just east of Leysdown a very narrow fringe of alluvium borders the London Clay and contains material derived from it. In 1938 the following beds were exposed [TR 038 704] in front of the sea-wall.

A broad belt of alluvium forms Eastchurch, Harty and Leysdown Marshes but details were only observed bordering the Swale on the south side of the Isle of Harty, where up to 0.75 m of peaty clay or thin peaty soil with stones locally overlies brown re-sorted clay. Comparison with the original Ordnance Survey map shows that behind the growing shingle spit of Shell Ness consolidated marsh land has extended some 300 m southward since the beginning of the nineteenth century.

The Sheppey marsh clays have yielded marine shells such as Scrobicularia and vertebrate bones, usually blackened, including Cervus elaphus from a 'forest bed' probably of Holocene age. SCAH, SB

Alluvium which fringes the mainland from Luddenham Marshes to Seasalter Level also extends southward in several tongues along narrow valleys, where it frequently overlaps on to brickearth and in the shorter valleys generally dies out at a spring head. Black soil occurs where the inland parts are swampy. At gravel dredgings [TR 0110 6275] about 0.5 km ESE of Oare 0.9 to 1.8 m of brown and greenish loamy clay, containing re-deposited sand from the Thanet Beds, rested with an uneven base broadly channelled into Head Gravel. Certain mounds in the marshes at Seasalter Level are now known to be artificial and made up of a heavy clayey alluvium with humic layers, etc. (p. 96). From peaty alluvium below brown marsh clay at Graveney Marsh, Seasalter, A. S. Kennard recorded in MS a number of non-marine mollusca including material obtained by Mr J. P. T. Burchell. Listed are the brackish-water gastropod Hydrobia ventrosa, the fresh-water forms Lymnaea peregra and Planorbis crista, the land shell Vallonia excentrica and Limax sp.In addition, from a depth of 0.6 m, were abundant examples of Potamopyrgus jenkinsi, a Holocene species which appears to have changed its habitat from brackish to fresh-water only since the latter part of the last century.

A large part of Whitstable is built upon alluvium, protected artificially from erosion by the sea but liable to extensive flooding, as in the great storm of 1897 and in 1953. A tooth of Palaeoloxodon antiquus from a 'forest bed' at Whitstable appears to have come from a peaty deposit, below low-water mark, into which it had been washed from older drift during the formation of the Alluvium. The cycle of events was completed by erosion of alluvium and exposure of the bed to the action of the sea within historic time.

Alluvium of the stream at Swalecliffe is cut off and protected at the seaward end by the growth of a shingle spit.

In the valley of the Great Stour near Westbere grey and black variably peaty alluvial clay overlies darker grey clay and silt, in places sandy and with scattered white flints, thrown up in dredgings. Beyond Chislet Colliery the marshes have been modified by extensive flooding due to artificial causes. Black peaty clay occurs in the narrow tongue of alluvium east of Stodmarsh, but north-west of Grove the deposit is mainly a fairly stiff grey and buff clay with occasional patches of fine sand derived from Thanet Beds, which may lie at no great depth in some places.

The alluvium of the Little Stour valley is somewhat peaty and silty on the east side and eastward of Grove tends to change from grey and buff to a dark brown, more friable deposit. Whitaker recorded (in MS) that at Stourmouth, in the alluvium opposite his house, Mr G. Dowker found the marine shells Cardium edule and another bivalve, now referred to Scrobicularia plana, which is common round the British coasts at the present day. Fresh-water shells also occurred.

The broad alluvial tract of Chislet Marshes receives a short tongue from Shelvingford, on the west, and a much longer one occupying the lower reaches of the Sarre Penn and Rushbourne valleys. Near Tile Lodge the deposit is merely a thin reworked and laminated loam, paler than the true brickearth on which it rests; but below Chislet Park it has changed to a typical marshy clay or silt. Chislet Marshes carry pale grey and blue-grey silty and buff silty clay, locally shelly. While over the greater part it reflects the nature of the subjacent Thanet Beds, on the east, for instance, the ground tends to be a little chalky, and 0.8 km W of Down Barton includes also some flints and pebbles. Over 2.4 m of silt was proved 1.2 km NW of Chambers Wall. Buff and pale grey silt was observed nearly 1 km WSW of Coldharbour Sluice, while trial borings eastward of that point proved the following:

Another boring, beyond the sheet boundary, 450 m E of the last one, proved 6 m of similar alluvium the bottom 2.7 m of which was a soft brown marl resting on the Chalk.

According to Dr A. Bowes' list of fossil bones in the Herne Bay Museum Bos primigenius was obtained from Coldharbour. It presumably comes from an alluvial deposit.

Only a small proportion of the Alluvium eastward of Preston and Stourmouth appears within the area of the Faversham (273) Sheet. SCAH

Hillwash Head

Flandrian

The loams and hillwash placed in this group are purely local and are of recent origin, continuing to form at the present day. They occur on slopes or in valleys and are entirely related to the present topography.

The deposits may occur as a down-slope continuation of drift from the feather-edge of older drifts and so may show a variety of lithologies (with or without a gravelly admixture). Others are the weathering products of Tertiary sands or of London Clay, for example. Their thickness in the Faversham district does not exceed 4 m.

Only certain definable spreads have been shown on the geological map as Head, with a sepia colour to distinguish the drift from Head classified lithologically into brickearths and gravels. In the case of recent loams closely associated with brickearth it is not feasible to separate these litho-logically from the older deposit. A number of examples which have been distinguished on archaeological evidence are described with the account of Head Brickearth of the 3rd stage. Unlike that head brickearth, however, in distribution the Hillwash Head generally shows no particular preference for north-east facing slopes.

Much hillwash in Kent 'may well represent the result of soil erosion initiated by clearance and cultivation in late prehistoric times', as suggested by Kerney (1965, p. 270) in describing 'a silty Post-glacial hillwash containing fire-crackled stones and flint flakes of Neolithic or Bronze Age character' at Pegwell Bay in the Isle of Thanet. Kerney also points out that the distinction between such hillwash and the parent leached upper zone of underlying loess may not be clear unless a fossil soil marks its base. SCAH

Details

Two patches of Hillwash Head 1.2 km NE of Eastchurch and 0.8 km SW of Warden Point in the Isle of Sheppey lie at about 40 m and 46 m OD respectively. They consist largely of loam and sand wash from the Claygate Beds and Bagshot Beds and the deposit is 3.7 m thick at a point about 0.8 km NE of Eastchurch. Other hillside accumulations of sand, loam and re-sorted clay, with pebbles and flints, are present in places but are not shown on the map.

Westward of Faversham deposits of hillwash Head are fairly extensive at a number of points. Friable brown loam, locally flinty, becomes chalky as it passes on to Chalk in the broad valleys which trend northward to Luddenham Marshes. The drift is about 1 m thick, lies at the lowest topographic levels and grades into brickearth from which it is partly derived. About 0.4 km SW of Judd's Hill up to 3 m of very variable gravelly loam were seen in the road-cutting [TQ 9890 6035]. As was noted many years ago by Hughes (in MS) the base of the drift is irregular on a steep westerly slope and is made up of material derived from above. There it thins out against Thanet Beds and Head Gravel. Hillwash has tended to accumulate on the south-east side of the hills 1 km SW of Oare.

In the Great Stour valley flinty loam mantles the upper half of the steep hillside at Westbere and was seen to be up to 1.2 m thick at the top of the old pit [TR 1933 6113] 140 m ENE of the church.

Gravelly downwash fringes the north-eastern spurs of two gravel spreads near Breadland Farms and also occurs on the south and west side of Head Gravel patches at Knave's Ash and Hoath (Figure 7). Of rather more general influence on the soils of the Blean is the thin sandy wash (not distinguished on the map) that tends to connect patches of Head Gravel by extending impersistently down some of the gentle northerly or north-easterly slopes.

Gravelly soil covers some of the Thanet Beds between Highstead and Marshside and 1.2 m of gravel was proved in a well [TR 2190 6592] about 0.5 km ESE of the former.

Chalky rubble which occurs on the lower slopes of the western Isle of Thanet was seen pocketing the Chalk 100 m north of the inn at Sarre [TR 2576 6507], at the entrance to an old chalk pit. At the base of the drift, about 1.5 m down, Pomatias elegans appeared to occur in situ. SCAH

Blown Sand and Shingle

Flandrian

The only places where this deposit has been mapped and colour-ornamented on the geological map are at Warden and Shell Ness in the Isle of Sheppey. Accumulations of shingle along the mainland coast, however, are also strongly marked. In places they have become localised and compacted to form temporary or more or less permanent rocky bars, such as that known as the Street Stones [TR 114 680] at Whitstable, which is uncovered at low tide (Dowker, 1900, p. 10). The general direction of longshore drift is from east to west (Wheeler, 1902, p.295) and the content of the shingle is reflected to some extent by this, as well as governed by strictly local sources. Thus, for instance, there are differences east and west of the Whitstable 'Street', east of which there is a predominance of black ovoid pebbles derived from the Oldhaven Beds, which themselves form a projection of stones more or less corresponding to their lower outcrop at The Rand [TR 201 689] 0.5 km W of Oldhaven Gap; there, they in turn act as a barrier to sandstone slabs derived from the Thanet Beds farther east (Lacey, 1929, pp. 8, 9). The main bulk of flint in the shingle has its source either directly from the nearby Chalk of western Thanet and Faversham and of possible outcrops scoured out beneath the sea on the north-east, or from distant eroded Chalk, or from the wastage of extensive drift deposits on the former dissected land-surface that must once have extended far to the north. Sand was similarly derived from the foundering into the sea of Tertiary sands and of brickearths and other drifts. London Clay is the prime source of the marine alluvial muds. SCAH

Details

The shingle between Warden and Leysdown and in the bank which culminates at Shell Ness is sandy and shelly. The contents at the latter locality include also subangular and rounded flints and pebbles of septarian mudstone, and in the sandy parts are grains of limonite and a good deal of comminuted shell fragments. Hughes (in MS) noted that pebbles gave place southward to shells and in one location saw a section through about 1.8 m of material consisting almost entirely of cockle shells, with a few mussels and other bivalves. He explained their occurrence as 'probably due to a kind of back water as the wave action, travelling from the east, breaks on the north-east of Sheppey'. Prentice and others (1968, p. 1208) group these shell accumulations at the eastern end of the Swale with similar occurrences beside the Medway and in Essex, stating 'they form, as lag concentrates, after the fine material has been eroded and removed in suspension during bank erosion, and are ridges or dunes of low relief which migrate shorewards across the mud flats and saltings under wave attack'.

At Seasalter the shingle consists of abraded subangular flints, many of them brown, with Tertiary pebbles, lumps of ironstone and pebbles of buff septarian claystone. The very shelly beach is crowded with cockles, mussels and oysters, together with a few small gastropods. Towards Whitstable the coarse shingle and sand is much less shelly.

The Street Stones [TR 114 680] at Whitstable project about 1.6 km northward into Tankerton Bay and a small reef [TR 158 684] projects similarly for a much shorter distance at Hampton. Between these two points, at Swalecliffe a shingle 'ness' has formed by a spit growing westward, across the mouth of the stream, between the swiftly-eroding coast and Long Rock [TR 138 680], which when uncovered at low tide is seen to be 'a great bed of gravel-stone of various sizes' (Lacey, 1929, p.8).

The storm beach which has formed a bar across the marshes of the Wantsum strait extends continuously from Reculver eastward beyond Coldharbour Sluice to reach the Isle of Thanet, but it may be noted that the northern mouth of the Wantsum was not finally closed until walls joining Reculver to Chambers Wall were constructed at the end of the eighteenth century (Steers, 1964, p.337). The shingle consists of Tertiary pebbles (mostly from the Oldhaven Beds), dark green and black coated flints (from the basal Bullhead Bed of the Thanet Beds), blue, brown and red subangular flints, sand and shells. In 1938 there was a high sloping bank of pebbles and flints about 1.2 km E of Coldharbour Sluice. SCAH

Mounds in the Marshes

The marshes which border Sheppey and the Isle of Harty and those around Graveney and at Seasalter Level are variously diversified by clay mounds, frequently more than 50 m across, which rise more or less abruptly from the alluvium to heights commonly over 4.5 m. The larger and more important ones are shown on the geological map as London Clay. Hughes (in Whitaker, 1872, p. 292) saw on the north side of the Isle of Harty an opened mound which he thought to consist of London Clay and the products of its weathering. Although certain exceptionally large 'islands' are no doubt composed of solid clay disturbed only by normal erosion and surface slipping, for instance the smooth and regular Denly Hill [TR 062 634], near Graveney, which is about 0.4 km across and some 12 m high (Plate 8) the majority of them are probably artificial and consist of a heavy clayey alluvium. The latter is usually a re-worked paste of London Clay produced from the superficial weathering of that formation. The mounds tend to be distributed on the landward sides of the marshes. Examples around [TR 075 640], see p. 9 8] excavated in 1955 at Seasalter Level have proved to be artificial structures made from materials dug up from the marsh. Some were entirely removed by bulldozer and these, together with the whole group of mounds seen, or formerly to be seen, within 1.5 km E and NE of Denly Hill, have therefore also been deleted as London Clay 'inliers' from the later editions of the geological maps (compare, for example, the 1959 edition of the Faversham (273) Sheet with that of 1967). Regarding the somewhat similar grouping of mounds around [TR 061 641] in Graveney Marshes, no firm conclusions were to be drawn. The test that must be applied in any particular case of bulldozing down that modern agricultural requirements may demand will be the presence or absence of a solid (e.g. London Clay) formation core to the mound.

The little hills aligned along the ancient estuary of the Stour near Grove Ferry, dotted around the marsh near Chitty and set more or less in groups trending north-west and north in the 'Wantsum Strait' area all may be of artificial origin. The materials here are either Thanet Beds, the index colour of which has been given to them on the map, or sandy loam and fine silty clays comprising alluvium derived mainly from these beds. The larger mounds here tend to be elongated in a direction across the drainage courses and they commonly reach 0.4 km in length. Superficially there appears to be a particularly close relationship hereabouts to the artificially excavated courses of some streams and ditches, and it is possible that the hillocks may contain original sand from the Thanet Beds as well as purely drift materials, all depending upon the depth and location of the substance dug out. On the whole, in this region it seems less likely that the mounds are original erosional features, a not unnatural conclusion, too, in regard to such soft friable sands, loams, silts and clays that make up the lower part of the Thanet Beds. Some larger 'rises' in the Stour marshes beyond the sheet-boundary to the east, however, are in fact denuded hills of Thanet Beds (White, 1928, p. 51).

As Steers (1964, pp. 396–397, 402, 679–680) has recalled, there are in the Sheppey area between the Medway and Shell Ness alone 'up to two hundred small mounds, the Kentish counterpart of the Red Hills of Essex'. Professor Steers summarised the conclusions of Linder (1940, 1941) that led to his recognition that the Red Hills of Canvey showed 'occupation at successive periods of a burnt earth surface subsiding at an average rate of about eight inches (0.2 m) per century'. Unlike the Kentish hillocks, however, these Essex mounds are thought to have been subjected to a gradual sinking for some 2000 years that has led to their almost complete submergence beneath the marsh; they were probably the still recognisable hillocks of the late sixteenth century when Camden wrote. Evidence of Romano-British occupation in the first and second centuries AD is not matched by the Kentish mounds, which have locally yielded medieval indicators, as at Seasalter Level (see below). At this locality, too, the hillocks consisted of more or less uniform clay, with oyster shells, burnt layers and pottery fragments, etc., and they are evidently dumps of excavated material.

Whether or not such dumps are exceptional is uncertain; in various localities there are indications of planned arrangement of mounds or groups of mounds, thrown up from the excavation, enlargement, deepening or general maintenance of old, commonly sinuous, watercourses, to form small tracts of elevated ground, each in particular dyke-enclosed fields. Cattle and sheep use the mounds as refuges from bog, flood and inundation. There are in addition hundreds of tiny knolls a few metres across, for instance in Graveney and Luddenham Marshes, that serve a similar purpose and are modern heaps made from digging out anthills, molehills, turf or dredgings from runnels.

Although it is evident that many mounds do not conform to the erosional origin illustrated for the Sheppey marshes by Hughes (in Whitaker, 1872, p. 293, figs. 74–76) it is also, as he too indicated, clearly unnecessary to invoke explanation either as possible defensive positions or as sepulchral monuments.

Mounds considered as relics of early saltworks

At Seasalter it is known from charters of 785 that there were saltpans, conveniently adjacent to the Blean woodland which provided charcoal fuel for evaporating the salt, 'silvam afundantur ad coquendam sal' (Ward, 1944, p. 51). The old mouth of the Wantsum was another area where, at the time of the Domesday Book, there were a great number of saltpans. Salt, in fact, was a commodity very much in demand in the days when there were no winter feeds to preserve stock alive through the worst months of the year. Ward (1944, pp. 52–53) also mentions other early accounts of salt works, near Faversham, but does not relate any citation specifically to the various mound-rich areas.

Investigations at Seasalter Level in 1955 (Thompson, 1957, pp. 44–67) were the first in the Faversham area to prove the age of a group of mounds and also to suggest a very strong association with salt-panning; the conclusions have an important bearing on the geological interpretation (see above, p. 96). Five mounds around [TR 075 640] were bulldozed and one of them at [TR 076 643] subjected to four weeks' study excavation. They were completely levelled for ploughing, and they proved to contain no solid London Clay but to consist of a brown tenacious silty marsh clay heaped over a 'core' of bluish grey unweathered alluvium that remained as an artificially protected relic of the original marshland surface. Exceptionally large mounds at [TR 070 637] and [TR 072 637] (not bulldozed or excavated) showed strikingly hummocky outlines and steep abrupt slopes on their seaward sides when observed in 1955; Dr J. R. Earp mapped the area in 1938 and had at the time every good reason to suppose them to be natural 'inliers' in the marsh.

In the mounds dug away there were no signs of stratification apart from indications of outward-spreading wash and rubble tips of oyster shells, with a few whelks, fanning out from old mound surfaces on to the surrounding marsh. There were, however, numerous burnt layers or patches and inclusions of charcoal (in the brown clay), as well as fragments of medieval pottery, a medieval leather boot and other objects; there were the remains of small rectangular pits containing vegetable matter, some hurdles, and sticks arranged to form narrow paths, fully recorded at the site and studied in detail.

The mounds of the several groups in Graveney Marshes and at Seasalter Level tend to be elongated, up to 150 m long and 6 m high, and vary in outline with the steeper slopes commonly on the seaward side and carrying two or more humps on that side. Thompson was able to conclude that the mounds he had investigated were probably thrown up some time before 1325, when construction of the sea wall is known to have been completed (the present beach of cockle shells bordering the Oaze extends beneath it). They may have served as refuges for sheep and cattle, for example from spring tides, in the years preceding and also soon after this event; but the amounts of burnt material in the upper parts, and the presence of the square pits and other structures, have led to the conclusion that the mounds are primarily the relics of medieval salt-workings.

Salterns have been described by Smith (1918) at the Roman or Iron Age sites of the Red Hills in Essex; and further, taller, mounds thereabouts have been shown to be medieval (Essex Arch. Soc. 1925). Thompson has pointed out that for Sheppey mounds the local dialect word 'coterells', though suggestive of cattle refugees, may equally derive from evaporation works or 'salt coots', a term used by Leland in his early tenth century Itinerary. From the early fourteenth century onwards it is known that marsh salt works sometimes led to the accumulation of mounds. As the first established salterns became silted up or cluttered with excavated mud and debris, and further ones were dug nearer the sea, it was natural for the old sites to become pasture with ready-made hillocks.

The siting of the mounds at Seasalter is thought to have been planned to avoid the worst effects of inundation. If the sea wall were removed the area by the old stream courses would be flooded at every tide, an effect illustrated rather strikingly in the great flood of 1953. Possibly the old stream courses were also cleaned from time to time and thus also provided material for the mounds. As to the method of preparing salt, probably evaporation by the sun was limited climatically and a process of boiling in receptacles was therefore used; the brine would first have been drawn out from the earth or mud impregnated with the common salt.

Mr Thompson and his colleagues were impressed by the general similarity, and their relationship to old water channels, of the coterells in the marshes between the Isle of Harty and Sheppey to the mounds on Seasalter Level. Noted also (Thompson, 1957, pp. 63–64) were the large mounds that occur in profusion in the northern part of the valley of the Wantsum. Some of these that have been bulldozed showed burnt patches at all levels and yielded sherds of fifteen-century pottery. This area was not imbanked until after Elizabethan times, so the marshes there were presumably still tidal the century before.

Summary of geological implications

When for its agricultural value, officers of the Soil Survey of Great Britain (1956, p. 19) were in 1955 requested to carry out an 'examination of a number of hillocks on the Marsh levels at Seasalter which had been mapped by the Geological Survey as outliners [sic] of the London Clay', their conclusions in the absence of excavation, were unspecific; it was suggested that micropalaeontological examination would be needed to distinguish between London Clay and Alluvium artificially raised. In areas where many occupation sites are documented it is tempting to regard all mounds sterile of human indicators (such as briquetage and pottery in the Canvey district of Essex) as of natural origin; but the possibility of cremation burial in the side of already existing mounds cannot be overlooked.

With a view to making some overall geological assessment of mounds in the Kent marshes at Sheppey, Isle of Harty, Faversham, Graveney, Seasalter, the Stour Valley, the Wantsum area and Reculver, Dr S. Buchan and Mr Holmes carried out a reconnaissance in July 1957, using an auger and making comparisons with standard exposures outside the marsh areas. The conclusions are an attempt to guide the investigator on the distinctions beween natural and artificial mounds, bearing in mind also the historical and archaeological evidence, as described above.

Natural mounds

London Clay forms large mounds or isolated hills that are generally smooth in outline apart from small-scale landslip scars; Tertiary sands (Thanet Beds) similarly produce large mounds or 'islands' by the natural subaerial erosion of streams, periglacial action and surface weathering, but they tend more to be elongate and variable in height and outline. Marine erosion may in some cases have provided a stimulus or modification, as described by Hughes (in Whitaker, 1872, pp. 292–293), especially during a period of submergence.

Indicators of natural in situ mounds are: fossil remains, especially mollusca (microfossils on their own are liable to be misleading, derived foraminifera, for example, being readily transferred into drift or man-made deposits); texture and composition, e.g. uncontaminated glauconitic sand of the Thanet Beds, hard shaly clay of the London Clay; signs of stratification, e.g. in Thanet Beds fine loams and sands; content, e.g. septaria, selenite and pyrite in the London Clay; topographical situation in relation to known outcrops, e.g. quite small hillocks may be the tips of an eroded hillside topography ('drowned') near the inner marsh limit.

Observations require to be qualified wherever a mantle of superficial material (e.g. of brickearth, gravel, head or rainwash) may occur.

Artificial mounds

These may be anything from 0.3 to 6.0 m high, but all but the smallest tend to have a distinctly knoll-like, and perhaps also an abrupt, outline. Their unevenness and the presence of tip or dump features are apparent in aerial photographs. Where supported only by underlying marsh deposits, heavy ground vibration is an immediate indicator; this was a notable effect at Seasalter Level adjoining the railway line. The presence of extraneous materials and contamination may be detectable.

Modern heaps made from clods of earth dumped on the marsh may be fairly obvious; though quickly denuded and reduced in prominence they are usually penetrable with an auger into underlying marsh clay. In the Wantsum marshes some Thanet Beds mounds that are natural hills also carry low knolls of made ground yielding oysters, carbonaceous matter and mottled red and yellow burnt clay or marl (cf. p. 97). Human occupation and use of existing hillocks might be expected to have been fairly general.

The relationship to old stream courses that has been held to suggest an artificial origin may not apply to all such mounds; natural valley erosion of sufficient antiquity could produce similar results.

General note

In practice it may be difficult to prove a solid core to a mound without resort to excavation. A mantle of weathering products may be almost indistinguishable to some metres from the surface. Dr Buchan recorded a clay-pit section in the London Clay of Sheppey on the Chatham (272) Sheet that had become entirely weathered within ten years to present a disturbed face of clay rubble much like that of most of the clayey marsh mounds.

The small clod mounds that are clearly artificial were indicated by Dr Earp and Mr Holmes in the six-inch survey but are not given a colour on the geological maps. SCAH

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Chapter 10 Coast erosion and landslips

Introduction

There is a close interrelationship between erosion of the coast and the processes of landslipping that are initiated by it and which produce by far the strongest landslip disturbances. A factor that in turn originates the most powerful erosion is tidal surge. The great surge and inundation of 1953 (Robinson, 1953), the most important one affecting south-east England in modern times, was observed to have such profound effects (causing loss of land and widespread damage) that a renewed impetus was given to coastal research and a considerable amount of further protection work in critical areas has since been carried out by civil engineers. An account of documentation, research and remedial measures since the 1953 floods follows the outline account here given first.

The coastlines of the Isle of Sheppey and of the mainland illustrate strikingly the action of erosion at the sea-margin. Cliffs formed of Thanet, Woolwich and Oldhaven beds, near Reculver, are steep and sharply eroded by wind and waves (Plate 1), (Plate 2), the loose, fine-grained Oldhaven sand being particularly liable to be blown away by strong winds. Elsewhere, the London Clay cliffs exhibit in varying degrees the phenomena of rapid disintegration consequent upon shrinkage cracking followed by frost action and the circulation of ground water as seepages or spasmodic torrential flows (Plate 9), (Plate10). The main effect of the sea in these cases is to encourage further erosion by removal of the fallen material, which has a temporary protective influence, but where the amount of slipping and cliff-fall is sufficiently extensive a relatively stable condition of semi-permanent landslip topography has been reached, notably on the north-facing coast of Sheppey, at Tankerton and near Herne Bay. At the last two places advantage has been taken of these conditions in securing their permanence by coastal protection and artificial drainage works, particularly for storm-water relief. Smaller landslips are also shown on the map: at Cleve Hill, near Graveney, more than 0.8 km from the sea, at Seasalter and at the more recently foundered cliff that cuts Stud Hill, near Swalecliffe.

Landslips accompany coast erosion and by their relative states of instability or maturity are indicative of the strength of the process in particular localities. Their mode of formation was appreciated many years ago by Bingham (1861, p. 92), who quoted an account of slipping at Warden Point in 1859 which emphasised the gradual nature of subsidence shoreward once dislocation at the cliff edge has begun. Whitaker (1872, p. 387) cited Hughes' observations of landslipping in Sheppey, where cracks in the London Clay he considered to collect surface water which not only softens the clay at the bottom but adds appreciably to its weight. 'If the crack is near the cliff the half detached mass being now heavier, owing to the addition of the water, while the cohesion of the attached portion is lessened, slips down to the shore below, sometimes almost unbroken, sometimes breaking off by parallel cracks into a series of terraces, or even in part creeping down among the fallen stiffer masses, as a glacier-like mud flow.' As long as the sea washes away this debris from the base of the cliff the process may be repeated. Dewey and others (1925, p. 284) pointed out analogies with glacial features shown by certain slip-features of the London Clay cliffs east of Herne Bay to which Wooldridge had called their attention. Mud-flows carrying 'morainic' septarian material show 'differential movements at the centre and sides' and may expand into broad 'deltas' on the foreshore. In notes on the erosion of these Beltinge cliffs Lacey (1929, p. 10; figs. 5,6,7,8, pl. 1) added an account of the action of springs on landslip formation, especially where they arise in hollows of the clay at its junction with overlying drift. The gullies of gravel and brickearth to which he refers, however, may have been much older original drift features, unconnected with coast erosion except in so far as they were exposed by it and tend to determine the location of northward-flowing spring water which can cause subsequent movement by collapse in situ. From Ordnance Survey maps Lacey (1929) demonstrated striking changes in the cliffs, between 1872 and 1906, which appear largely the result of failure to maintain adequate artificial surface drainage. At Bishopstone, Whitaker (in MS) noted that landslips he saw about 1894 produced cascades of London Clay material over cliffs consisting of undisturbed sands in their lower part. Near Warden Point, in the Isle of Sheppey, anomalous steep bedding observed by Davis and Elliott (1951, p. 269; 1954, p. 383) at Barrows Brook is probably connected with flow of the stream, for visible slumping movement in the London Clay here has been observed in wet weather; landslip, moreover, was mapped inland for 250 m on the south-east side of the gully. On the Sheppey coast the tumbled and brecciated masses of dark grey shale and clay frequently carry admixed yellow loam and sand, derived from drift or from Claygate and Bagshot beds, while large masses of London Clay detached en bloc are frequently bounded by slickensided curving slide planes. Spring water from the Claygate and Bagshot Beds affects movement of the London Clay in a manner similar to water from drift elsewhere (Holmes, T.V. and Whitaker, 1910, p.486).

Of inland slips there are incipient small disturbances over many hilly tracts of London Clay country, but they are not significant enough to be shown on the map. The example at Cleve Hill appears to have been initiated as coastal landslip before construction of the sea wall and the completed growth of Cleve and Graveney Marshes excluded tidal influence.

The average annual loss of land by erosion at the unstabilised parts of the coast from Sheppey to Reculver has been about 1.8 m. This figure is deduced from observations and descriptions, of varying accuracy, dating from Roman times to the present day; the amount has varied much from place to place and at different periods, but there is sufficient evidence from recent years to establish that this average wastage is about the normal and contrasts with an average of 0.6 m per year waste of the more resistant Chalk cliffs between the North Foreland and Reculver that was recorded by Dowker (1881, p. 3).

In the Isle of Sheppey an average annual loss along 9 km of coast was 1.2 m between the years 1865 and 1906, but at Warden Point the average loss reached 3.0 m (Steers, 1953, p. 26; 1964, p. 402). Erosion at the northern cliff edge has continued even though some of the landslipped cliffs reached a state of relative stability after the artificial stripping of the foreshore, beach and cliffs for septaria and pyrites ceased to be profitable and was not revived after 1914 (Davis, 1936, p. 343). Davis points out that a form of iron pan produced from pyritic detritus is resistant to wave action and that 'large falls of cliff, when they have attained repose, stand for 12 or more years before they are so reduced as to cease to act as buttresses to the main cliff'. The cliffs at Warden Point and to the south-east have shown the most striking changes of the Sheppey coastline (Holmes, 1972, p. 135, fig. 2). Approximate cliff positions can be estimated from Ordnance Survey maps, from data in some published accounts and from aerial photographs. Whereas the general loss of the Warden cliffs has been at least 2.1 m per year, however, aerial photos in 1946 and 1953 revealed only slight local changes of outline within that period. At Warden Bay some parts were almost stable until about 1863 but were followed then by the loss of 50 to 100 m; this is the approximate amount lost since 1819 by the tract of alluvium and shingle between Warden and Leysdown that represents only about 0.6 m per year. But strong erosion in comparatively recent years at an intermediate locality has now completely removed the former jetty at Warden, where Davis pointed out that concrete fortifications were washed away in 1933 and the cliff was measurably receding. Numerous reports on erosion in Sheppey have emphasised the magnitude which it has assumed from time to time. Hughes (in Whitaker, 1872, p. 291) cited evidence for a loss of about 200 m from 1816 to the time he was writing, when the church at Warden Point still remained standing on the edge of the cliff. This rate of decay works out at about 3.7 m per year, and the church and churchyard had all gone before 1898 (Whitaker, Holmes, T.V. and Shrubsole, 1898, p. 461). Further depredations were noted by Holmes, T.V. and Whitaker (1910, p. 486), while Davis and Elliott (1951, p. 269) have mentioned the striking contrast between the recent coastline and its corresponding topography in 1861. Wheeler (1902, p. 297) states that not only did a coastguard house near Warden Church disappear between 1856 and 1859 but also that three coastguard stations had to be pulled down in the following years. In Whitstable Bay there were formerly extensive mud shore deposits upon which grew herbage and grass but these have gradually been eroded away by the sea; most of the mud flats at Seasalter had been carried away by the waves even before the high tide of 1897 (Dowker, 1900, pp. 10, 12).

While the landslipped cliffs at Tankerton have been relatively stable since before 1872, at Swalecliffe and Stud Hill erosion was from time to time particularly active (Holmes, 1972, p. 135, fig. 3). The history of this coastline from the eighteenth century is represented in Holmes' diagram, for which later information was drawn from Ordnance Survey maps, from field observations made in 1938, 1939 and 1946, and from aerial photographs in 1946 and 1953. Erosion has been concentrated in the development of bays westward of the stable areas at Long Rock, near Swalecliffe and at Hampton Point. Indeed, coastal protection works at the latter place may have assisted in the establishment of an exceptionally strong phase of erosion at Stud Hill. Since the eighteenth century the coast there has lost no less than 275 m, an average of over 1.5 m per year, while between 1872 and 1953 the average annual loss has been as much as 2.5 m. Severe denudation was seen in progress at Stud Hill in 1946 (Plate 9) and since that date further depredations at the cliff edge continued. The rate of erosion at Swalecliffe shows an average of about 1.4 m per year, though during a period of ten years Worsfold (1926, p. 326) noted wastage of about 3 m per year. Taken over a long period, from about 1862 onwards, though, it is evident that erosion at Sheppey must have much outstripped that on the mainland, for by 1925 the Nore Light, off Sheppey, first became visible in line from Tankerton (Worsfold, 1955, p. 165). The peaks of increased erosional activity are clearly localised and cyclical in occurrence.

Herne Bay has a stable frontage, artificially protected, by groynes, etc., from the sea which otherwise would no doubt sooner or later have attacked the promontory of Hampton Point. Extensive accumulation of shingle on the eastern side of the old pier at Hampton (Wheeler, 1902, p.296) has emphasised the significance of currents and shingle movement from east to west along this part of the coast. Wheeler compared the low-water marks at Herne Bay shown on Ordnance Survey maps of 1872 and 1896, during which period the position approached 300 to 400 m nearer the parade. This represents a scouring action by currents accounting for a wastage of 14.6 m of beach per year, an extreme condition which would normally be balanced by fallen debris accumulated from cliff and shore wastage in the absence of artificial coastal protection. As noted by Richardson (1841, p. 213) and mentioned further by Lyell (1875, p. 527) and Willson (1902, p. 144), Herne Bay formerly consisted of an upper and a lower bay divided by a small promontory which has been swept away by the sea. The name of the place is now, however, hardly more appropriate than that of Oldhaven Gap, some 3 km to the east, where erosion has removed all vestiges of the harbour from which the glen or ravine in the cliffs took its original name of 'Old Haven' (Richardson, 1834, p. 78; 1841, p. 213). At Beltinge (Lacey, 1929, pp. 11, 61, figs. 5, 6) there was a loss of 30 m of land between 1872 and 1906 (about 1 m per year) but between Herne Bay and Oldhaven Gap generally the heavily landslipped cliffs were unaffected by serious recession until 1953 (Plate 10). Denudation has latterly not much affected the cliffs immediately east of the Gap, where, after a loss of some 55 m during the last century, the cliffs became more or less stabilised during the next fifty years.

Erosion of the coast at Reculver since Roman times (Holmes, 1972, pp. 131–135, fig. 1, pl. 12) has been a subject for study ever since the comments of Lyell (1830, p. 275; 1875, p. 528), Mitchell (1833, p. 7) and Smith (1850, p. 192). These writers drew significant information from a variety of earlier accounts, while later contributors who have summarised the history of the Reculver coastline include Gibb (1862, p. 330), Whitaker and Dowker (1885, p. 171), Wheeler (1902, p. 295), Wilson (1902, p. 142), Worsfold (1926, p. 326) and Jessup (1930, p. 189). One erosion estimate attributed to Worsfold (1955, p. 165) is, however, exaggerated and arises from a mistaken interpretation of Leland's statement that in the sixteenth century (about 1540) Reculver stood 'wythin a quarter of a myle, or a little more, of the se syde' (see Smith, 1850, p. 192). Although Smith (1850, p. 194) thought that Leland's distance could amount perhaps to half a mile (0.8 km) in standard usage, that is the limit of possible adjustment, and the implied erosion rate of some 2.5 m per annum is unlikely to have persisted for a long period. Generally speaking the average erosion loss at Reculver was probably not more than 1 m per annum, which practically ceased with artificial stabilisation early in the nineteenth century. The diagrammatic map of probable and possible coastlines given by Holmes (1972) is based almost entirely on information contained in the above accounts, but a comparison of modern maps with the earliest Ordnance Survey one-inch and six-inch maps was also made. The estimated position of the Roman coast can hardly have been less than 1.5 km from the present one; and the submerged Pudding Pan 'rock' (? an artificial structure) now as much as 5 km out from Herne Bay, then possibly stood on land (perhaps as a peninsula), with an island at the Pan Sand farther northeast (see Steers, 1964, p. 401). Whether the presence of such an island was indeed the origin of the Caunos, Counos, Couennos or Convennos ascribed to Ptolemy (A.D. 160) and used by other early geographers is uncertain; some writers' allocation of the name, following Camden (1586), to Canvey Island, in Essex, is, however, unconvincing on topographical evidence from about 1360 (the anonymous 'Gough' Map of Great Britain) onwards.

Eastward of Reculver the coastline is an erosion-protected stretch of Wantsum marshes for nearly 5 km. Historically, the Isle of Thanet on the east gradually ceased to be a true island as the Wantsum Channel became silted up; it is recorded that the last ship sailed the channel in 1672. In the great storm and tidal surge of 1953 Thanet for a few days became a true island again when inundation broke through the sea wall embankment (see McRae and Burnham, 1973, pp. 37, 131).

Research and coastal evolution since 1953

Accounts of the coastal changes related to landslips are embodied very fully in the published researches of Hutchinson (1967, 1968a, 1970, 1973) and Hutchinson and Hughes (1968). Hutchinson (1965a) presented a dissertation on cliff stability to the University of Cambridge in 1965 and has since collaborated extensively with civil engineers, palaeontologists and physiographers and prepared for the Building Research Station, Watford, a detailed survey of coastal landslides in south-east England (Hutchinson, 1965b). His descriptive catalogue for Kent has provided the basis for the summary given below (p. 108).

Many striking features were still available for study in 1966 and descriptions may be referred to in the account of a field meeting on the coastal landslides of Kent (Hutchinson, 1968a, pp. 227–232). This field meeting of the Geologists' Association had been preceded on 29 July 1961 by a short visit to Sheppey that commemorated the first visit of the Association there on 1 August 1861. The loss of land during the hundred years was most forcefully demonstrated. At Warden Point the disturbances are rotational landslips, bench-shaped in plan, and most involve base failure. Their whole cycle of degradation lies between thirty and forty years. A failure had occurred about 1945. Another very strong slip was initiated in about 1950 but by 1966 the dominant features hereabouts were the extensive mudslides and the effects of marine erosion; the latter was removing in situ London Clay from beneath the aretes bordering slips, disturbed London Clay from the landslip masses, and mudslide material from each side of the latter. By contrast, the freely degrading slopes of London Clay in the Isle of Harty, where removal of debris at the foot has ceased, now show only shallow landsliding, predominantly of successive rotational type (Hutchinson, 1968b), giving a low slope inclination that will eventually become naturally stabilised when degraded probably to about 8°. East of Herne Bay, though the average recession of the cliffs has in recent years been less than 1.5 m per annum, landslipping has occurred that has caused considerable wastage and damage, notably at the impressive Miramar slip on Beltinge Cliff, which took place on 4 February 1953, just after the tidal surge of that winter. At The Lees, about 1.5 km E of Herne Bay pier, however, conditions of moderate marine erosion on the intensely fissured stiff London Clay have produced only shallow mass movements, 'characterized by the formation of a succession of corries in the cliff slopes, each occupied by a mudflow and bounded by aretes of dried London Clay' (Hutchinson, 1968a, p. 230). In contrast to conditions at Warden Point, Isle of Sheppey, 'here virtually the only material eroded by the sea is from the tongues of the mudflows', and this length of cliff has therefore remained insufficiently steepened for deep-seated rotational landslipping to take place. It was only because of intensified erosion at the cliff foot as a result of the 1953 storm-waves and high sea levels that similar moderate erosion conditions were for a time so dramatically altered farther east at Miramar.

Hutchinson has distinguished the three cases of response of London Clay cliffs to differing rates of erosion (Hutchin son, 1973, pp. 221–239) and allocated examples that fall within the Faversham area as follows, with many illustrated details of each mechanism. The average rate of recession of the cliff-edge is given in metres per year for each example.

• 1 Erosion broadly in balance with weathering:
• Beltinge (E), 1961–65; 0.40
• Beltinge (W), 1933–66; 0.26
• The Lees (E), 1933–66; 0.26
• The Lees (W), 1933–66, 0.32
• 2 Erosion more rapid than weathering:
• Warden Point (E), 1865–1964; 2.15
• Warden Point, 1865–1964; 1.5
• Warden Point (W), 1865–1964; 1.55
• Barrows Brook, 1865–1964; 1.4
• Fletcher Battery, 1865–1964; 0.95
• Spider's Castle, 1864–1963; 1.3
• Bugsby's Hole, 1864–1963; 0.9

All the above are located on the north coast of the Isle of Sheppey where documentation of many landslides of various ages has enabled Prof. Hutchinson to recognise a consistent pattern of cyclic behaviour (Hutchinson, 1973, fig. 5, p. 227; pp. 228–230). Detailed work on some North Sheppey mudslides is reported by Hutchinson and Bhandari (1971).

• 3 Zero Erosion:
• Miramar
• Queen's Avenue Slip

Cessation of erosion may have natural (e.g. cliff abandonment) or artificial causes (e.g. defences against toe erosion). In the case of the Miramar slip its rear scarp had an inclination of 73° in February 1953, reduced to a mere 22° by March 1968.

Research specifically related to recent coastal change and sea defences has provided comparisons of clifffine recession for the London Clay of north Kent with that for Chalk and Gault localities in south-east England (May, 1966; McRae and Burnham, 1973, p. 36). Whereas over a period of 79 years' record of cliff-top change in unprotected (1962) areas, between 0.69 and 0.97 m (Sheppey) of London Clay have been lost on average annually, the losses in east Kent and at Folkestone are calculated as between 0.09 and 0.28 m (except 0.75 m for southern Thanet and St Margaret's Bay to Kingsdown), observed over slightly longer periods.

Erosion of the coast between Whitstable and Reculver was the subject of a special study by So (1967), in which are given valuable documentation of rates of cliff recession, and of landslipping, and an extensive bibliography. In discussion of So's account, Holmes (1969) drew attention to the evolution of this part of the north Kent coastline by embayments that have been controlled basically by the incidence of relatively unresistant drift and sandy Tertiary deposits as well as by the development of landslipping. Both So and Holmes note the strong tendency for these relatively rapid recessions to be accentuated on the eastern sides of the embayments as at Whitstable, Swalecliffe, Hampton and, to some extent, eastward of Beltinge. The London Clay cliffs have shown both that landsliding is a major factor in reducing a promontory undergoing marine attack, as at Stud Hill, and that coastal protection works, as at Tanker-ton and Hampton, can effectively control, if not completely eliminate, the dual and reciprocal processes of such marine erosion and coastal mass movement. The early history of landslipping east of Herne Bay (So, 1967, pp. 478–479) includes impressive examples in 1883, 1896, 1900, 1903 and between 1907 and 1933. Later instances mentioned by So are those at Stud Hill, east of the coastguard station, in 1946, a slip 'on trimmed and drained slopes in the eastern part of the Downs' (just east of Herne Bay) in the winter of 1957, and the effects of the 1953 storm at Stud Hill and east of Herne Bay. Minor disturbances at Tanker-ton (1958, 1960) and at Herne Bay (1952) took place in spite of existing protective measures. Of the many coastal changes cited (So, 1967, pp. 479–481) recession just west of Hampton was said to be as much as 4.7 m annually between 1898 and 1931. 'Immediately eastward the rate fell abruptly to 21 ft [0.8 m] and then gradually increased to over 3 ft (0.9 m) before it diminished again towards Reculver'. So adds that 'from 1931 to 1939 coast recession increased in rate eastward from 81- ft (2.7 m) east of Tankerton Bay to a maximum of 11 ft (3.4 m) at Stud Hill'.

In a general discussion of processes (So, 1967, pp. 481– 488), the role of excessive water in landslipping is recognised as important, as also are extremes of high and low water (the latter relieving pressure from the cliff foot), excessive rainfall, shrinkage cracks and nocturnal cooling. So gives a summary of storm surges since 1872. That such flooding, especially when associated with onshore winds or spring tides, has such a marked effect upon slipping is readily borne out by a correlation between the frequency of floods and the incidence of landslipping recorded over the years up to 1953. In concluding that coastal erosion of Lower London Tertiaries is less rapid than that of London Clay (evident because landslipping at the present day governs only the London Clay coast), however, So's argument omits to consider the trends of coastal evolution throughout the Quaternary. Even in recent historic time (see buncombe, 1784, p. 84; Holmes, 1969, p.269) erosion of the soft sandy cliffs of Thanet Beds and Woolwich Beds was extremely rapid, though not, of course, showing the phases of landslip typically exhibited by compact and tenacious clays such as London Clay. The Thanet Beds northward of the present Wantsum Strait alluvium must have yielded very quickly to marine erosion north-west of the Isle of Thanet. Similarly, the area of the Swale and Whitstable Bay, carrying alluvial muds and sandy gravels derived largely from denuded Lower London Tertiary beds as well as from the London Clay, was a region of rapid erosion, bordering which a promontory that now is reduced to form eastern Sheppey (D'Olier, 1972, pp. 125–129) has been the major target for marine erosion over some 8000 years (see p. 93).

Recent research on sediment transport in the Thames and Medway estuaries (Prentice and others, 1968, p. 1207) has shown that, where unprotected (e.g. artificially) 'the salt-marsh edge is still retreating, and the mud-flat surface is being degraded'. An important line of evidence is afforded by the surface occurrence of the articulated valves of dead Mya arenaria and Scrobicularia plana, burrowing forms which are normally emplaced at least 0.25 m down in sediment; barnacle epifaunas, zoned according to age, commonly confirm this erosional trend, for 'the oldest barnacles occur at the top of the valve and new spat at the sediment interface'.

Coastal protection schemes

Loss of agricultural land and amenities consequent upon landslipping and erosion is a process that is ultimately completed by natural causes, i.e. by weathering (Hutchinson, 1973, pp. 235–237). As Hutchinson concludes 'efforts must be directed primarily towards the control of erosion', but even if toe erosion is halted entirely 'cliffs of fissured clay will continue to degrade for a period which may extend into thousands of years'. As most of the coastline in the area of the Faversham (273) Sheet consists of London Clay, the protective measures adopted in a number of localities have a good deal in common and all are concerned with the location of slip surfaces and the control or diversion of natural drainage; the effects of tidal surge and scour are minimised mainly by the construction of concrete aprons.

Stability studies over the length of coast between Whitstable and Beltinge Cliff east of Herne Bay have been instrumental in the design of various protective works. A useful list of some of the many civil engineers' reports from 1953 onwards is published by So (1967, pp. 489–490). An adjunct to other evidence in determining the position of planes of discontinuity in either new or older degraded landslips is the use of stratigraphical micropalaeontology. Trial boring in the area east of Herne Bay that was previously not effectively interpretable gave clear results when a zonal scheme of microfossils was applied (see also p. 52); for this purpose, in 1963 a standard sequence through undisturbed London Clay into Oldhaven Beds was first established (Hutchinson and Hughes, 1968). Later, in 1970, these investigations were followed up by hundreds of further boreholes. Arenaceous foraminifera such as Verneuilina, calcareous ones, such as Marginulina wetherellii, and diatoms, such as Coscinodiscus, provided readily identifiable horizons, from the position of which displacements of up to nearly 18 m were calculated. It is of interest to note that weathered selenite occurred as low in the clay as 14.2 m below surface and may therefore be a general indicator of deeply disturbed ground. These researches were carried out at the Institute of Geological Sciences.

For a list of sea defence works that have been undertaken along the Kent coast May (1966) is a source to be consulted. Wyllie (in McRae and Burnham, 1973, p. 131) has summarised the present-day position where cliffs are absent: 'alluvial lowlands are protected from tidal inundation by sea walls of various forms but basically most consist of massive earth embankments with concrete protection'. After the 1953 flooding much restoration work had to be carried out 'and in Kent alone cost about £10 000 000 and were carried out to a standard such that sea walls can be expected to withstand a storm and surge tide of the 1953 severity'. In the notes that follow, details enumerated by Hutchinson (1968, p.236, References; and see catalogue below, pp. 108–109) have been drawn upon.

The actively eroding north coast of Sheppey north and west of Warden is little inhabited and any likelihood of development near to the cliff edge has so far been insufficient to create a demand for coastal protection works. At Warden itself, however, groynes have been constructed in front of the low cliffs and a sea wall to protect the alluvial marsh area.

On the mainland, at Seasalter, where predominantly westerly littoral drift is evident, the stumps of old groynes that project through the beach on the west are relics of old protection works that have now been superseded by a concrete sea wall with groynes extending along most of the, now effectively stabilised, Seasalter frontage. It was hereabouts that on the occasion of the great storm surge at Seasalter and Whitstable in 1897 it became so noticeable that there had been 'a loss of shore half a furlong [100 m] broad, and three-quarters of a mile [1.2 km] in length since the 6-inch Ordnance map (1872) was made' (Dowker, 1900, p. 10).

The west end of Tankerton is defended by a low concrete toe wall and groynes; more complex concrete works and artificial sloping with 'herring-bone drainage' have been carried out along the cliffs to the east with considerable success, but necessitating further attention from time to time, e.g. after storm damage in November 1961 (see also So, 1967, pp. 477, 479). Worsfold (1926, pp. 338, 330, pl. 16, fig. 29; 1927, p. 224, pls. i, ii) gives a plan and geological section of the cliffs at Swalecliffe, east of Priest and Sow corner, Tankerton [TR 127 673] as they were in 1923, superimposed upon the topography of the 1907 Ordnance Survey 1: 2500-scale map.

A concrete apron now extends across the low-lying stretch (London Clay capped by Head Brickearth) between Tankerton and Swalecliffe and control of erosion, helped by groynes, appears to be complete. The slope has been trimmed back to about 20° and bevelling was also carried out towards and past Stud Hill, where similar concreting was effected about 1960 after disastrous storm damage in 1946, 1953 and 1958 (see Lewis, 1962, pp. 126–127). About 450 m of land had been lost during 120 years, one of the consequences of building Hampton Pier. Again, contributing measures were the construction of groynes and of herring-bone drains feeding to primary drains discharging through the sea wall. Beyond the western end of the wall steel sheet piling was driven in order to check erosion around the wall end. It is recorded that just west of Hampton a sea wall 'built in 1932 had to be deepened in foundation in 1948 owing to foreshore scour' (So, 1967, p. 480).

From Hampton along the West Cliff of Herne Bay a substantial beach has been retained since the construction of Hampton Pier about 1864, advantageously for this stretch of coast; a low concrete wall, built in sections between about 1900 and 1928 also runs along the foot of the cliffs.

At the East Cliff of Herne Bay, after a wall was started in 1931, major constructional stabilising was carried out between 1937 and 1938 (Duvivier, 1940) but by 1956 tension cracks and tilting of the sea wall had developed. It is believed that the first sea defences were built about 1907, after an initial deep-seated rotational landslip. Subsequent renewals of movement, involving upheaval of London Clay on the foreshore and damage to the sea wall, had to be dealt with in 1935–36 and 1956–57 (Hutchinson, 1968a, p. 230). According to So (1967, p. 479) the 'trimmed and drained slopes in the eastern part of the Downs' were disturbed by slipping in the winter of 1951. When the existing sea wall protecting the East Cliff was re-faced and strengthened between 1961 and 1964 opportunity was taken to realign it, and the primary drains within the landslip area were deepened.

Beltinge Cliff, the scene of the spectacular Miramar slip of 1953, now offers no examples of eroding London Clay cliffs broadly in balance with weathering and occupied predominantly by mudslide corries; for effective coast stabilisation measures have destroyed them (Hutchinson, 1973, p. 225). Offshore may be discerned the skeletons of former wooden protective works (So, 1967, pp. 477–478) that did little to halt the considerable encroachment of the sea at that time. These were probably constructed around 1907. The present engineering constructions were at the Miramar slip preceded by a microfaunal study, from borehole samples, which served to locate precisely the rotational slip surface at a depth of 6.7 m below the subsidence soil-level seaward of the slip scarp. The evidence was obtained by comparing five ad hoc foraminiferal zones with their stratigraphy in the disturbed area (Hutchinson and Hughes, 1968). The zone nearest the London Clay base was also distinguished by the presence of a pyritised diatom referred to 'Coscinodiscus? sp.'.

The protection scheme has been completed eastward as far as Bishopstone Glen, and basically consists of a massive concrete wall (forming a promenade) backed by the usual oblique stone-filled drainage runs traversing the stabilised slip zone. In addition, foreshore dumping of bulldozed clay (London Clay) and rubble on a large scale has so far halted the tidal erosion regime, so that the cliffs (and much of the foreshore) west of the Glen are protected, but scour has increased to the east. There, where parts of the beach have been groyned, considerable shingle growth earlier took place (So, 1967, p.480).

Eastward, the cliffs of Oldhaven Beds, Woolwich Beds and Thanet Beds, locally capped by Head Brickearth, are defended only at Reculver, where protection was begun about 1809, by the Corporation of Trinity House, who also in due course preserved the twin towers of the ruined church as a landmark for sailors. There had been a phase of very strong erosion since 1805, so the construction of groynes was a matter of urgency and was at first seemingly ineffective enough, according to an account by Freeman in 1810 (see Ireland, 1828, pp.422–424, 445–446). Ireland's account also quotes an interesting stone inscription of 1819 (p.432) and comment that clearly shows an appreciation of the destructive effects of weathering and subsidence (Ireland, 1828, pp. 446–447). In later years, of course, massive concrete facing has been carefully maintained (Plate 11) and Ireland's prophecy of total collapse of the ancient fortress at Reculver negated; but not before further depredations (Gibb, 1862, p.332).

Index of landslips

Compiled from Hutchinson (1965a, b; see also Hutchinson, 1968a, pp. 227–232, 236–237). Index numbers and National Grid references as given by Hutchinson. Where the prefix letter K is followed by 'D' effective artificial sea defences (at 1965) are indicated; where followed by 'A' the entry refers to an abandoned cliff or inland slope. An asterisk denotes representation on the geological map. The original report (Hutchinson, 1965b) comprises Hutchinson's full documentation, with bibliography. Some notes on surface drainage have been included in the present list, also a few geological corrections.

References

BINGHAM, R. 1861. On the geology of the Island of Sheppey. Proc. Geol. Assoc., Vol. 1, pp. 92–106.

CAMDEN, W. 1586. Britannia. (London.)

DAVIS, A. G. 1936. The London Clay of Sheppey and the location of its fossils. Proc. Geol. Assoc., Vol. 47, pp. 328–345.

DAVIS, A. G. and ELLIOTT, G. F. 1951. Field meeting in Sheppey. Proc. Geol. Assoc., Vol. 62, p. 269.

DAVIS, A. G. and ELLIOTT, G. F. 1954. Field meeting in Sheppey. Proc. Geol. Assoc., Vol. 65, p. 383.

DEWEY, H., WOOLDRIDGE, S. W., CORNES, H. W. and BROWN, E. E. S. 1925. The geology of the Canterbury district. Proc. Geol. Assoc., Vol. 36, pp. 257–284.

D'OLIER, B. 1972. Subsidence and sea-level rise in the Thames Estuary. Philos. Trans. R. Soc. London, Series A, Vol. 272, pp. 121–130.

DOWKER, G. 1881. On the changes which have taken place in the coast and river valleys since the Roman occupation of Britain. East Kent Nat. Hist. Soc. Rep. 23.

DOWKER, G. 1900. Coast erosion. Read before the British Association, 1899. (Dover.)

DUNCOMBE, J. 1784. The history and antiquities of the two parishes of Reculver and Herne, in the county of Kent. Bibl. Topogr. Br., Vol. 1, Part 18, pp. 65–161.

DUVIVIER, J. 1940. Cliff-stabilization works in London Clay. J. Inst. Civ. Eng., Vol. 14, pp. 412–426.

GIBE, G. D. 1862. A visit to Reculver, in Kent. The Geologist, Vol. 5, pp. 330–333.

HOLMES, S. C. A. 1969. Written discussion on a paper taken as read: 1 April 1966 [SO, C.L. 1967]. Proc. Geol. Assoc., Vol. 80, pp. 269–270.

HOLMES, S. C. A. 1972. Geological applications of early large-scale cartography. Proc. Geol. Assoc., Vol. 83, pp. 121–138.

HOLMES, T. V. and WHITAKER, W. 1910. Excursion to Sheppey. Proc. Geol. Assoc., Vol. 21, pp. 486–488.

HUTCHINSON, J. N. 1965a. The stability of cliffs composed of soft rocks, with particular reference to the coasts of south-east England. Ph.D. Dissertation, University of Cambridge.

HUTCHINSON, J. N. 1965b. A survey of the coastal landslides of Kent. Building Research Station Note, No. EN. 35/65

HUTCHINSON, J. N. 1967. The free degradation of London Clay cliffs. Proc. Geotech. Conf. Oslo, Vol. 1, pp. 113–118.

HUTCHINSON, J. N. 1968a. Field meeting on the coastal landslides of Kent. Proc. Geol. Assoc., Vol. 79, pp. 227–237. - 1968b. Mass movement. Pp. 688–695 in The encyclopedia of geomorphology. FAIRBRIDGE, R. W. (Editor). (USA: Reinholt Publishers.)

HUTCHINSON, J. N. 1970. A coastal mudflow on the London Clay cliffs at Beltinge, North Kent. Geotechnique, Vol. 20, pp. 412–438.

HUTCHINSON, J. N. 1973. The response of London Clay cliffs to differing rates of toe erosion. Geol. Appl. & Idrogeol., Vol. 8, Part 1, pp. 221–239.

HUTCHINSON, J. N. and HUGHES, M. J. 1968. The application of micro-palaeontology to the location of a deep-seated slip surface in London Clay. Geotechnique, Vol. 18, pp. 508–510.

HUTCHINSON, J. N. and BHANDARI, R. K. 1971. Undrained loading, a fundamental mechanism of mudflows and other mass movements. Geotechnique, Vol. 21, pp. 353–358.

IRELAND, W. H. 1828. England's Topographer, or A new and complete history of the county of Kent. Vol. 1. (London.) JEssup, R. F. 1930. The archaeology of Kent. (London.)

LACEY, J. M. 1929. Littoral Drift along the north-east coast of Kent, and the erosion of the Beltinge Cliffs near Herne Bay. Selected Engineering Papers Inst. Civ. Eng. No. 70.

LEWIS, J. A. 1962. Contribution to discussion on a paper.[DUVIVIER, J. 1961.] Proc. Inst. Civ. Eng., Vol. 23, pp. 126–127.

LYELL, C. 1830. Principles of Geology. (1st Edition), Vol. 1, (London.)

LYELL, C. 1875. Principles of Geology. (12th Edition), Vol. 1, (London.) MAY, V. J. 1966. A preliminary study of recent coastal change and sea defences in south-east England. Southampton Res. Series in Geogr., Vol. 3, pp. 3–24.

McRAE, S. G. and BURNHAM, C. P. 1973. The rural landscape of Kent. Wye College (Univ. of London) for British Association, Canterbury Meeting.

MITCHELL, J. 1833. Observations on the cliff at Reculver in Kent. Proc. Geol. Soc. London, Vol. 2, [1838], p. 7.

PRENTICE, J. E. and others. 1968. Sediment transport in estuarine areas. Nature, London, Vol. 218, pp. 1207–1210.

RICHARDSON, W. 1834. A short notice of the coast section from Whitstable in Kent to the North Foreland in the same county. Proc. Geol. Soc. London, Vol. 2 [1838], pp. 78–79.

RICHARDSON, W. 1841. Observations on the locality of the Hyracotherium. Trans. Geol. Soc. London, Series 2, Vol. 6, pp. 211–214.

ROBINSON, A. H. W. 1953. The Storm Surge of 31st January–1st February, 1953. Geography, Vol. 38, pp. 134–141.

SO, C. L. 1967. Some coastal changes between Whitstable and Reculver, Kent. Proc. Geol. Assoc., Vol. 77 [for 1966], pp. 475–490.

SMITH, C. R. 1850. The Antiquities of Richborough, Reculver, and Lymne, in Kent. (London.)

STEERS, J. A. 1953. The Sea Coast. (London.) - 1964. The coastline of England and Wales. (2nd Edition). (Cambridge.)

WHEELER, W. H. 1902. The Sea-Coast. (London.)

WHITAKER, W. 1872. The geology of the London Basin. Mem. Geol. Surv., G.B.

WHITAKER, W. and DOWKER, G. 1885. Excursion to Canterbury, Reculvers, Pegwell Bay and Richborough. Proc. Geol. Assoc., Vol. 9, pp. 168–177.

WHITAKER, W. HOLMES, T. V. and SHRUBSOLE, W. H. 1898. Excursion to Sheppey. Proc. Geol. Assoc., Vol. 15, pp. 459–462.

WILLSON, B. 1902. Lost England: the story of our submerged coasts. (London.)

WORSFOLD, F. H. 1926. An examination of the contents of the brickearths and gravels of Tankerton Bay, Swalecliffe, Kent. Proc. Geol. Assoc., Vol. 37, pp. 326–339.

WORSFOLD, F. H. 1927. Observations on the provenance of the Thames Valley Pick, Swalecliffe, Kent. Proc. Prehist. Soc. East Anglia, Vol. 5 [for 1926], pp. 224–231.

WORSFOLD, F. H. 1955. Obit. Notice, by H.D., in Annual Report of the Council for 1954. Proc. Geol. Assoc., Vol. 66, pp. 165–166.

Chapter 11 Economic geology

General and historical

In the sixteenth century, pyrite occurring in the London Clay cliffs of the region was collected in order to make brimstone. Copperas (green vitriol) was also produced from pyrite and used for dyeing, tanning and for the manufacture of ink. Further details of the copperas trade are given on p. 1.

Gunpowder was manufactured in the Faversham area from the sixteenth century until the present century.

Salt workings are known from Seasalter Level, Graveney Marshes, at the old mouth of the River Wantsum and near Faversham. Saltpans are recorded in the area from before Domesday. They are associated today with mounds on the marshes up to 6 m high. An extensive explanation of these artificial mounds is to be found in pp. 96–99.

Whitaker (1827, p. 390) noted the working of pebbles from the Oldhaven Beds for the London, Chatham and Dover Railway, 'in the absence of better gravel'. He also mentioned the limited use of the iron ore at the base of the Oldhaven Beds for mending roads; 'for which however it is not well fitted'.

Septaria within the London Clay, particularly from the cliffs on the east of Sheppey, were formerly used in the manufacture of 'Roman cement'.

An early example of the exploitation of artesian water is described in the following quotation from W. H. Ireland (1829, p. 572): 'Mr Bunce, of Canterbury, who had drained the marshes and converted them into arable land, having found a bed of clay on the sea-shore, caused it to be perforated and, after some days' labour and anxious expectation, discovered, at the depth of seventy-two feet [21.9 m], the soil change from clay to sand, when he had the satisfaction of seeing an abundant flow of good fresh water, which after efficient means had been adopted, rose to the height of six feet [1.8 m] above the ground, and so continues at the present time. This source affords nine quarts of water in a minute, being more than sufficient for the purposes required by the population.' SCAH, RAE

Agriculture and soils

Details under this section are dealt with in Chapter 1.

Brickmaking

The Faversham region was famous for brickmaking from brickearth up until the middle of the present century when it became much restricted. The strata dug for bricks are grouped within the Head Brickearth previously described in details in Chapters 8 and 9. Brickearth has been dug in the Oare–Uplees area, although the main workings have been in the area around Faversham. At the Faversham Quay Brickfields the lowermost Thanet Beds were also used for brickmaking (Whitaker, 1872, p. 85). Weathered London Clay was originally only rarely used for making pipes and tiles and was dug at a shallow depth. Newman (1969, p. 23) gives a general account and description of brickmaking in Kent although no localities within this sheet are cited.

Today the only working brickworks lies to the west of Faversham. Here brickearth is scraped from a nearby shallow strip working and stockpiled. Any race is crushed or removed to prevent slaking and the brickearth is fed through a pug mill before being hand thrown into wooden templates. The bricks are dried for 3 to 4 days and then burnt in intermittent down-draught propane – fired kilns. Vitrification heat (950° to 1050°C) is reached in 3 to 4 days and the kiln is then left to 'soak' and cool for another seven days. The traditional hand-thrown Kentish sand-faced red bricks thus produced are not made anywhere else in Kent at present (1976).

Sand and gravel

Where they are accessible at outcrop, all the Lower London Tertiary Beds have been worked for sand at some time. Details of the pits are to be found in Chapters 5 and 6. Small excavations were particularly concentrated in the Hernhill area, where numerous pits worked sand from the Oldhaven and Woolwich beds, and at Shelford. Woolwich Beds and Oldhaven Beds are still extracted from the latter locality. The finer-grained cleaner sand of the Oldhaven Beds is used as a plastering sand and both formations are dug for building sand. More recently, sand from the Woolwich Beds has been mixed with 4-mm diameter gravel to be used as a sub-base in road construction.

Gravel for use as concrete aggregate has been extensively extracted from River Terraces and Head deposits abutting against the Lower London Tertiary Beds in the River Stour valley. Most of the gravel is now worked out although dredging of river gravels below the Alluvium in the Great Stour valley near Sturry and at Oare and Uplees has recently proved productive. Second Terrace gravels were formerly worked at Alluvium level in the Little Stour valley near Preston. Gravel has been extracted from many small pits in Head Gravel over the whole region and there are more extensive worked-out areas around Hoath. Recently excavations have started in Head Gravel around Highstead.

In 1975 the annual extraction of gravel reserves stood at 270 000 tonnes and the total yield of the reserves 1.5 million tonnes. There are few areas of resources which have not been explored and the estimated life of the reserves is quoted as 'medium term' around Faversham and only 'short term' around Hoath. Indeed, gravel dredged from the River Stour estuary in Suffolk is transported by sea into Whitstable.

Lime and whiting

Chalk was formerly quarried for agricultural lime and whiting in the Faversham district and at Sarre on the Isle of Thanet. Details of sections in the disused pits are given in Chapter 4. RAE

Coal<span data-type="footnote">We are indebted to Mr. A. R. L. Jones of the National Coal Board for this account.</span>

The Chislet Colliery shafts (TR 210619) were sunk between 1914 and 1918 and the Colliery, one of four in the Kent Coalfield, worked until 1969. The bulk of the total output of about 17 million tonnes was produced from the Kent No. 7 Seam (also known as Chislet No. 5 Seam) and was used for making cement, gas and electricity. The workings lie at depths of 330 to 550 m and cover an area of approximately18 sq. km., mainly to the south and east of the shafts since the seam outcrops under the Mesozoic cover approximately 1 km to the north.

The Kent No. 7 Seam at Chislet Colliery varied in thickness between 2.15 and 0.30 m and averaged 1.25 m. Variation was caused by sandstone/siltstone-filled channels in roof and floor and differential compaction around these. The coal has an ash content of around 5 per cent, sulphur 0.9 per cent, volatile matter 31 per cent, calorific value 36 500 KJ/Kg. (dry, mineral matter free basis). Two major faults cut the working striking NW–SE; these throw down to the south-west about 50 m each while the boundary of the workings on the south-west side is the line of another similar and parallel fault with a throw of 100 m. Little other faulting was encountered. Dips generally were to the southeast at 1 in 30.

Water supply

The higher ground of the North Downs lying to the south of this district is composed largely of permeable Chalk. There is no surface run-off and almost all rainfall which does not subsequently evaporate infiltrates into and recharges the Chalk. Consequently, with the exception of the Great Stour, no major streams enter the district. By contrast, the impermeable London Clay which covers the greater part of the district permits very little infiltration and gives rise to surface run-off as many small streams. The widespread alluvial material which occurs along the Wantsum, west of Whitstable and on the Isle of Sheppey, is drained by a largely artificial network.

The district lies within Hydrometric Area 40, which from 1 April 1974 has been administered by the Southern Water Authority. A comprehensive survey of the surface and groundwater resources of the county as well as of water supply and distribution within it, was prepared by the preceding Kent River Authority and published in 1970; reference to it should be made for detailed information. Other works include Downing (1956), Cooling and others (1964) and the Hydrogeological Map of the Chalk and Lower Greensand of Kent published by the Institute of Geological Sciences (1970).

Average annual rainfall within the district varies from less than 525 mm over parts of Sheppey to more than 650 mm over higher ground in the south. Over the Chalk recharge area of the North Downs rainfall exceeds 750 mm per annum (figures based on 1916–50 averages). Potential evapotranspiration over this coastal region of north Kent is variously measured and estimated to be between 500 and 575 mm per annum (Kent River Authority (1970); Ministry of Agriculture, Fisheries and Food (1967)); average actual evapotranspiration is probably about 10 per cent less than potential values, with soil moisture deficits rising above 200 mm in some years.

The general lack of large streams has led to a traditional use of groundwater for supply purposes, and there are no river intakes within the district. The Chalk is the principal aquifer and also the primary source of water supplies. None of the older formations are significant for water supply in this immediate area. The overlying Lower London Tertiaries consist of predominantly permeable materials, except for the clay in the lower part of the Thanet Beds which, over much of the district, separates the groundwater in the Chalk from that in the Lower London Tertiaries, although the two aquifers are in hydraulic continuity west of Faversham (Downing, 1956). The flow regime within the two is markedly different; in the Eocene aquifer flow is inter-granular, while that in the Chalk takes place almost entirely through fissures which may have been enlarged by solution processes. The Gault provides an impermeable base to the Chalk aquifer, and the basal clay in the Thanet Beds serves to confine the Chalk groundwater over much of the district. The groundwater in the Lower London Tertiaries is in turn locally confined by the impermeable London Clay.

The Chalk pressure surface rises to more than 15 m above OD along some parts of the southern boundary of the district. A ridge in the pressure surface trends north-east through Blean [TR 12 60] with gradients towards the Swale and Thames Estuary to the north and west, the Wantsum to the east and the Great Stour valley to the south-east (IGS, 1970). Locally, especially on the Isle of Sheppey, the pressure surface has been depressed by long-term abstraction, although minor fluctuations caused by recharge discharge relationships are superimposed. High yields can be obtained from the Chalk and Lower London Tertiaries and all wells yielding more than 50 megalitres per year derive their supplies from either or both of these formations. The highest recorded yield in the area is 63 litres per second for a drawdown of approximately 10 m from the shafts and headings of the Ford Pumping Station of the Mid Kent Water Company (273/10) [TR 204 656]. Good yields from the Chalk are dependent on the well intercepting major water-bearing fissures, so that large diameter boreholes, shafts and adits have been constructed. The density, distribution and aperture of fissures at any location depends inter alia on lithology, structure, topography and groundwater circulation. The principal joint system in Kent trends south-eastwards (Downing, 1956) but subordinate joints occur in other directions. Harder beds are frequently more heavily fissured than softer marly horizons. Hydraulic conductivity appears in general to be highest beneath valleys at outcrop and lowest in Chalk confined beneath the London Clay. This may be the result of variation in overburden pressure but is likely to be, at least in part, a result of the restricted groundwater circulation below the impermeable clay compared with that beneath the outcrop. This greater circulation has resulted in widening of fissures by solution.

Small lenses of sandy material occur locally within the London Clay from which supplies of a few litres per minute may be obtained, but the main hydrogeological significance of this formation is its role as an aquiclude.

The Claygate Beds above the London Clay are relatively impermeable. They also form an aquiclude, throwing out minor springs from the overlying Bagshot Beds on the Isle of Sheppey. The thickness and extent of the latter formation is so limited as to make it unimportant as an aquifer.

Limited supplies of water can be obtained locally from some of the alluvial, terrace and head gravels. In general, however, the volume of saturated material is insufficient to constitute a significant water resource, although average quantities in excess of one megalitre per day are abstracted from some quarry workings. Where the gravels are in hydraulic connection with a river an induced recharge scheme may offer possibilities for moderate supplies, provided low flows are not seriously affected (Kent River Authority, 1970).

Water from the Chalk is normally of satisfactory chemical quality for all purposes, although it is hard. As the Chalk and Lower London Tertiaries dip beneath the London Clay cover, the water becomes increasingly softened by cationic exchange.

Along much of the north Kent coast and on the Isle of Sheppey, over-abstraction has resulted in the lowering of water levels in the Chalk and Lower London Tertiaries below sea level, with consequent entry into the aquifers of saline water from the Thames Estuary. The chloride levels are above 100 parts per million over much of the district and some wells have been abandoned because of salinity, e.g. a well in Whitstable (273/110) [TR 111 667]. In a cottage well east of Herne Bay (273/33) [TR 227 693], a fresh-water lens approximately 10 m thick was detected in the Thanet Beds overlying denser brackish water (Cooling and others, 1964); this is a classic condition in coastal situations. MP

References

COOLING, C. M. and OTHERS. 1964. Records of wells in the area of the New Series one-inch (Geological) Faversham (273) and Ramsgate (274) sheets. Wat. Supply Pap. Geol. Surv. G.B., Well Cat. Ser.

DOWNING, R. A. 1956. The groundwater resources of the Chalk and Eocene of North Kent. Rep. Geol. Surv. WD/56/1. (Unpublished.)

INSTITUTE OF GEOLOGICAL SCIENCES. 1970. Hydrogeological map of the Chalk and Lower Greensand of Kent. Sheets 1 and 2. (London: Institute of Geological Sciences.)

IRELAND, W. H. 1829. England's Topographer, or A new and complete history of the county of Kent. Vol. II. (London.)

KENT RIVER AUTHORITY. 1970. First periodical survey of water resources. (Maidstone: Kent River Authority.)

MINISTRY OF AGRICULTURE, FISHERIES AND FOOD. 1967. Potential transpiration, Technical Bulletin No. 16. (London: HMSO.)

NEWMAN, J. 1969. The Buildings of England. North East and East Kent. (Harmondsworth: Penguin.)

PLUMPTRE, J. H. 1959. Underground waters of the Kent Coalfield. Trans. Inst. Min. Eng., Vol. 119, pp. 155–169.

WHITAKER, W. 1872. The geology of the London Basin. Mem. Geol. Surv. G.B.

Appendix 1 List of Geological Survey photographs

Copies of these photographs may be seen in the library of the Institute of Geological Sciences, Exhibition Road, South Kensington, London SW7 2DE. They all belong to Series A and may be supplied as black and white prints or lantern slides at a fixed tariff. Photographs by J. Rhodes

Index of fossils

See also Chapter 7. In compiling the following, qualifications of identification of tara (e.g. aff., cf., ?) have been disregarded.

• Acila bivirgata
• Actinocamax verus
• Actinoconchus planosulcatus
• Aechima (Bythocypris) siliqua
• Agathamminoides
• Agriolimax
• Agriolimax laevis
• Alethopteris decurrens
• Alethopteris lonchitica
• Antylus fiuviatilis
• Ammodiscus
• Anodonta
• Anodonta anatina
• Anodonta cygnea
• Annularia galioides
• Annularia radiata
• Anthracoceratites vanderbeckei
• Anthraconaia
• Anthraconaia cymbula
• Anthraconaia lanceolata
• Anthraconaia lenisulcata
• Anthraconaia obscura
• Anthraconaia pruvosti
• Anthraconaia pulchella
• Anthraconauta
• Anthraconauta phillipsii
• Anthraconauta tenuis
• Anthracosia
• Anthracosia aquilina
• Anthracosia aquilinoides
• Anthracosia ovum
• Anthracosia phrygiana
• Anthracosia pruvosti
• Anthracosia similis
• Aporrhais
• Araucaria
• Araucarites
• Arctica
• Arctica morrisi
• Arctica planata
• Arion
• Arion ater
• Astarte
• Astarte tenera
• Asterophyllites charaeformis
• Asterophyllites equisetiformis
• Asterophyllites grandis
• Asterotheca miltoni
• Athyris
• Atrypa desquamata
• Atrypa reticularis
• Aviculopecten
• Aviculopecten gentilis
• Balanus
• Balanus improvisus
• Beudanticeras
• Beudanticeras newtoni
• Beudanticeras sanctaecrucis
• Beyrichia maccoyana
• Bison
• 'Bithynia ventricosa'
• Bithynia tentaculata
• Bos
• Bos longifrons
• Bosprimigenius
• Bourgueticrinus
• Calamites
• Calamitescarinatus
• Calamites schutzeriformis
• Calamites suckowi
• Calamites undulatus
• Calamophloios
• Camarotoechia
• Camarotoechia nucula
• Candidula crayfordensis
• Candona torrosa
• Canis
• Cantitilia
• Capra
• Carbonicola
• Carbonicola bellula
• Carbonicola bipennis
• Carbonicola browni
• Carbonicola communis
• Carbonicola cristagalli
• Carbonicola 'declivis'
• Carbonicola martini
• Carbonicola polmontensis
• Carbonicola pseudorobusta
• Carbonita
• Carbonita humilis
• Carbonita salteriana
• Carbonita scalpellus
• Cardium
• Cardium edule
• Carpolithus
• Carychium minimum
• Cepaea nemoralis
• Cernuella virgata
• Cervus elaphus
• Chomataster
• Chonetes (Eodevonaria)
• Chonetes striatellus
• Cinnamomum
• Cochlicopa lubrica
• Cochlichnus kochi
• Coelodonta antiquitatis
• Columella columella
• Columella edentula
• Composita
• Composita ambigua
• Conulus
• Conulus albogalerus
• Conulus subrotundus (d'Orbigny) non Mantell
• Corbicula
• Corbicula fluminalis
• Corbula
• Corbula regulbiensis
• Cordaites borassifolizts
• Cordaites principalis
• Coscinodiscus
• Crateraster quinqueloba
• Crurithyris
• Cucullaea decussata
• Cupressinites
• Cypridina
• 'Cypridina phiiiipsi'
• Curvirimula
• Curvirimula candela
• Curvirimula subovata
• Cyprina
• Cyrtospirifer verneuili
• Donaldina
• Dorycordaites palmaeformis
• Dosiniopsis bellovacina
• Dosiniopsisbellovacina ensiformis
• Dosiniopsis orbicularis
• Douvilleiceras mammillatum
• Douvilleiceras monile
• Dunstania
• Earlandia
• Echinocorys scutata
• 'Elephas'
• Endothyra
• Entolium orbiculare
• Eochelys crassicostata
• Equus caballus
• Eremopteris artemisaefolia
• 'Estheria'
• Euphemites
• Euphemites anthracinus
• Fistuli pora
• Gari edvardsi
• Garwoodia gregaria
• Geisina
• Geisina arcuata
• Girvanella
• Globigerina
• Glycymeris terebratularis
• Gyrodes genti
• Hamites praegibbosus
• Helix
• Hemitrypa
• Hippopotamus amphibius
• Hollinella
• Hollinella bassleri
• Hoplites baylei
• Hoplites benettianus
• Hoplites dentatus
• Hoplites devisensis
• Hoplites (Isohoplites) eodentatus
• Hoplites paronai
• Hormotoma
• Hormotoma articulatum
• Hyaena spelaea
• Hydrobia radigueli
• Hydrobia ventrosa
• Hyolithes forbesi
• Hyracotherium leporinum
• Inoceramus concentricus
• Inoceramus salomoni
• Isselicrinus
• Isselicrinus subbasaltiformis
• Isurus mantelli
• Juglandicarya
• Koninckopora inflata
• Koskinotextularia
• Leionucula ovata forma derancei
• Lepidocarpon
• Lepidodendron
• Lepidodendron jaracyewski
• Lepidodendron ophiutus
• Lepidophloios acercsus
• Lepidophyllus
• Lepidostrobus
• Levipustula rimberti
• Limax
• Limax arborum
• Limopsis
• Limopsis aurita
• Lingula
• Lingula mytilloides
• Lingula strita
• Linoprotonia
• Littorina littorea
• Ludbrookia tenuicosta
• Lyelliceras lyelli
• Lyelliceras pseudolyelli
• Lymnaea truncatula
• Lymnaea palustris
• Lymnaea peregra
• Lymnaealagotis
• Magnolia
• Mammuthus primigenius
• Marginulina wetherellii
• Mariopteris
• Mariopterisdaviesi
• Mariopteris muricata
• Mariopteris nervosa
• Marsupites
• Mediocris mediocris
• Megaceros giganteus
• Megachonetes papilionaceus
• Metopaster
• Micraster
• Micraster coranguinum
• Monacha cartusiana
• Mya arenaria
• Myalina
• Mytilus edulis
• Naiadites
• Naiadites daviesi
• Naiadites flexuosus
• Naiadites obliquus
• Naiadites productus
• Neochonetes granulifer
• Neohibolites
• Neuropteris gigantea
• Neuropteris heterophvlla
• Neuropteris obliqua
• Neuropteris obliquus
• Neuropteris productus
• Neuropteris quadratus
• Neuropteris scheuchzeri
• Neuropteris tenuifolia
• Nipa
• Ophiomorpha
• Ophiomorpha nodosa
• Orbiculoidea
• Orbiculoidea nitida
• Orbiculoidea rugata
• Ortonella
• Ostrea bellovacina
• Ostreaedulis
• Otohoplites
• Ovis
• Pachythaerina
• Palaeolimnadiopsis pruvosti
• Palaeoloxodon antiquus
• Palaeoneilo
• Paludestrina deani
• Paludestrinaradigueli
• Paludestrina ventrosa
• Panopea
• Panopea granulata
• Panopea intermedia
• Panopea remensis
• Parallelodon
• Parallelodon reticularis
• Paraparchites
• Parastaffilla
• Pecten prestwichii
• Peringia ulnae
• Pholadomya
• Pholadomya konincki
• Pinnularia capillacea
• Pinus
• Pisidium
• Pisidium amnicum
• Pisidium astartoides
• Pisidium personatum
• Pisidium supinum
• Planolites ophthalmoides
• Planorbis carinatus
• Planorbis crista
• Planorbis laevis
• Planorbis leucostoma
• Planorbis spirorbis
• Platycarya
• Platyconcha
• Plicochonetes
• Polidevcia acuta
• Polidevcia attenuata
• Pomatias elegans
• Porosphaera globularis
• Potamopyrgus jenkinsi
• Praelacazella wetherelli
• Productus carbonarius
• Productus garwoodi
• Protanisoceras
• Protanisoceras moreanum
• Protohoplites (Hemisonneratia) puzosianus
• Pseudainusium contubernalis
• 'Pupa'
• Pupilla muscorum
• Quasiavonia aculeata
• Quasiendothyra nibelis
• Rangifer tarandus
• Renaultia rotundifolia
• Resatrix (Dosiniopsella) vibrayeana
• Reticularea
• Retispira tenuis
• Retispira undata
• Rhabdoderma
• Rhabdomeson
• Rhadinichthys
• Rhadinichthyslingula
• 'Rhinoceras'
• Rhinoceros hemitoechus
• Rhinodopsis
• Rhodea
• Samaropsis
• Scrobicularia
• Scrobicularia plana
• Serpuloides
• Serpuloides stubblefieldi
• Sequoia
• Sigillaria
• Sigillariaboblayi
• Sphaerium corneum
• Sphaerium rivicola
• Sphenophyllum
• Sphenophyllum cuneifolium
• Sphenophyllum myriophyllum
• Sphenophyllum saxifragaefolium
• Sphenopteris dilatata
• Spirorbis
• Stereocidaris
• Stigmaria ficoides
• Succinea
• Succinea arenaria
• Succinea oblonga
• Succinea pfeiffiri
• Succinea putris
• Succinea tessellata
• Symplocos
• Tentaculites tenuis
• Terebratulina
• Terebratulina striatula
• 'Teredo'
• Theba cantiana
• Thracia oblata
• Thyasira angulata
• Tomaculum
• Tornatellaea parisiensis
• Tornquistia diminuta
• Trigonoglossa
• Trigonoglossa nebraskensis
• Trochulus hispidus
• Tylocidaris clavigera
• Uintacrinus
• Uintacrinus socialis
• Union
• Union pictorum
• Ursus
• Vallonia excentrica
• Vallonia pulchella
• Valvata piscinalis
• Verneuilina
• Whitfieldella canalis
• Yoldia
• Zonitoides nitidus