| Computer Code: |
MRCG |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Ipswichian Stage (QI)
— Ipswichian Stage (QI) |
| Lithological Description: |
Boreholes indicate that the deposit can vary from sandy flint gravel to clayey, silty, pebbly sand. The deposit is commonly cross-bedded and shelly. Locally the gravels contain pebbles of limestone and ironstone in addition to flint. The fauna includes marine bivalves and gastropods, and mammalian bones have also been recorded. |
| Definition of Lower Boundary: |
The gravels rest unconformably on Oxford Clay Formation mudstones and elsewhere unconformably on chalk-rich till (uncertain whether this is of the Lowestoft Formation or possibly younger). At Town End, March, the gravels locally appear to be banked up against a low cliff or steep slope cut in the till. |
| Definition of Upper Boundary: |
The gravels typically crop out at the surface on 'raised islands'. Locally for example at Wimblington Common in the Ely district, the March Gravels are contiguous with the river terrace gravels. Seale (1975) noted that the two gravels are impossible to distinguish in some parts of the Ely district and that Baden-Powell's (1934) differentiation on the basis of their position relative to OD is unreliable. |
| Thickness: |
Up to about 5 m. |
| Geographical Limits: |
Margins of fenland in Cambridgeshire, Lincolnshire and Norfolk. |
| Parent Unit: |
Fenland Formation (FEND)
|
| Previous Name(s): |
March Gravel [Obsolete Name and Code: Use MRCG]
(-2946)
|
| Alternative Name(s): |
March Formation
|
| Stratotypes: |
| Type Area |
'islands' on the fen margin between Eye and Manea (Bowen, 1999). |
| Reference(s): |
| Horton, A. 1989. Geology of the Peterborough district. Memoir of the British Geological Survey, Sheet 158 (England & Wales). |
| Bridgland, D R, Keen, D H, and Davey, N D W. 1991. The Pleistocene sequence in the Peterborough District; possible correlation with the deep-sea oxygen isotope record. 209-212 in Central East Anglia and the Fen Basin; field guide. Lewis, S G, Whiteman, A, and Bridgland, R (editors). (Hampshire, United Kingdom: Quaternary Research Association.) |
| Seale, R S. 1975. Soils of the Ely district. Memoir of the Soil Survey of Great Britain. |
| Baden-Powell, D F W. 1934. On the marine gravels at March. Geological Magazine, Vol. 71, 193-219. |
| Gallois, R W. 1976. Ely project. 10-19, in IGS Boreholes 1975. Report of the Institute of Geological Sciences, No.76/10. |
| Keen, D H, Robinson, J E, West, R G, Lowry, F, Bridgland, D R and Davey, N D W. 1990. The Fauna and Flora of the March Gravels at Northam-Pit, Eye, Cambridgeshire, England. Geological Magazine, Vol.127, No.5, 453-465. |
| West, R G, Knudsen, K L, Penney, D N, Preece, R C and Robinson, J E. 1994. Paleontology and taphonomy of late Quaternary fossil assemblages at Somersham, Cambridgeshire, England and the problem of reworking. Journal of Quaternary Science, Vol.9, No.4, 357-366. |
| West, R G, Andrew, R, Knudsen, K L, Peglar, S M and Pettit, M E. 1995. Late Pleistocene deposits at Chatteris, March and Wimblington, Cambridgeshire, UK. Proceedings of the Geologists Association, Vol.106, 195-210. |
| Whitaker, W, Woodward, H B, Bennett, F J, Skertchly, S B J and Jukes-Browne, A J. 1891. The geology of parts of Cambridgeshire and of Suffolk (Ely,Mildenhall, Thetford). |
| Skertchly, S B J. 1877. The geology of Fenland. Memoir of the Gological Survey of Great Britain. |
| McMillan, A A, Hamblin, R J O, and Merritt, J W. 2011. A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) superficial deposits of Great Britain and the Isle of Man. British Geological Survey Research Report, RR/10/03. 343pp. |
| Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. |
| Gallois, R W. 1988. Geology of the country around Ely. Memoir of the British Geological Survey, Sheet 173 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E158
E159
E172
E173
|
