The BGS Lexicon of Named Rock Units — Result Details
Down Cliff Clay Member
| Computer Code: | DCC | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Toarcian Age (JT) — Toarcian Age (JT) | ||
| Lithological Description: | Grey, calcareous, bioturbated silicate mudstones, locally very finely sandy and micaceous, which generally increases upwards. In upper part, beds up to 0.5m thick of pale grey calcareous very fine-grained silicate-sandstone or finely sandy limestone occur. Fauna includes ammonites. | ||
| Definition of Lower Boundary: | Base probably a non-sequence: sandy mudstone resting sharply on fossiliferous fine limestones of the Beacon Limestone Formation. | ||
| Definition of Upper Boundary: | Top is marked by the change up from sandy mudstone to sands or sandstones of the undivided Bridport Sand Formation. | ||
| Thickness: | Dorset coast: 10 to 21m. Inland Dorset: 0 to 121m (Bristow et al., 1995). East Somerset up to 12m. | ||
| Geographical Limits: | Dorset from Bridport to Shaftsbury; Shepton Mallet area of east Somerset. | ||
| Parent Unit: | Bridport Sand Formation (BDS) | ||
| Previous Name(s): | Down Cliff Clay [Obsolete Name and Code: Use DCC]
(-204)
Down Cliffs Clay [Obsolete Name and Code: Use DCC] (-1488) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Coastal cliffs from Ridge (Down) Cliff to Thorncombe Beacon, Bridport, Dorset. Fully exposed but poorly accessible in upper part of cliffs. Hesselbo and Jenkyns, 1995, fig.16. | ||
| Reference Section | East Cliff, West Bay, Dorset. Uppermost 4m visible and accessible. Hesselbo and Jenkyns, 1995. p.123, fig.16. | ||
| Reference(s): | |||
| Cox, B M, Sumbler, M G, and Ivimey-Cook, H C. 1999. A Formational framework for the Lower Jurassic of England and Wales (Onshore Area). British Geological Survey Research Report No. RR/99/01. | |||
| Wilson, V, Welch, F B A, Robbie, J A, and Green, G W. 1958. Geology of the country around Bridport and Yeovil. Memoir of the Geological Survey of Great Britain, Sheets 327 and 312 (England and Wales). | |||
| Callomon, J H and Cope, J C W. 1995. The Jurassic geology of Dorset. 51-103 in Taylor, P D (Editor), Field Geology of the British Jurassic. (Bath: The Geological Society.) | |||
| Buckman, S S. 1922. Jurassic Chronology: II - Preliminary studies. Certain Jurassic strata near Eypesmouth (Dorset): the Junction-Bed of Watton Cliff and associated rocks. Quarterly Journal of the Geological Society of London, Vol. 78, 378-436. | |||
| Hesselbo, S P and Jenkyns, H C A, 1995. A comparison of the Hettangian to Bajocian successions of Dorset and Yorkshire. 105-150 in Taylor, P D (Editor). Field geology of the British Jurassic (London Geological Society). | |||
| Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, Ivimey-Cook, H C, and Taylor, R T. 1995. Geology of the country around Shaftesbury. Memoir of the British Geological Survey, Sheet 313 (England and Wales). | |||
| Arkell, W J. 1933. The Jurassic System in Great Britain (Oxford: Clarendon Press.) | |||
| Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, and Woods, M A. 1999. The Wincanton district - a concise account of the geology. Memoir of the British Geological Survey, Sheet 297 (England and Wales). | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E327 E341 E342 E343 E280 E297 | |||