The BGS Lexicon of Named Rock Units — Result Details

Residual Deposits Group

Computer Code: RESID Preferred Map Code: Resi
Status Code: Full
Age range: Palaeogene Period (G) — Cromerian Stage (QC)
Lithological Description: Typical deposits include the Clay-with-flints Formation of southern Britain and the Buchan Gravels Formation of north-eastern Scotland. Clay-with-flints lithologies include reddish brown clay with large unworn flint cobbles, yellow fine-to-medium-grained sand, reddish brown clayey silt and sandy clay. Buchan Gravels lithologies include well-rounded gravel and cobbles of quartzite and flint with sand, silt and kaolinitic clay.
Definition of Lower Boundary: Irregular and unconformable contact with bedrock of Neogene age or older. In the case of Clay-with-flints, dissolution of underlying chalk has resulted in local development of pipes and hollows that are infilled with the residual deposits.
Definition of Upper Boundary: Generally the ground surface or overlain unconformably by Quaternary deposits.
Thickness: Clay-with-flints Formation: 2 - 10 m; Buchan Gravels Formation: greate than 25 m.
Geographical Limits: Southern Britain across the Chalk outcrop, northern England and north-eastern Scotland (Buchan) (for grid references see stratotype details).
Parent Unit: Great Britain Superficial Deposits Supergroup (GBG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  In Southern Britain, the type area of the Clay-with-Flints coincides with the outcrop of the Chalk [Cretaceous] over the North Downs, the Chiltern Hills and as far west as Somerset and Dorset. 
Type Area  In northeastern Scotland, the Buchan Gravels Formation crops out on the Buchan Ridge near Peterhead and at Windyhills, near Fyvie. The deposits rest with angular unconformity on the Moreseat Sandstone Formation or on Neoproterozoic rocks, both commonly deeply weathered. 
Reference(s):
McMillan, A A, Hamblin, R J O and Merritt, J W. 2004. An overview of the lithostratigraphical framework for Quaternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report. RR/04/04. 
Boulton, G S, Peacock, J D and Sutherland, D G. 2002. Quaternary. 409-430 in Trewin, N H [editor], Geology of Scotland. [4th edition]. [London: The Geological Society.] 
Dines, H G, Hollingworth, S E, Edwards, W, Buchan, S and Welch, F B A. 1940. The mapping of head deposits. Geological Magazine, Vol.77, 198-226. 
Ellison, R A, Woods, M A, Allen, D J, Forster, A, Pharaoh, T C and King, C. 2004. Geology of London. Memoir of the British Geological Survey, Sheets 256 (North London), 257 (Romford), 270 (South London), 271 (Dartford) (England and Wales). 
McMillan, A A and Powell, J H. 1999. The classification of artificial [man made] ground and natural superficial deposits. British Geological Survey Research Report, RR/99/04. 
Merritt, J W, Auton, C A, Connell, E R, Hall, A M and Peacock, J D. 2003. The Cainozoic geology and landscape evolution of northeast Scotland. Memoir of the British Geological Survey, Sheets 66E, 67, 76E, 77, 86E, 87W, 87E, 95, 96W, 96E and 97 (Scotland). 
Hall, A M and Connell, E R. 1991. The glacial deposits of Buchan, northeast Scotland. 129-136 in Ehlers, J, Gibbard, P L and Rose, J (editors), Glacial Deposits in Great Britain and Ireland. (Rotterdam: Balkema.) 
McMillan, A A and Merritt, J W, 1980. A reappraisal of the Tertiary deposits of Buchan, Grampian Region. Report of the Institute of Geological Sciences, No.80/1, p.18-25. 
Pepper, D M. 1973. A comparison of the "Argile a Silex" of Northern France with the "Clay-with-Flints" of Southern England. Proceedings of the Geologists' Association, Vol.84, 331-352. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable