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: Includes remanie deposits formed by weathering and solifluction of original Palaeogene bedrock and Neogene to Early Quaternary superficial deposits. Typical deposits include the Clay-with-Flints of southern Britain and the Buchan Gravels Formation of northeastern Scotland. For the latter see stratotypes of constituent members: Buchan Ridge Gravel, Windy Hills Gravel. 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 deposit.
Definition of Upper Boundary: Generally at the ground surface or overlain unconformably by Quaternary deposits.
Thickness: Clay-with-Flints: 2 to 10m; Buchan Gravels Formation: 25m+
Geographical Limits: Southern Britain across the Chalk outcrop and northeastern 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 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. 
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. 
Reference(s):
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). 
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.) 
Merritt, J W, Auton, C A, Connell, E R, Hall, A M and Peacock, J D. 2003. The Cainozoic geology and landscape evolution of north-east Scotland. Memoir of the British Geological Survey, Sheets 66E, 67, 76E, 77, 86E, 87W, 87E, 95, 96W, 96E and 97 (Scotland) 
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.] 
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. 
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. 
McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable