The BGS Lexicon of Named Rock Units — Result Details

Well Hill Gravel Formation

Computer Code: WHGR Preferred Map Code: symb
Status Code: Full
Age range: Early Pleistocene Epoch (QPE) — Early Pleistocene Epoch (QPE)
Lithological Description: Gravel and sandy gravel; sub-angular, partly water-rolled flints up to 0.3m across, Lower Greensand cherts up to 10%. Tertiary pebbles, many decomposed brown flints; matrix of coarse sand, mostly quartzose, some flint; rare lenses of clay.
Definition of Lower Boundary: Rests unconformably on bedrock: Lambeth Group (Woolwich and Reading Beds).
Definition of Upper Boundary: Surface.
Thickness: 2 to 4m
Geographical Limits: Geographically isolated from other superficial deposits, at OD 155-167m, capping a hill at Well Hill, Kent.
Parent Unit: Crag Group (CRAG)
Previous Name(s): Plateau Gravel (PLG)
Well Hill Gravel (-4970)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Capping hill top alongside Well Hill Road north for 700m from main east-west road (Rock Hill) in Well Hill village. Dewey et al, 1924. 
Reference(s):
Dewey, H, Bromehead, C E N, Chatwin, C P and Dines, H G. 1924. The geology of the country around Dartford. Memoir of the Geological Survey, Sheet 271 (England and Wales). 
Peake, D S. 1982. The ground upon which Croydon was built. A reappraisal of the Pleistocene history of the River Wandle and its basin. Proceedings of the Croydon Natural History and Scientific Society, Vol.17, 89-116. 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E271