The BGS Lexicon of Named Rock Units — Result Details

Black Park Gravel Member

Computer Code: BPGR Preferred Map Code: notEntered
Status Code: Full
Age range: Anglian Stage (QA) — Anglian Stage (QA)
Lithological Description: Sand and gravel, with possible lenses of silt, clay or peat. [Generic description]. Horizontally stratified, matrix-supported gravel with thin tabular cross-bedded sand channels. Gravel assemblage is characterised by abundant angular flint (75-89%), sparse rounded flint (3-9%), sparse vein quartz (4-10%) and sparse quartzite (1-6%).
Definition of Lower Boundary: Rests unconformably on bedrock geology (London Clay on Sheet 256).
Definition of Upper Boundary: At surface.
Thickness: 1-6m, average 3m
Geographical Limits: Thames Valley and associated tributaries.
Parent Unit: Thames Valley Formation (TV)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Black Park Country Park, Slough. Stratotype: up to 4m of gravel and sand. Gibbard, 1985. 
Gibbard, P L, 1985. Pleistocene history of the Middle Thames Valley. (London: Cambridge University Press.) 
Strange, P J. 1992. A new nomenclature for the River Terrace Deposits of North London. British Geological Survey Technical Report, WA/92/52. 
Hare, F K, 1947. The geomorphology of a part of the Middle Thames. Proceedings of the Geologists' Association, Vol.58, 294-339. 
Gibbard, P L. 1979. Middle Pleistocene drainage in the Thames Valley. Geological Magazine, Vol.116, 35-44. 
Gibbard, P L. 1989. The geomorphology of part of the Middle Thames forty years on: a reappraisal of the work of F Kenneth Hare. Proceedings of the Geologists' Association, Vol.100, 481-503. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E254 E256 E257 E268