The BGS Lexicon of Named Rock Units — Result Details

Trent-Witham Catchments Subgroup

Computer Code: TRWCA Preferred Map Code: notEntered
Status Code: Full
Age range: Anglian Stage (QA) — Holocene Epoch (QH)
Lithological Description: The Trent-Witham Catchments Subgroup comprises a suite of fluvial, lacustrine, mass movement (head), periglacial and organic (peat) deposits. The subgroup includes the alluvium and river terrace deposits of the Trent and Witham valleys and pre-diversionary valleys (Trent Valley Formation), the Soar valley (Soar Valley Formation) and the Bain valley (Bain Valley Formation) and their respective tributaries, including the Derwent (Derbyshire), Dove and Devon. The fluvial deposits contain clasts derived from rocks cropping out in the Midlands of England (mainly Triassic "Bunter" sandstone, ironstone and chert, Carboniferous sandstone, Lias siltstone, limestone and ironstone).
Definition of Lower Boundary: Unconformable contact with units of the Albion Glacigenic Group and bedrock.
Definition of Upper Boundary: Generally the ground surface, but units of this group interfinger locally with units of the Great Britain Coastal Deposits Group.
Thickness: Generally less than 5m. Individual terrace deposits up to 9m thick.
Geographical Limits: The catchments of the valleys of the rivers Trent and Witham, Soar and Bain and their tributaries south and east of the Peak District and including Lincolnshire.
Parent Unit: Britannia Catchments Group (BCAT)
Previous Name(s): Trent Catchments Subgroup (-3733)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Deposits of the catchments of the valleys of the rivers Trent and Witham, Soar, Bain and their tributaries south and east of the Peak District including Lincolnshire. See also stratotypes of constituent formations. 
Reference(s):
Maddy, D. 1999. English Midlands Chapter 3 in Bowen, D Q (Editor), A revised correlation of the Quaternary deposits in the British Isles. Geological Society Special Report, No.23. 
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