The BGS Lexicon of Named Rock Units — Result Details

Cornubian Catchments Subgroup

Computer Code: CCAT Preferred Map Code: notEntered
Status Code: Full
Age range: Mid Pleistocene Epoch (QPM) — Holocene Epoch (QH)
Lithological Description: The Cornubian Catchments Subgroup encompasses all the fluvial, lacustrine and organic deposits of the rivers of Devon and Cornwall from the River Axe westwards. Floodplain alluvium comprises soft silts and clays, commonly with beds of peat and a basal bed of sand and gravel. River terrace deposits are largely sand and gravel. The gravels include a wide range of Palaeozoic and Mesozoic rocks, reflecting the rock types cropping out in the various catchments. Peat is a minor component, and minor marine deposits are included where they are intercalated in dominantly fluvial formations.
Definition of Lower Boundary: Unconformable on bedrock of Devonian to Cretaceous age.
Definition of Upper Boundary: Surface.
Thickness: Up to 22.5m recorded in the buried sub-drift valley of the 7th terrace of the Taw Valley Formation.
Geographical Limits: The catchments of the rivers of Devon and Cornwall from the River Axe westwards.
Parent Unit: Britannia Catchments Group (BCAT)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The area covered by the catchments of the rivers of Devon and cornwall from the River Axe westwards. 
Reference(s):
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