The BGS Lexicon of Named Rock Units — Result Details

Petrockstow River Terrace Deposits, 1 Member [Duplicate Code: Use PET1]

Computer Code: PETR1 Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Pleistocene Epoch (QP) — Pleistocene Epoch (QP)
Lithological Description: The deposits of the first terrace are largely gravels of Carboniferous sandstone with scattered flints, with thin seams of clayey sand and sandy clay, 1.5 to 7m thick. The clasts are up to 20mm in diameter, increasing to 130mm at the base.
Definition of Lower Boundary: Unconformable on bedrock of Palaeogene and Late Carboniferous age.
Definition of Upper Boundary: At the land surface.
Thickness: To about 7m
Geographical Limits: The Petrockstow Basin, Devonshire.
Parent Unit: Petrockstow Valley Formation (PETRO)
Previous Name(s): River Terrace Deposits, 1 (Petrockstow) (-449)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The valley of the Petrockstow Basin. Freshney et al., 1979. 
Reference(s):
Freshney, E C, Beer, K E and Wright, J E. 1979. Geology of the country around Chumleigh. Memoir of the Geological Survey of Great Britain, Sheet 309 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E308 E309