The BGS Lexicon of Named Rock Units — Result Details

Corwen Grit Member

Computer Code: CWG Preferred Map Code: CWG
Status Code: Pending Upgrade
Age range: Hirnantian Age (OH) — Hirnantian Age (OH)
Lithological Description: Coarse grained sandstones, thin siltstones and a locally developed limestone member at the base. Richly fossiliferous.
Definition of Lower Boundary: Base overlies calcareous sandstones of the Dolhir Formation.
Definition of Upper Boundary: Top is succeeded by pale grey siltstones with some interbedded thin sandstones of the Fron Frys Formation.
Thickness: 70 metres. Lateral variations, 21 metres - 70 metres.
Geographical Limits: Not defined.
Parent Unit: Dolhir Formation (DO)
Previous Name(s): Corwen Grit (-832)
Alternative Name(s): none recorded or not applicable
Type Area  Wrexham, Sheet 121. 
Campbell, S D G. 1983. The geology of an area between Bala and Betws-y-Coed, North Wales. Unpublished PhD Thesis, University of Cambridge. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: