| 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
|
| Stratotypes: |
| Type Area |
Wrexham, Sheet 121. |
| Reference(s): |
| 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 Unpublished PhD Thesis, University of Cambridge.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: |
|
E120
|
