| Computer Code: |
BGG |
Preferred Map Code: |
BGG |
| Status Code: |
Pending Upgrade |
| Age range: |
Llandovery Epoch (SL)
— Llandovery Epoch (SL) |
| Lithological Description: |
Dark grey mudstones and yellow to light grey laminated siltstones, fine-grained grey to yellow sandstones, which are massive, graded or parallel and/or ripple laminated. Sporadic graptolites. |
| Definition of Lower Boundary: |
Base unconformable on Ashgill sediments e.g. Maerdy Mudstone Formation. |
| Definition of Upper Boundary: |
Top succeeded by pale grey siltstones of the Bettws Mudstone Formation. |
| Thickness: |
To 500m |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
Not Applicable (-)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Corwen 120. |
| 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 Unpublished PhD Thesis, University of Cambridge.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
|
