| Computer Code: |
POLG |
Preferred Map Code: |
Polg |
| Status Code: |
Full |
| Age range: |
Early Devonian Epoch (DL)
— Early Devonian Epoch (DL) |
| Lithological Description: |
A dark grey, slatey cleaved mudstone, which has a marked absence of coarser lithologies, and showing low grade (anchizone) regional metamorphism. |
| Definition of Lower Boundary: |
Faulted against the Portscatho Formation, comprising predominantly turbiditic sandstone beds. |
| Definition of Upper Boundary: |
Faulted against the Hallane Formation, seen as a mudstone with siltstone and limestone. |
| Thickness: |
Unknown, as obscured by complex folding, but probably at least 500m. |
| Geographical Limits: |
Mevagissey Sheet 353 (England and Wales), but is known to extend northwards onto the Bodmin and St. Austell Sheet (347), for which no modern mapping is available. |
| Parent Unit: |
Meadfoot Group (MDT)
|
| Previous Name(s): |
Meadfoot Beds
(-76)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Coastal section between Polrudden Cove and Polgwyn Beach. |
| Reference(s): |
| Reid, C, 1907. Geology of the country around Mevagissey. Memoir of the Geological Survey of Great Britain. (London: HMSO.) |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E353
E354
|
