| Computer Code: |
PBK |
Preferred Map Code: |
PBK |
| Status Code: |
Full |
| Age range: |
Holkerian Substage (CQ)
— Asbian Substage (CR) |
| Lithological Description: |
Predominantly limestone but with interbedded sandstone and possibly mudstone. Limestones not only include pale grey biosparites etc, as in Knipe Scar Limestone, but also dark grey, platy beds. |
| Definition of Lower Boundary: |
Where medium to dark grey, medium- and coarse-grained limestones and shaly limestones of the Potts Beck Limestone overlie pale, grey-brown, flaggy, fossiliferous limestone of the Ashgill Limestone. |
| Definition of Upper Boundary: |
Where pale grey limestone and dark grey limestone and sandstone of the Potts Beck Limestone is overlain by pale grey, scar-forming limestone (mostly thick-bedded biosparites and biopelsparites commonly pseudobrecciated) of the Knipe Scar Limestone. |
| Thickness: |
70 metre. (Thins slightly westward to c.60m north of Orton). |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
Great Scar Limestone Group (GSCL)
|
| Previous Name(s): |
Potts Beck Limestone [Obsolete Name and Code: Use PBK]
(-1753)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Base at Little Asby Scar on north side of Potts Valley, near Newbiggin-on-Lune, Cumbria. (Sheet 40). |
| Type Section |
Great Kinmond. |
| Reference(s): |
| George, T N, Johnson, G A L, Mitchell, M, Prentice, J E, Ramsbottam, W H C, Sevastopulo, G D and Wilson, R B. 1976. A correlation of the Dinantian rocks of the British Isles. Special Report of the Geological Society of London, No 7. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E040
|
