| Computer Code: |
POSH |
Preferred Map Code: |
notEntered |
| Status Code: |
Pending Upgrade |
| Age range: |
Harnagian Substage (OG)
— Soudleyan Substage (OY) |
| Lithological Description: |
Black pyritous mudstones overlie a basal conglomerate and are succeeded by buff weathering, greenish grey, silty micaceous mudstones and siltstones. |
| Definition of Lower Boundary: |
Basal conglomerate overlies Uriconian Group (Precambrian) volcanic rocks with marked unconformity. |
| Definition of Upper Boundary: |
Not seen. |
| Thickness: |
At least 50m |
| Geographical Limits: |
Not recorded. |
| Parent Unit: |
Not Applicable (-)
|
| Previous Name(s): |
Pontesford Shales [Obsolete Name and Code: Use POSH]
(-4848)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Dean, W T, and Dineley, D L. 1961. The Ordovician and associated Pre-Cambrian rocks of the Pontesford District, Shropshire. Geological Magazine, Vol. 98, 367-376. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
