| Computer Code: |
STPL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Arundian Substage (CJ)
— Holkerian Substage (CQ) |
| Lithological Description: |
Pale grey, thick-bedded skeletal and oolitic limestones; scattered cherts and silicified fossils; local dolomitisation. Dark grey, thinner-bedded limestones are common in the lower part. Pale grey oncolitic limestones and calcite mudstones are common in the uppermost part. Deposited in front barrier, barrier and back barrier settings. |
| Definition of Lower Boundary: |
Taken at the gradational boundary between the dark grey interbedded wackestones and mudstones of the underlying Pen-y-holt Limestone Formation and the pale grey thick-bedded skeletal and oolitic limestones of the Formation. Boundary taken at base of first oolitic limestone. |
| Definition of Upper Boundary: |
Taken at the outgoing of pale grey calcite mudstones of the Formation and the incoming of mottled [pseudobrecciated] skeletal packstones and palaeokarstic surfaces of the overlying Oxwich Head Limestone Formation. |
| Thickness: |
260m at type locality in southwest Pembrokeshire. |
| Geographical Limits: |
Castlemartin area [SR 95 98], southwest Pembrokeshire. Its relationship with the coeval Hunts Bay Oolite Subgroup to north and east is uncertain and needs further investigation. |
| Parent Unit: |
Pembroke Limestone Group (PEMB)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Variable accessible sea cliffs between Stackpole Quay and Barafundle Bay, Castlemartin, southwest Pembrokeshire. Entire unit seen and mainly comprises pale grey skeletal and oolitic limestones. Contacts with underlying Pen-y-holt Limestone Formation and overlying Oxwich Head Limestone Formation seen. |
| Reference(s): |
| Dixon, E E L. 1921. The Geology of the South Wales Coalfield, Part XIII , the country around Pembroke and Tenby, being an account of the region comprised in sheets 244 and 245. Memoir of the Geological Survey of Great Britain (HMSO). |
| 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: |
|
E244
E245
|
