| Computer Code: |
SES |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Late Devonian Epoch (DU)
— Tournaisian Age (CT) |
| Lithological Description: |
Interbedded grey quartzitic and red lithic sandstones, conglomerates, red mudstones and siltstones. |
| Definition of Lower Boundary: |
At sharp, unconformable junction where basal sandstones of the Skrinkle Sandstone Group rests on topmost conglomerate of the Ridgeway Conglomerate Formation. |
| Definition of Upper Boundary: |
Sharp junction at type locality where green sandstones are overlain by grey shales at the base of the Avon (Lower Limestone Shale) Group; gradational passage elsewhere in which red and green beds are replaced by grey beds. |
| Thickness: |
75 - 400 m; 91 m at type locality. |
| Geographical Limits: |
Pembroke peninsula, south-west Wales. |
| Parent Unit: |
Brecon Beacons Group (BRBE)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Sea cliff exposures, Skrinkle Haven, Pembrokeshire [SS 082 974]. Williams, 1971.
Reference section at sea cliff exposures West Angle Bay, Pembrokeshire, grid reference not given. Marshall, 1977. |
| 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). |
| Marshall, J D. 1978. West Angle Bay, Dyfed, pp. 99-101. In Friend, P F and Williams, B P J (eds.) A field guide to the Devonian of Scotland, the Welsh Borderland and South Wales. Palaeontological Association, London, 106pp. |
| Marshall, J D. 2000. Fault-bounded basin-fill: fluvial response to tectonic controls in the Skrinkle Sandstones of SW Pembrokeshire, Wales. In: Friend, P F and Williams, B P J. 2000 (eds). New Perspectives on the Old Red Sandstone. Special Publication, Geological Society, London, 180, 401-416. |
| Marshall, J D. 2000. Sedimentology of a Devonian fault-bounded braidplain and lacustrine fill in the lower part of the Skrinkle Sandstones, Dyfed, Wales. Sedimentology, 47, 325-42. |
| Williams, B P J. 1971. Sedimentary features of the Old Red Sandstone and Lower Limestone Shales of south Pembrokeshire, south of the Ritec Fault. In Bassett, D. A. and Bassett, M. G. Geological Excursions in South Wales and the Forest of Dean. The Geologists’ Association, South Wales Group, Cardiff, pp. 222-239. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E245
E244
|
