| Computer Code: |
SAM |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Lochkovian Age (DO)
— Pragian Age (DP) |
| Lithological Description: |
[Obsolete; use FWW] Red or green siltstones (marls). Red, sometimes nodular mudstones, very fine- to fine-grained, bright green or purple sandstones and intra-formational conglomerates. (Sandstone and Marl Group = division of Red Marls). |
| Definition of Lower Boundary: |
Drawn at base of feldspathic grits and breccias and grey shales of the Sandstone and Marl Group where they rest conformably on purple marl of the Lower Marl Group. |
| Definition of Upper Boundary: |
Drawn at conformable upward passage from red marls of the Sandstone and Marl Group to siltstones of the Upper Marl Group. |
| Thickness: |
Approx. 200 metres - 275 metres. |
| Geographical Limits: |
Southwest Wales. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
South Pembrokeshire, Dyfed, Wales. |
| 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). |
| House, M R, Richardson, J B, Chaloner, W G, Allen, J R L, Holland, C H and Westoll, T S. 1977. A Correlation of Devonian rocks of the British Isles. Geological Society of London, Special Report No.8, Scottish Academic Press, Edinburgh. |
| King, W W. 1934. The Downtonian and Dittonian strata of Great Britain and north-western Europe. Quarterly Journal of the Geological Society of London, Vol. 90, 526-570. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
