| Computer Code: |
SH |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Arnsbergian Substage (CG)
— Yeadonian Substage (CY) |
| Lithological Description: |
[Obsolete: use MG]
Dark grey, blue and black shales with bands of grit, sandstone and quartzite. The sandstones are lenticular. |
| Definition of Lower Boundary: |
Drawn at base of sandstone of the shale group where it rests conformably on shale of the basal grit. |
| Definition of Upper Boundary: |
Drawn at conformable upward passage from dark shales of the Shale Group to brown, green and yellow sandstones and quartzites of the Farewell Rock. |
| Thickness: |
About 100 metres thick. |
| Geographical Limits: |
North Crop of South Wales Coalfield. |
| 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 |
North crop of South Wales Coalfield, Wales. From Nolton, near Haverfordwest, Dyfed, to the River Clydach, near Abergavenny. |
| Reference(s): |
| George, T N. 1970. British Regional Geology, South Wales, Third Edition. British Geological Survey. |
| Barclay, W J, Jackson, D I, Mitchell, M, Owen, B, Riley, N J, White, D E, Strong, G E, and Monkhouse, R A. 1989. Geology of the South Wales Coalfield, Part II, the country around Abergavenny. Memoir of the British Geological Survey. |
| Jones, D G, 1974. The Namurian in South Wales. "In" Owen, T R. The Upper Palaeozoic and past-Palaeozoic rocks of Wales. |
| Robertson, T, 1927. South Wales Coalfield, part 2. Abergavenny, 2nd Edition.Memoirs of the Geological Survey of Great Britain, p.42. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E232
|
