| Computer Code: |
BRG |
Preferred Map Code: |
notEntered |
| Status Code: |
Index Level |
| Age range: |
Pragian Age (DP)
— Emsian Age (DE) |
| Lithological Description: |
[Obsolete: use BRS] Red brown and purple sandstones with interbedded red siltstones and mudstones. |
| Definition of Lower Boundary: |
Drawn at the base of Brownstones where sandstones conformably rest upon sandstones of the Sewni Beds, the boundary being transitional with a colour change from green to red. |
| Definition of Upper Boundary: |
Drawn at the conformable upward passage of the Brownstones where they are unconformably overlain with slight discordance by the Plateau Beds. |
| Thickness: |
400 metres approx. |
| Geographical Limits: |
From Carmarthenshire and Pembroke across Wales to the Brecon Beacons and Welsh Borders. |
| 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 |
Brecon Beacons. |
| Reference(s): |
| Barclay, W J, Taylor, K, and Thomas, L P. 1988. Geology of the South Wales Coalfield. Part V. The country around Merthyr Tydfil. Third Edition. Memoir of the British Geological Survey, Sheet 231 (England and Wales). |
| Strahan, A, Gibson, W, and Cantrill, T C. 1904. The geology of the South Wales Coalfield, Part V. The country around Merthyr Tydfil. First Edition. Memoir of the Geological Survey of Great Britain. Sheet 231 (England and Wales). |
| Allen, J R L. 1977. Wales and the Welsh Borders. 40-54 in A correlation of Devonian rocks in the British Isles. House, M R et al. (editors). Geological Society, London, Special Report No. 7. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E249
E246
E234
E231
E250
|
