The BGS Lexicon of Named Rock Units — Result Details
Brownstones Formation
| Computer Code: | BRS | Preferred Map Code: | Brs |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Lochkovian Age (DO) — Emsian Age (DE) | ||
| Lithological Description: | Red, brown and purple fluvial sandstones with red mudstone interbeds. | ||
| Definition of Lower Boundary: | (1) Where sandstones become dominant over mudstone in the underlying St Maughans Formation. (2) At colour change from predominantly green sandstone of the Senni Beds below, to red of the Brownstones. | ||
| Definition of Upper Boundary: | Where Upper Devonian or Lower Carboniferous beds overlie the Brownstones unconformably. | ||
| Thickness: | To 1200m | ||
| Geographical Limits: | South Wales and Welsh Borderlands, as far north as the Clee Hills. | ||
| Parent Unit: | Cosheston Subgroup (COB) | ||
| Previous Name(s): | Red Sandstone Group
(-671)
Monkey's Fold Formation (MFF) Brownstone Group [Obsolete Name And Code: See BRS] (BRG) Black Nore Sandstone Formation (BLNS) Brownstones [Obsolete Name and Code: Use BRS] (-2640) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | North face of Pen-y-fan. | ||
| Type Area | Black Mountains and Brecon Beacons. | ||
| Reference Section | Wilderness Quarry, Forest of Dean. | ||
| Reference(s): | |||
| Allen, J R L. 1974. The Devonian rocks of Wales and the Welsh Borderland. 47-84 in The Upper Palaeozoic and post-Palaeozoic rocks of Wales. Owen, T R (editor). (Cardiff: University of Wales Press.) | |||
| Allen, J R L, Halstead, L B, and Turner, S. 1968. Dittonian ostracoderm fauna from the Brownstones of Wilderness Quarry, Mitcheldean, Gloucestershire. Proceedings of the Geological Society, No. 1649, 141-153. | |||
| Symonds, W S, 1872. Records of the Rocks. [London.] | |||
| Welch, F B A and Trotter, F M. 1961. Geology of the country around Monmouth and Chepstow. Explanation of one-inch geological sheets 233 and 250. Memoir of the Geological Survey of Great Britain. | |||
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. | |||
| Allen, J R L. 1974. Source rocks of the Lower Old Red Sandstone; exotic pebbles from the Brownstones, Ross-on-Wye, Hereford and Worcester. Proceedings of the Geologists' Association, Vol. 85, 493-510. | |||
| 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). | |||
| Waters, R A and Lawrence, D J D. 1987. Geology of the South Wales Coalfield - Part III: the country around Cardiff. Memoir of the British Geological Survey, Sheet 263. (England and Wales). | |||
| 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. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E216 E263 E262 E234 E232 E230 E231 E233 E181 E182 E180 E197 E214 E215 E229 E212 E213 E246 | |||