The BGS Lexicon of Named Rock Units — Result Details

Swansea Member [Obsolete Code: Use SW]

Computer Code: SWAM Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Asturian Substage (CAS) — Asturian Substage (CAS)
Lithological Description: Green-grey Pennant sandstones, seen as lithic arenites, with thin mudstone, siltstone and seatearth interbeds, and mainly thin coals.
Definition of Lower Boundary: At the base of the Golden (Swansea Three Feet or Graigola) seam (Woodland et al., 1957), where the coal rests on its underlying seatearth.
Definition of Upper Boundary: The base of the Wernffraith (Mynyddislwyn) Seam, (Woodland et al., 1957).
Thickness: From 274 m to 290 m thick.
Geographical Limits: The western part of the South Wales Coalfield, in the Swansea - Gorseinon - Gower area, and extending eastwards to the Margam - Tondu - Bettws area.
Parent Unit: Not Entered (?)
Previous Name(s): Swansea Beds (-4911)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
Woodland, A W, Evans, W B and Stephens, J V. 1957. Classification of the Coal Measures of South Wales with Special reference to the Upper Coal Measures. Bulletin of the Geological Survey of Great Britain, No. 13, 39-60. 
Waters, C N, Brown, M A E, Dean, M T and Powell, J H. In press. Lithostratigraphical framework for Carboniferous successions of Great Britain (Onshore). British Geological Survey Research Report, RR/05/06. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E247 E248