Geology
*Bedrock Geology Grovesend formation Gorseinon is built upon the Grovesend formation. Lithological characteristics are predominantly argillaceous, comprising mudstones and siltstones, with well developed coals; minor lithic ("Pennant") sandstones; locally developed red mudstones in the type area. Description of the lower boundary of this formation is that the base is placed at the base of the Swansea Four-Feet Coal of the Swansea district (equivalent of the Llantwit No.3 Seam in the Pontypridd district and the Mynyddislwyn Seam east of the Taff valley), where it overlies mudstone seatearth at the top of the predominantly arenaceous Swansea Member in the Swansea district and the similar Hughes Member in the east of the coalfield. It is a conformable boundary in the west, but is assumed to be an unconformable one in the east (Woodland et al., 1957; Squirrell and Downing, 1969; Barclay, 1989). Also taken at the base of the laterally correlatable Rudge Coal in the Radstack part of the Somerset Coalfield, the High Coal of the Bristol Coalfield and the Avonmouth No.1 Coal of the Severn Coal Basin. Description of the upper boundary is The Grovesend Formation is the youngest unit found in the South Wales and Forest of Dean coalfields. It is overlain unconformably by sandstones of the Sherwood Sandstone Group in the Newent Coalfield, by mudstones of the Mercia Mudstone Group in the Oxfordshire Coalfield and either the Sherwood Sandstone or Mercia Mudstone groups in the Bristol/Somerset Coalfields.References
External links
* http://www.angelfire.com/folk/gorseinon/ – Gorseinon History Archive Society Villages in Swansea {{Swansea-geo-stub