The BGS Lexicon of Named Rock Units — Result Details

Glamorgan Glacigenic Formation

Computer Code: GLGL Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Stony clay diamicton (till) and sand and gravel with clasts predominantly of Carboniferous rocks (sandstone, siltstone, mudstone)derived from the South Wales Coalfield. Brown and purplish red clays, silts and sands with small pebbles are developed locally.
Definition of Lower Boundary: Unconformable on bedrock of the South Wales Coal Measures and Warwickshire groups
Definition of Upper Boundary: Ground surface or overlain by fluvial deposits (Severn and Avon Catchments Subgroup) or head
Thickness: Up to 30 m (Woodland and Evans, 1968)
Geographical Limits: Rhondda Fawr, Maesteg, Pontypridd, Pencoed districts (South Wales Coalfield)
Parent Unit: Wales Glacigenic Subgroup (WALES)
Previous Name(s): Glamorgan Drift (-1561)
Alternative Name(s): none recorded or not applicable
Type Area  Valley of Rhondda Fawr Bowen, 1999 
Woodland, A W and Evans, W B. 1964. The Geology of the South Wales Coalfield, part IV the Country around Pontypridd and Maesteg. Memoirs of the Geological Survey of Great Britain, One-Inch Geological Sheet 248 (England and Wales). 
David, J W E, 1883. On the evidence of glacial action in south Brecknockshire and east Glamorgan. Quarterley Journal of the Geological Society, London, Vol.39. 39-54. 
Bowen, D Q. 2005. South Wales. In Lewis, C A and Richards, A E (editors), The glaciations of Wales and adjacent areas. (Logaston Press.) 
Wilson, D, Davies, J R, Fletcher, C J N, and Smith, M. 1990. The Geology of the South Wales Coalfield, part VI the Country around Bridgend. Memoir of the British Geological Survey, 1:50 000 Geological Sheets 261 and 262 (England and Wales). 
Bowen, D Q, 1999. Wales. Chapter 7 in Bowen, D Q (Editor), A revised correlation of Quaternary deposits in the British Isles. Geological Society of London Special Report, No.23. 
Bowen, D Q. 1970. South-east and central Wales. 197-228 in Lewis, C A (editor) The glaciations of Wales and adjoining areas. (London: Longman.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable