The BGS Lexicon of Named Rock Units — Result Details

Honeycombed Sandstone Member

Computer Code: HNCS Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Asbian Substage (CR) — Asbian Substage (CR)
Lithological Description: Calcareous, locally conglomeratic, sandstone, with distinctive honeycomb weathering, locally in two tongues, separated by pale grey oolitic grainstone. Deposited as a transgressive shoreface sand/ooidal limestone.
Definition of Lower Boundary: Taken at sharp junction of the calcareous sandstone of the Member and the underlying dark bituminous skeletal/peloidal grainstone/packstone/wackestone of the Dowlais Limestone Formation.
Definition of Upper Boundary: Taken at the top of the upper tongue of calcareous sandstone of the Member, above which the pale grey ooid grainstones of the Penderyn Oolite Member enter.
Thickness: 4 to 12m
Geographical Limits: Northwest crop of the South Wales Coalfield [SN 94 14].
Parent Unit: Oxwich Head Limestone Formation (OHL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Penderyn Quarry [Cwar Aberamman], 250m east of Penderyn Church, Penderyn, Powys. Entire unit seen, comprising, lower tongue of sandstone [1.2m], intervening crinoidal/ooidal limestones [2m] and upper tongue of sandstone [1.2m]. Contacts with underlying Dowlais Limestone Formation and overlying Penderyn Limestone Member exposed. 
Robertson, T. 1932. Geology of the South Wales Coalfield, Part V, the country around Merthyr Tydfil, 2nd edition. Memoir of the Geological Survey of Great Britain, Sheet 231. 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used: