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
Stratotypes:
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. 
Reference(s):
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:
E231