The BGS Lexicon of Named Rock Units — Result Details

Ravenhead Rock

Computer Code: RHR Preferred Map Code: notEntered
Status Code: Full
Age range: Langsettian Substage (CA) — Langsettian Substage (CA)
Lithological Description: Sandstone and pebbly sandstone, part-reddened, medium-to-coarse-grained, micaceous, with well-defined soft hematic partings, and subordinate mudstone. A basal pebbly sandstone may be present, comprising clasts of mudstone and ironstone up to 2 feet in diameter.
Definition of Lower Boundary: The lower boundary is taken at a well-defined erosional surface. The base is taken at the base of the first sandstone unit above the Wigan 4 foot Coal, or where this is absent, the base of the first sandstone unit overlying the Wigan 5 foot Coal.
Definition of Upper Boundary: The upper boundary is taken at the base of a mudstone-dominated succession of the Pennine Lower Coal Measures Formation above the sandstone of the Ravenhead Rock.
Thickness: From 21m to 46m
Geographical Limits: Southern and western parts of the South Lancashire Coalfield.
Parent Unit: Pennine Lower Coal Measures Formation (PLCM)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Ellerbeck Borehole [SD51SE/10] (359030 414200), between 56 feet and 132 feet 3 inches below ground level. Both the top and base of formation are proved. Price et al., 1963. 
Reference Section  Lindsey Pit, Whelley, Wigan (359630 406920), which displays an exposure of basal pebbly sandstone. Jones et al,. 1938. 
Reference(s):
Price, D, Wright, W B, Jones, R C B, Tonks, L H and Whitehead, T H. 1963. Geology of the country around Preston. Memoir of the Geological Survey of Great Britain, Sheet 75 (England and Wales). 
Jones, R C B, Tonks, L H and Wright, W B, 1938. Wigan District. Memoir of the Geological Survey of Great Britain. England and Wales Sheet 84. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E084 E075 E097