| 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): |
| 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. |
| 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). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E084
E075
E097
|
