| Computer Code: |
CLHS |
Preferred Map Code: |
ClHS |
| Status Code: |
Full |
| Age range: |
Arnsbergian Substage (CG)
— Arnsbergian Substage (CG) |
| Lithological Description: |
Siltstone, grey, sandy, micaceous, calcareous with rhythmic layers of fine-grained red-brown weathering, sandstone to 1cm; sporadic to common layers of sandy calcisiltite; rare to common Sanguinolites and bellerophontids. NOTE: This is a distinct/unique lithology within the Roeburndale Formation. The formation consists of delta slope siltstones with sandstones. There were previously three known marine bands with goniatite/bivalve faunas. The Close Hill Siltstone is a fourth new marine band. |
| Definition of Lower Boundary: |
Gradational to grey planty siltstones with common planty micaceous fine- to medium-grained sandstones over 10cm. (Delta slope deposits). |
| Definition of Upper Boundary: |
As lower boundary. |
| Thickness: |
c. 60m |
| Geographical Limits: |
Not known; probably extensive. Known from large area of Lancaster Fells, and probably extends throughout Lancaster Sheet. |
| Parent Unit: |
Roeburndale Member (RBL)
|
| Previous Name(s): |
Close Hill Siltstone Member [Obsolete Name and Code: Use CLHS]
(-4551)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Wray Borehole, 220-280m depth. |
| Reference Section |
Hamstone Gill. (top c.16m only well exposed). |
| Type Section |
Raghill Beck, near Close Hill. Bed of stream and meander scarps along Raghill Beck. |
| Reference(s): |
| Waters, C N, Waters, R A, Barclay, W J, and Davies, J R. 2009. Lithostratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/09/01. 184pp. |
| Brandon, A, Aitkenhead, N, Crofts, R G, Ellison, R A, Evans, D J, and Riley, N J. 1998. Geology of the country around Lancaster. Memoir of the British Geological Survey, Sheet 59 (England and Wales). |
| Slinger, F C, 1936. Millstone Grit and glacial geology of Caton Moor near Lancaster. Report of the British Association for the Advancement of Science, Blackpool 1936, 345. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E059
|
