The BGS Lexicon of Named Rock Units — Result Details
Calder Sandstone Formation [Obsolete: use WLSF]
| Computer Code: | CSA | Preferred Map Code: | CSa |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Early Triassic Epoch (TE) — Early Triassic Epoch (TE) | ||
| Lithological Description: | [Obsolete: use WLSF] Red brown, medium to coarse, generally poorly sorted well rounded sandstone, cross bedded. Onshore aeolian sandstones are dominant: offshore fluvial sandstones are dominant. | ||
| Definition of Lower Boundary: | The lower boundary on the underlying St Bees Sandstone Formation is sharp and is taken at the upward change to typical aeolian sandstones from typical fluvial sandstones, which are finer grained and better cemented. Geophysically the boundary is sharp, marked by an increase in sonic interval transit time and an increase in gamma-ray values. | ||
| Definition of Upper Boundary: | Taken at the top of a thick (40-50m) fluvial sandstone unit that is well cemented and overlain by coarser, less well cemented aeolian sandstones (Ormskirk Sandstone Formation). The top is marked by a rapid decrease in gamma-ray values and an increase in sonic interval transit times. | ||
| Thickness: | 469-529 m in Sellafield boreholes. | ||
| Geographical Limits: | West Cumbrian Coast, between Sellafield and Drigg/Ravenglass | ||
| Parent Unit: | none recorded or not applicable | ||
| Previous Name(s): | "Upper" St Bees Sandstone [Obsolete Name and Code: Use CSA]
(-2125)
Part of St Bees Sandstone [Obsolete Name and Code: Use CSA] (-4571) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | (Top part) Sellafield Borehole 13B, BGS Registered No NY00SW/42, 176.42 - 295.70 m. | ||
| Partial Type Section | (Bottom part) Sellafield borehole 10B, BGS Registered No. NY00SW/40, 22.22 - 190.35 m. | ||
| Reference Section | River Calder valley between Calder Bridge and Sellafield Power Station. | ||
| Reference(s): | |||
| Jackson, D I, Mulholland, P, Jones, S M and Warrington, G, 1987. The geological framework of the East Irish Sea Basin. 191-203 in Brooks J and Glennie, K (editors), Petroleum Geology of North West Europe. [Graham and Trotman.] | |||
| Barnes, R P, Ambrose, K, Holliday, D W, and Jones N S. 1994. Lithostratigraphical subdivision of the Triassic Sherwood Sandstone Group in west Cumbria. Proceedings of the Yorkshire Geological Society, Vol. 50, 51-60. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E047 E037 | |||