The BGS Lexicon of Named Rock Units — Result Details
Screes Gill Formation
| Computer Code: | SGI | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Ludlow Epoch (SU) — Ludlow Epoch (SU) | ||
| Lithological Description: | Thin, medium or thick beds of fine-grained sandstone grading up to mudstone, intercalated with thin-bedded siltstone-mudstone couplets, and laminated siltstone units. | ||
| Definition of Lower Boundary: | Below the first sandstone bed above the laminated siltstone of the Wray Castle Formation. | ||
| Definition of Upper Boundary: | Below a 70m thick siltstone-dominated unit, forming the basal division of the 'Undivided Coniston Group'. | ||
| Thickness: | About 280m in the type section. | ||
| Geographical Limits: | Unit, as defined, is recognised in the southern and central Howgill Fells (Sheet SD69). Correlation with lower part of Coniston Group in the northern Howgills is probable, but as yet unproven. | ||
| Parent Unit: | Coniston Group (CTG) | ||
| Previous Name(s): | Lower Coniston Grits [Obsolete Name and Code: Use SGI]
(-4878)
Lower Coniston Grits (part) [Obsolete Name and Code: Use SGI] (-3669) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Continuous dry stream section in Screes Gill and overlying crags. | ||
| Reference(s): | |||
| Kneller, B C, Scott R W, Soper N J, Johnson E W and Allen P M, 1994. Lithostratigraphy of the Windermere Supergroup, Northern England. Geological Journal, Vol. 29, 219-240. | |||
| Dakyns, J R, et al, 1891. The geology of the country around Mallerstang, with parts of Wensleydale, Swaledale and Arkendale. Memoir of the Geological Survey of England and Wales. | |||
| Rickards, R B, 1967. The Wenlock and Ludlow succession in the Howgill Fells (north-west Yorkshire and Westmorland). Quarterly Journal of the Geological Society, Vol.123, 215-251. | |||
| King, L M. 1992. A basin study of the early Palaeozoic Windermere Group, northwest England. Unpublished PhD thesis. University of Cambridge. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||