The BGS Lexicon of Named Rock Units — Result Details
Gleaston Formation [Obsolete: use AG]
| Computer Code: | GTGP | Preferred Map Code: | GlF |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Brigantian Substage (CX) — Brigantian Substage (CX) | ||
| Lithological Description: | [Obsolete: use AG] Variable sequence of thinly interbedded dark grey to black limestone, shaly mudstone and subordinate sandstone. Limestones richly fossiliferous in places with coral-brachiopod fauna. A bed containing abundent algal nodules 'Girvanella Nodular Bed' commonly occurs just above the base. | ||
| Definition of Lower Boundary: | Point where thickly bedded pale limestone of Urswick Limestone Formation passes up into the predominantly dark grey Gleaston Formation. | ||
| Definition of Upper Boundary: | Taken at base of the Cravenoceras leion Marine Band. | ||
| Thickness: | Variable 80-180m+ | ||
| Geographical Limits: | South Cumbria and North Lancashire, from Duddon estuary to Carnforth area. | ||
| Parent Unit: | none recorded or not applicable | ||
| Previous Name(s): | Gleaston Group [Obsolete Name and Code: Use GTGP]
(-1576)
Yoredales [Obsolete Name and Code: Use GTGP] (-1577) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | Gleaston Castle Farm Borehole (SD27SE/51) depths 124.27m to bottom at 165.36m. Borehole at c.44m OD, c.700m north-west of Gleaston Castle. Proved top and upper 41.09m of the formation. | ||
| Reference Section | Harbarrow No.1. Borehole SD27SE/37. Borehole, at c.52m OD, c.1000m north-west of Gleaston Castle, proved probably the whole formation, c.97m thick but not logged in detail. | ||
| Reference(s): | |||
| Dunham, K C and Rose, W C C. 1941. Geology of the iron-ore field of south Cumberland and Furness. Geological Survey of Great Britain, Wartime Pamphlet, No.16. | |||
| Lexique Stratigraphique International. 1971. Volume 1, Europe, Fascicule 3a, England, Wales and Scotland, Part 3a VII, Lower Carboniferous (Dinantian). | |||
| Rose, W C C. 1977. Geology and Hematite deposits of South Cumbria. Economic Memoir for 1:50,000 Sheet 58 and southern part of Sheet 48. Memoir of the geological Survey of Great Britain. | |||
| Dean, M T, Browne, M A E, Waters, C N and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report, RR/10/007. 165pp. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E059 E058 E048 | |||