The BGS Lexicon of Named Rock Units — Result Details
Alston Formation
| Computer Code: | AG | Preferred Map Code: | AG |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Asbian Substage (CR) — Pendleian Substage (CE) | ||
| Lithological Description: | Bioclastic limestones, sandstones, mudstones, siltstones and rare coals typically in regular cyclothemic sequence. | ||
| Definition of Lower Boundary: | At top of Orton Formation: on Alston Block at base of a thin mudstone below Melmerby Scar Limestone; in Cumbria at conformable base of Sixth Limestone. | ||
| Definition of Upper Boundary: | Overlain conformably by rocks of the Stainmore Formation, the boundary been taken at the top of the Great Limestone Member. | ||
| Thickness: | c.340m | ||
| Geographical Limits: | British Geological Survey sheets 23, 24, 31. | ||
| Parent Unit: | Yoredale Group (YORE) | ||
| Previous Name(s): | Chief Limestone Group [Obsolete Name and Code: Use GSCL, AG]
(CHFL)
Upper Liddesdale Group (B) [Obsolete Name And Code: Use AG] (URL) Upper Liddesdale Group (A) [Obsolete Name And Code: Use AG] (ULDD) Gleaston Formation [Obsolete Name And Code: Use AG] (GTGP) Upper Liddesdale Group [Obsolete Name and Code: Use AG] (*190) Lower and Middle Limestone Groups [Obsolete Name and Code: Use AG] (-3791) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Partial Type Section | (Basal stratotype). Wildboar Scar: Arthurton and Wadge, 1981, pp.33-34. | ||
| Reference Section | Croglin Water sections: Arthurton and Wadge, 1981, pp.45 and 149. Top of Alston Group at NY 634 463. | ||
| Reference Section | The area between Bothel and Hesket Newmarket. | ||
| Reference(s): | |||
| Arthurton, R S, and Wadge, A J. 1981. Geology of the country around Penrith. Memoir for geological sheet 24. Institute of Geological Sciences, London, HMSO. | |||
| 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: | |||
| E031 E024 E023 E020 E018 E040 | |||