The BGS Lexicon of Named Rock Units — Result Details

Barncroft Beck Beds

Computer Code: BACB Preferred Map Code: BacB
Status Code: Full
Age range: Arnsbergian Substage (CG) — Arnsbergian Substage (CG)
Lithological Description: Variably interbedded sandy micaceous planty siltstones and fine-grained sandstones.
Definition of Lower Boundary: Sharp between fossiliferous fissile clayey blue-grey mudstones with limestone nodules and thin sideritic lenses of Caton Shale below and siltstones with sandstones of the Barncroft Beck Beds above. Coincident with the base of the Claughton Member.
Definition of Upper Boundary: Base of coarse-grained Nottage Crag Grit above siltstones and fine-grained sandstones of the Barncroft Beck Beds.
Thickness: Approximately 85m
Geographical Limits: Lancaster Fells.
Parent Unit: Claughton Member (CLAU)
Previous Name(s): Claughton Flag Series (*502)
Barncroft Beck Member [Obsolete entry, use BACB] (-1963)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Westend Beck and adjacent disused brickpit, Claughton. 
Reference Section  Greenholes Beck, Caton Moor. 
Partial Type Section  Barncroft Beck and adjacent disused brickpits, Claughton. 
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, JN J, 1998. Geology of the country around Lancaster. Memoir of the British Geological Survey, Sheet 59 (England and Wales). 
Moseley, F, 1954. The Namurian of the Lancaster Fells. Quarterly Journal of the Geological Society of London, Vol.109, 423-454. 
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