The BGS Lexicon of Named Rock Units — Result Details

Thornton Limestone Member

Computer Code: THTL Preferred Map Code: ThtL
Status Code: Full
Age range: Chadian Substage (CI) — Chadian Substage (CI)
Lithological Description: Packstones, wackestones and subordinate grainstones predominantly wavy-bedded, muddy, pale to dark grey, bioclastic and locally cherty, interbedded with variable amounts of dark-grey calcareous mudstone and siltstone. Bioturbation is common.
Definition of Lower Boundary: Overlies the Chatburn Limestone Group.
Definition of Upper Boundary: Overlain unconformably by the Hodder Mudstone Formation in the Worston Shale Group.
Thickness: To 200m
Geographical Limits: Confined to the Craven Basin of Lancashire and Yorkshire.
Parent Unit: Clitheroe Limestone Formation (CLL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Disused quarries 0.85km northwest of Stainton Hall (Arthurton and others, 1988, p.44). Neither base nor top exposed. 
Reference(s):
Earp, J R, Magraw, D, Poole, E G, Land, D H and Whiteman, A J, 1961. Geology of the country around Clitheroe and Nelson. Memoir of the Geological Survey of Great Britain, Sheet.68, England and Wales, pp.346. 
Wadge, A J et al. 1983. Mineral reconnaissance surveys in the Craven Basin. Institute of Geological Sciences Mineral Reconnaissance Programme Report, Vol.66. 
Moseley, F, 1962. The structure of the south-western part of the Sykes Anticline, Bowland, West Yorkshire. Proceedings of the Yorkshire Geological Society, Vol.33, p.287-314. 
Riley N J. 1990. Stratigraphy of the Worston Shale Group (Dinantian) Craven Basin, north-west England. Proceedings of the Yorkshire Geological Society, Vol. 48, 163-187. 
Hudson, R G S and Dunnington, H V, 1944. The Carboniferous rocks of the Swindon Anticline, Yorkshire. Proceedings of the Geologists' Association, Vol.55, p.195-215. 
Arthurton, R S, Johnson, E W and Mundy, D J C. 1988. Geology of the country around Settle. Memoir of the British Geological Survey, Sheet 60 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E059 E067 E060