The BGS Lexicon of Named Rock Units — Result Details

Cystoid Limestone Member

Computer Code: CYO Preferred Map Code: notEntered
Status Code: Full
Age range: Ashgill Series (OA) — Ashgill Series (OA)
Lithological Description: Pale grey argillaceous limestone.
Definition of Lower Boundary: Base of limestone above grey mudstones.
Definition of Upper Boundary: Top of limestone, transitional to grey mudstone.
Thickness: 1.5 to 3m
Geographical Limits: Howgill Fells - may correlate with the Troutbeck Member of the Lake District.
Parent Unit: Ashgill Formation (AHL)
Previous Name(s): Staurocephalus Limestone [Obsolete Name and Code: Use SWL, CYO] (-3345)
Cystoid Limestone [Obsolete Name and Code: Use CYO] (-181)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Odd Gill, 300m east of its confluence with Wandale Beck. 
Reference(s):
Marr, J E, 1892. The Coniston Limestone Series. Geological Magazine, Vol.(3) 9, 97-110. 
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. 
Ingham, J K, 1966. The Ordovician rocks in the Cautley and Dent districts of Westmorland and Yorkshire. Proceedings of the Yorkshire Geological Society, Vol.35, 455-505. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable