The BGS Lexicon of Named Rock Units — Result Details

Ireleth Member

Computer Code: IRE Preferred Map Code: Ire
Status Code: Full
Age range: Cautleyan Stage (OU) — Cautleyan Stage (OU)
Lithological Description: Pale to dark grey, massive or thickly bedded limestone, commonly pervasively recrystallised with bedding planes which are either stylotitic or totally obscured; dolomitisation and haematite staining common in the south of the inlier with the limestone becoming cavernous and mottled brown in colour.
Definition of Lower Boundary: In Millom Park, it is a member within the Kirkley Bank Formation where it overlies volcaniclastic sandstone of the Low Scales Member; the base of the Ireleth Member is taken at the base of the limestone. Elsewhere the member overlies locally the Skiddaw Group and Borrowdale Volcanic Group.
Definition of Upper Boundary: Defined by the base of a sequence of calcareous siltstone within the main part of the Kirkley Bank Formation.
Thickness: Up to 30 m thick.
Geographical Limits: Restricted to the Millom Park and the Furness inliers, Cumbria.
Parent Unit: Kirkley Bank Formation (KKB)
Previous Name(s): Ireleth Limestone (-2866)
High Haume Limestone (-1614)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  High Haume Beacon Johnson et al., 2001. 
Reference(s):
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. 
Johnson, E W, Soper, N J, Burgess, I C, Ball, D F, Beddoe-Stephens, B, Carruthers, R M, Fortey, N J, Hirons, S, Merritt, J W, Millward, D, Roberts, B, Walker, A B and Young, B. 2001. Geology of the country around Ulverston. Memoir of the British Geological Survey, England and Wales, Sheet 48. 
Sedgwick A. 1846. On the classification of the fossiliferous slates of Cumberland, Westmoreland and Lancashire. Quarterly Journal of the Geological Society of London, Vol 2, 106 - 122. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E048