The BGS Lexicon of Named Rock Units — Result Details

Spengill Member

Computer Code: SPN Preferred Map Code: notEntered
Status Code: Full
Age range: Hirnantian Age (OH) — Rhuddanian Age (SR)
Lithological Description: Nodular limestone and pale grey mudstone.
Definition of Lower Boundary: Base of lowest nodular limestone or massive mudstone above the laminated mudstone of the Ashgill Formation.
Definition of Upper Boundary: Base of the black graptolitic mudstone of the main part of the Skelgill Formation.
Thickness: 0.4-1.8m
Geographical Limits: Howgill Fells, the Lake District, Cross Fell and the Craven Inliers.
Parent Unit: Skelgill Formation (SKB)
Previous Name(s): Basal Beds (-3221)
Alternative Name(s): none recorded or not applicable
Type Section  100m up Spen Gill from its confluence with Stockless Gill. 
Scott, R W and Kneller, B C, 1990. A report on the Ashgill and Llandovery age rocks of Sheet 38 (Ambleside). British Geological Survey Technical Report WA/90/63. 
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. 
Rickards, R B, 1970. The Llandovery (Silurian) graptolites of the Howgill Fells (northern England). Monograph Palaeontological Society, London, 1-108. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable