The BGS Lexicon of Named Rock Units — Result Details

Stanwix Shales Formation [Obsolete Name And Code: Use MMG]

Computer Code: STSH Preferred Map Code: STSH
Status Code: Index Level
Age range: Triassic Period (T) — Triassic Period (T)
Lithological Description: Red and green micaceous and sandy mudstones carbonate-rich (dolomite) in upper portions. Rare basal mudstone breccias, gypsum and halite locally.
Definition of Lower Boundary: Conformable base resting on either Kirklinton Sandstone or St Bees Sandstone.
Definition of Upper Boundary: Poorly known but appears to be conformably overlain by marine mudstones of Penarth Group in Carlisle area.
Thickness: 300m+
Geographical Limits: Carlisle Basin, BGS sheets 16, 17, 22, 23.
Parent Unit: Mercia Mudstone Group (MMG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  West bank of River Eden, north of Kirkandrews-on-Eden. 
Reference(s):
Eastwood,T, Hollingworth, S E, Rose, W C C and Trotter, F M. 1968. Geology of the country around Cockermouth and Caldbeck. Memoir of the Geological Survey of Great Britain, England and Wales, Sheet 23. 
Howard, A S, Warrington, G, Ambrose, K, and Rees, J G. 2008. A formational framework for the Mercia Mudstone Group (Triassic) of England and Wales. British Geological Survey Research Report, RR/08/04. 
Holmes, 1899. The geology of the country around Carlisle. Memoir of the Geological Survey. 
Dixon, E E L, Maden J, Trotter, F M, Hollingworth, M A and Tonks, L H. 1926. The geology of the Carlisle, Longtown and Silloth District. Memoir of the Geological Survey of England and Wales. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E023 E022 E018