The BGS Lexicon of Named Rock Units — Result Details

Eskdale Intrusions

Computer Code: ESK Preferred Map Code: notEntered
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A pink, medium-grained muscovite granite, aphyric and porphyritic microgranite, coarse-grained granite, medium-grained granodiorite, microgranodiorite, biotite-rich granodiorite, and quartz-mica greisen locally containing topaz and quartz-andalusite rock associated with granite. The age of the granite is 450 +/- 3 Ma (U-Pb, zircon) (Hughes et al, 1996)
Definition of Lower Boundary: Two sheet-like masses of granite and granodiorite cropping out over 53 and 23 sq. km respectively, and intruded into the Skiddaw Group and the Borrowale Volcanic Group.
Definition of Upper Boundary: Not defined.
Thickness: Unspecified.
Geographical Limits: Corney Fell to Wasdale, western Lake District.
Parent Unit: Lake District Ordovician Felsic Plutonic Suite (LDFP)
Previous Name(s): Eskdale Intrusion, Granodiorite [Obsolete Code: Use ESK + Rock Type] (ESGD)
Eskdale Intrusion, Microgranite [Obsolete Code: Use ESK + Rock Type] (ESGM)
Eskdale Intrusion, Granite [Obsolete Code: Use ESK + Rock Type] (ESGR)
Eskdale Intrusion (-2174)
Eskdale Pluton (-2787)
Ennerdale Granite (-4030)
Eskdale Granodiorite (-894)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Beckfoot Quarry, Eskdale for the granite intrusion. Young (in Stephenson et al., 1999). 
Type Area  Waberthwaite (Broad Oak) Quarry,west Cumbria for the granodiorite Young (in Stephenson et al., 1999). 
Reference(s):
Young, B. 1999. Beckfoot Quarry. 194-195 in Stephenson, D, Bevins, R E, Millward, D, Highton, A J, Parsons, I, Stone, P and Wadsworth W J. Caledonian igneous rocks of the British Isles. (Peterborough: Joint Nature Conservation Committee.) 
Millward, D. 2002. Early Palaeozoic magmatism in the English Lake District. Proceedings of the Yorkshire Geological Society, Vol. 54, Part 2, 65-93. 
Young, B. 1999. Waberthwaite Quarry. 196-198 in Stephenson, D, Bevins, R E, Millward, D, Highton, A J, Parsons, I, Stone, P, and Wadsworth, W J. Caledonian igneous rocks of the British Isles.(Peterborough: Joint Nature Conservation Committee.) 
Hughes, R A, Evans, J A, Noble, S R, and Rundle, C C. 1996. U-Pb chronology of the Ennerdale and Eskdale intrusions supports sub-volcanic relationships with the Borrowdale Volcanic Group (Ordovician, English Lake District). Journal of the Geological Society, London, Vol. 153, p. 33-38. 
Millward, D, Johnson, E W, Beddoe-Stephens, B, Young, B, Kneller, B C, Lee, M K, Fortey, N J, Allen, P M, Branney, M J, Cooper, D C, Hirons, S, Kokelaar, B P, Marks, R J, McConnell, B J, Merritt, J W, Molyneux, S G, Petterson, M G, Roberts, B, Rundle, C C, Rushton, A W A, Scott, R W, Soper, N J and Stone, P. 2000. Geology of the Ambleside district. Memoir of the British Geological Survey, England and Wales, Sheet 38. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E047 E038 E048 E037