The BGS Lexicon of Named Rock Units — Result Details

Harestones Rhyolite

Computer Code: CFCOH Preferred Map Code: notEntered
Status Code: Full
Age range: Ordovician Period (O) — Ordovician Period (O)
Lithological Description: A quartz-phyric rhyolite. Radiometric age: 419 +/- 4 Ma (Rb-Sr, whole rock) (Rundle, 1979); considered by many authors including Millward (2002) to have been re-set.
Definition of Lower Boundary: Not defined.
Definition of Upper Boundary: Not defined.
Thickness: A near-vertical mass emplaced within the Drygill Shale Formation at the northern margin of the Carrock Fell Complex.
Geographical Limits: Carrock Fell, Cumbria.
Parent Unit: Carrock Fell Complex (CFCO)
Previous Name(s): Harestones Rhyolite [In Carrock Fell Complex] (-3916)
Harestones Felsite [Obsolete Name And Code: Use CFCOH] (HARE)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Great Lingy Hill. Millward (1999). 
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. 
Rundle, C C, 1979. Ordovician intrusions in the English Lake District. Journal of the Geological Society of London, Vol.136, 29-38. 
Millward, D. 2002. Early Palaeozoic magmatism in the English Lake District. Proceedings of the Yorkshire Geological Society, Vol. 54, Part 2, 65-93. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E023