The BGS Lexicon of Named Rock Units — Result Details

Beoil Schist Formation

Computer Code: BEOS Preferred Map Code: BeoS
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Schistose muscovite-rich pelite with a scattered garnet porphyroblasts and pods of vein quartz. Unusually mica-rich. Locally contains sporadic carbonate or graphite.
Definition of Lower Boundary: Transitional boundary with Beoil Quartzite Formation; boundary taken at top of last quartzite rib.
Definition of Upper Boundary: Apparently transitional boundary with Meall Dubh Striped Pelite; highly tectonised.
Thickness: 5 - 90m ; probably much tectonic thinning.
Geographical Limits: Main development in Strath Fionan [NN 7257 7556]. Also occurs sporadically as far west as Allt Druidhe [NN 642 5712] and as far east as the Tomintianda Burn [NN 809 606]. Not present east of the Loch Tay Fault, where it is tectonically excised; however some of the rocks of the 'Banvie Burn Series' may be equivalent.
Parent Unit: Lochaber Subgroup (DALO)
Previous Name(s): Beoil Schist (-686)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  On south-facing scarp 700m west of Lochan Beoil Chataiche. 
Reference(s):
Harris, A L, Haselock, P J, Kennedy, M J and Mendum, J R, 1994. The Dalradian Supergroup in Scotland, Shetland and Ireland. 33-53 in Gibbons, W E and Harris, A L (editors). A revised correlation of Precambrian rocks in the British Isles. Special Report of the Geological Society, London, No.22. 
Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). 
Stephenson, D and Gould, D. 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. 
Treagus, J E and King, G, 1978. A complete Lower Dalradian succession in the Schiehallion district, central Perthshire. Scottish Journal of Geology, Vol.14, 157-166. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S055