The BGS Lexicon of Named Rock Units — Result Details

Farragon Volcanic Formation

Computer Code: FAVO Preferred Map Code: symb
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Hornblende schist, fine-grained with layers and lenses of hornblende psammite. Interfingers with the Ben Lawers Schist Formation in the east of outcrop and locally with intercalated psammite in the upper parts of the Formation.
Definition of Lower Boundary: Base of dominantly fine-grained amphibolitic succession overlying the Ben Lawers Schist Formation.
Definition of Upper Boundary: Gradational boundary with Ben Lui Schist Formation located where psammite and semipelite become the dominant lithology.
Thickness: Generally 200 to 300m, although thicker in the Ben Vrackie area [NN 94 63].
Geographical Limits: Farragon Hill area to Glen Shee.
Parent Unit: Easdale Subgroup (DBED)
Previous Name(s): Farragon Beds [Obsolete Name And Code: Use FAVO] (DBFB)
Farragon Volcanic Formation (FAVO)
Farragon Beds (*184)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Creag Uisge area. 
Type Area  Farragon Hill. 
Reference(s):
Crane, A, Goodman, S, Krabbendam, M K, Leslie, A G, Paterson, I B, Robertson, S and Rollin, K, 1996. Geology of the Glen Shee district. Memoir of the British Geological Survey, Sheet 56W and adjacent areas (Scotland). 
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. 
Sturt, B A, 1960. The geological structure of the area south of Loch Tummel. Quarterly Journal of the Geological Society of London, Vol.117, 131-156. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S056 S055 S055 S065