The BGS Lexicon of Named Rock Units — Result Details

Faughlin Lava Member

Computer Code: FGHL Preferred Map Code: notEntered
Status Code: Full
Age range: Arundian Substage (CJ) — Asbian Substage (CR)
Lithological Description: The Faughlin Lava Member consists predominantly of microporphyritic trachybasalt and basaltic-trachyandesite lavas (hawaiitie to mugearite). A single plagioclase-macrophyric trachybasalt (hawaiite of 'Markle' type) is also present and tuff and agglomerate are present locally at the base of the member. The source of this member is probably local.
Definition of Lower Boundary: The lower boundary of the Faughlin Lava Member is conformable or disconformable on the underlying Carron Bridge Lava Member, and is marked in the small stream due south of bridge over the River Carron [748 838] by a tuff overlying trachybasalt.
Definition of Upper Boundary: The Faughlin Lava Member is overlain by the Campsie Lava Member. The lithological change is to mostly plagioclase-microphyric basalt and trachybasalt (of 'Jedburgh' type).
Thickness: 35 m
Geographical Limits: The member is restricted to the eastern part of the Campsie Block and specifically to two small areas of the north-eastern Kilsyth HIlls, north-east of Glasgow.
Parent Unit: Clyde Plateau Volcanic Formation (CPV)
Previous Name(s): Faughlin Lavas (-4648)
Alternative Name(s): none recorded or not applicable
Reference Section  Unnamed tributary of the River Carron, north-east Kilsyth Hills, north-east of Glasgow Craig, 1980 
Type Area  North-eastern Kilsyth Hills, north-east of Glasgow Forsyth et al, 1996, after Craig, 1980 
Forsyth, I H, Hall, I H S and McMillan, A A. 1996. Geology of the Aidrie district. Memoir of the British Geological Survey, Sheet 31W (Scotland). 
Craig, P.M. 1980 The Volcanic Geology of the Campsie Fells area, Stirlingshire. Unpublished PhD thesis, University of Lancaster. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: