The BGS Lexicon of Named Rock Units — Result Details

Metamorphic Aureole, Cairnsmore Of Fleet Pluton

Computer Code: MACF Preferred Map Code: notEntered
Status Code: Full
Age range: Devonian Period (D) — Devonian Period (D)
Lithological Description: Ordovician strata of the Moffat Shale Group, Shinnel and Glen Lee formations, Silurian strata of the Gala Group and Siluro-Devonian minor intrusions are metamorphosed to biotite hornfels or, locally, calc-silicate skarn within the thermal metamorphic aureole of the Cairnsmore of Fleet Pluton.
Definition of Lower Boundary: Outer boundary of the aureole is mapped at the first observation of a purple tint to sandstone, caused by the development of microscopic biotite in the matrix.
Definition of Upper Boundary: Margin of the Cairnsmore of Fleet Pluton.
Thickness: Mapped as between 800m and 6km in width.
Geographical Limits: Aureole rocks are exposed all around the Cairnsmore of Fleet Pluton from Creetown in the south [NX 47 58], Blackcraig in the west [NX 64 44], Loch Ken to the east [NX 65 73] and St Johns Town of Dalry to the north [NX 62 80].
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Traverse up Grey Mare's Tail Burn from the margin of the Cairnsmore of Fleet, through the aureole rocks to the mapped limit of thermal metamorphosed rocks in Poultrybuie Burn. 
Reference Section  Culchronchie Burn to Culchronchie Hill. [Barnes, in press]. 
Reference(s):
Barnes, R P, (in prep). The geology of the Kirkcowan, Wigtown and Whithorn districts. Memoir of the British Geological Survey, Sheets 4W, 4E and 2 (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S005 S006 S009 S008