The BGS Lexicon of Named Rock Units — Result Details

Shoulder O'Craig Vent

Computer Code: SOCG Preferred Map Code: SCV
Status Code: Index Level
Age range: Emsian Age (DE) — Emsian Age (DE)
Lithological Description: Subvolcanic explosion-breccia composite vent, comprising: carbonated vent agglomerate of wacke clasts in a fine-grained comminuted igneous matrix, altered bioitite-bearing olivine basaltic intrusion and kersantite intrusions.
Definition of Lower Boundary: The intrusive contacts with the country rock of Llandovery Turbidites is poorly exposed, which together with diffuse internal structures, makes field relationships difficult to define.
Definition of Upper Boundary: none recorded or not applicable
Thickness: Thickness not known, but individual vents vary from 5 x 50 m, to 250 x 100m. This unit may be one vent with two small subsidiary vents.
Geographical Limits: Kirkcudbright Sheet 5W (Scotland)
Parent Unit: Black Stockarton Moor Subvolcanic Complex (BSTM)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  A composite vent on the west side of Kirkcudbright Bay at Shoulder o' Craig, about 2 km south-west of Kirkcudbright. Rock, Cooper & Gaskarth. 1986 
Leake, R C and Cooper, C. 1983. The Black Stockarton Moor Subvolcanic Complex, Galloway. Journal of the Geological Society, London. Vol. 140, 665-676. 
Rock, N M S, Cooper, C and Gaskarth, J W. 1986 Late Caledonian subvolcanic vents and associated dykes in the Kirkcudbright area, Galloway, South-West Scotland. Proceedings of the Yorkshire Geological Society, Vol. 46, 29-37. 
Lintern, B C and Floyd, J D. 2000. Geology of the Kirkcudbright-Dalbeattie District. Memoir of the British Geological Survey, Sheets 5W, 5E and part of 6W (Scotland). 
Stone, P. 1999. Shoulder O' Craig. 556-559 in Caledonian igneous rocks. Stephenson, D, Bevins, R E, Millward, D, Highton, A J, Parsons, I, Stone P, and Wadsworth, W J. GCR Series, No.17. ( Peterborough: Joint Nature Conservation Committee.) 
Stone, P, Cheeney, R F and White, D E, 1996. Excursions in geology in southwest Scotland. An Excursion Guide, p. 49-51. (Keyworth, Nottingham: British Geological Survey.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used: