The BGS Lexicon of Named Rock Units — Result Details

Carn Mairg Quartzite Formation

Computer Code: DBCM Preferred Map Code: CMQ
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Massive white pebbly quartzite and rusty gritty psammite, with local pink feldspathic quartzite and calcareous semipelite.
Definition of Lower Boundary: First appearance of massive pebbly quartzite within 80m transition zone from impure quartzites and semipelites of Killiecrankie Schist Formation.
Definition of Upper Boundary: Point within transitional sequence where micaceous, graphitic pelite typical of Ben Eagach Schist Formation dominates over quartzite.
Thickness: 0 - 900m in Sheet 55W
Geographical Limits: From Creag Sparadain [NN 968 653], where it is cut off by the Killiecrankie Slide, southwards via the north side of Beinn Eagagach [NN 855 575] and Carn Mairg [NN 683 515], to Loch Awe [NN 11 26], where it is cut off by the Etive Complex.
Parent Unit: Easdale Subgroup (DBED)
Previous Name(s): Carn Mairg Quartzite (-194)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Summit ridge of Carn Mairg from boundary with Killiecrankie Schist (to north) to boundary with Ben Eagach Schist (to south). 
Reference(s):
Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). 
Bailey, E B, 1925. Perthshire tectonics: Loch Tummel, Blair Atholl and Glen Shee. Transactions of the Royal Society of Edinburgh, Vol.53, 671-698. 
Barrow, G, Grant Wilson, J S and Cunningham Craig, E H, 1905. The geology of the country around Blair Atholl, Pitlochry and Aberfeldy. Memoir of the British Geological Survey, Scotland (Sheet 55). 
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. 
Bailey, E B and McCallien, W J, 1937. Perthshire tectonics: Schiehallion to Glen Lyon. Transactions of the Royal Society of Edinburgh, Vol.59, 79-117. 
Stephenson, D and Gould, D , 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S055 S055 S054 S046 S045 S046 S046