The BGS Lexicon of Named Rock Units — Result Details

Coylumbridge Formation

Computer Code: COYB Preferred Map Code: COL
Status Code: Pending Upgrade
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Flaggy, laminated feldspathic psammite and micaceous psammite with minor bands of schistose semipelite; quartzite locally important.
Definition of Lower Boundary: Conformable and transitional with Kincraig Formation but poorly exposed. Marked by change to dominantly psammite.
Definition of Upper Boundary: Conformable transition up into more siliceous and feldspathic psammites of the Glen Spean Subgroup south of the Cairngorm Mountains.
Thickness: 500m to 1km.
Geographical Limits: Northern Cairngorm Mountains and Mid-Speyside, Central Highlands of Scotland, sheets 74E and 64E.
Parent Unit: Corrieyairack Subgroup (GRCO)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Section in River Druie immediately south of Coylumbridge Village. 
Reference Section  Creag nan Gall to Stac na H-iolaire upper slopes. 
Reference(s):
Highton, A J, 1999. Solid geology of the Aviemore district, Memoir for 1:50000 geological sheet 74E [Scotland]. London: The Stationery Office. 97pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S074