The BGS Lexicon of Named Rock Units — Result Details

Creag Liath Psammite Formation

Computer Code: CGLH Preferred Map Code: LI
Status Code: Full
Age range: Tonian Period (AT) — Tonian Period (AT)
Lithological Description: Interbanded gneissose psammite, siliceous psammite with subordinate micaceous psammite and semipelite. Distinctive porphyroclasts of K-feldspar common.
Definition of Lower Boundary: Conformable (if sheared) upon An Stac Semipelite and Psammite Formation (ANST); marked by incoming of psammite.
Definition of Upper Boundary: Unconformably overlain by Grampian and Appin Group rocks (Dalradian Supergroup - DALN).
Thickness: c. 400 m (maximum; estimated; deformed).
Geographical Limits: Central Highlands of Scotland. Glen Banchor - Kincraig area.
Parent Unit: Glen Banchor Subgroup (GLBA)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Creag Liath, north of Glen Banchor [NH664 007]. 
Reference Section  Creag na H'iolare - basal contacts and lower parts. 
Reference Section  Unnamed burn 300 m west of Gergask Crag. 
Reference(s):
Krabbendam, M. 2021. A stratigraphic framework for the early Neoproterozoic successions of the Northern Highlands of Scotland. UK Stratigraphic Framework Series. British Geological Survey Open Report, OR/21/072. 86pp. 
Leslie, A G, Robertson, S, Smith, M, Banks, C J, Mendum, J R, and Stephenson, D. 2013. The Dalradian rocks of the northern Grampian Highlands of Scotland. Proceedings of the Geologists' Association, Vol. 124, 263-317. 
Robertson, S, and Smith, M. 1999. The significance of the Geal Charn-Ossian steep belt in basin development in the central Scottish Highlands. Journal of the Geological Society, Vol. 156, 1175-1182. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable