The BGS Lexicon of Named Rock Units — Result Details

Rubha Guail Formation

Computer Code: TBE Preferred Map Code: notEntered
Status Code: Full
Age range: Tonian Period (AT) — Tonian Period (AT)
Lithological Description: Conglomerate at base; green-grey sandstone with epidote, cross-bedded; increasing siltstone towards top of formation.
Definition of Lower Boundary: Unconformable upon Lewisian Gneiss (L) (sheared and overturned).
Definition of Upper Boundary: Conformably overlain by Loch na Dal formation (TBLN). Incoming of interbedded sandstone-mudstone.
Thickness: Variable, maximum c. 270 m.
Geographical Limits: Northwest Scotland: Isle of Skye: Sleat.
Parent Unit: Sleat Group (TB)
Previous Name(s): Epidotic Grit Formation (-561)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Coastal section at Rubha Guail, Sleat, Skye [NG 722 150 - NG 728 159]. 
Reference(s):
Stewart, A D. 2002. The later Proterozoic Torridonian rocks of Scotland: their sedimentology, geochemistry and origin. Geological Society Memoir. Vol. 24. (The Geological Society.) 
Krabbendam, M, Bonsor, H, Horstwood, M S, and Rivers, T. 2017. Tracking the evolution of the Grenvillian foreland basin: Constraints from sedimentology and detrital zircon and rutile in the Sleat and Torridon groups, Scotland. Precambrian Research, Vol. 295, 67-89. 
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. 
Johnston, G S and Mykura, W. 1989. British regional geology: the Northern Highlands (4th edition) (London: HMSO for the British Geological Survey.) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S071 S061