The BGS Lexicon of Named Rock Units — Result Details

Northwest Highlands Glacigenic Subgroup

Computer Code: NWHG Preferred Map Code: NWH
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: A suite of glacial, glaciofluvial and glaciolacustrine deposits that contain clasts derived predominantly from Lewisian, Torridonian, Cambrian, Caledonian igneous and Moine psammitic rocks of the northern Highlands. Including sandy diamictons (till), sand, gravel, silt and clay. Deposited by ice that radiated outwards from an ice divide positioned inland of the western seaboard of the Northern Highlands.
Definition of Lower Boundary: Sharp, unconformable contact with bedrock.
Definition of Upper Boundary: Ground surface or unconformable contact with various Flandrian deposits, predominantly peat.
Thickness: To 20m
Geographical Limits: The Northwest Highlands north of the Great Glen, and the Inner Hebrides from Mull northwards, but excluding Caithness, the hinterland of Inverness and the Western Isles.
Parent Unit: Caledonia Glacigenic Group (CALI)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The Northwest Highlands north of the Great Glen and the Inner Hebrides from Mull northwards, but excluding Caithness, the hinterland of Inverness and the Western Isles. See also the stratotypes of constituent formations, including the Dunbeath Till. 
Reference(s):
McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable