The BGS Lexicon of Named Rock Units — Result Details

Inverness Glacigenic Subgroup

Computer Code: INVG Preferred Map Code: INV
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Suite of glacial, glaciofluvial, glaciolacustrine and glaciomarine deposits that contain clasts derived predominantly from the comminution of Devonian (Old Red Sandstone) sandstone, siltstone and conglomerate. Including sandy diamictons (till), sand, gravel, silt and clay.
Definition of Lower Boundary: Sharp, unconformable, uneven contact with bedrock.
Definition of Upper Boundary: Ground surface or unconformable contact with various Flandrian deposits.
Thickness: To 40m
Geographical Limits: The hinterland of the Moray Firth, including the northeastern end of the Great Glen, the southern shores of the Moray Firth as far east as Buckie, the Black Isle, and the land surrounding the Cromarty and Dornoch firths.
Parent Unit: Caledonia Glacigenic Group (CALI)
Previous Name(s): Central Grampian Drift Group (-772)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The hinterland of the Moray Firth, including the northeastern end of the Great Glen, the southern shores of the Moray Firth as far east as Buckie, the Black Isle, and the land surrounding the Cromarty and Dornoch firths. See also the stratotypes of constituent formations, including the Finglack Till, Kincrdy Silts, Red Craig Gravels, Athais Till, Allt Odhar Peat, Odhar Gravel and Dalcharn Palaeosol. 
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. 
Fletcher, T P et al. 1996. Geology of the Fortrose and eastern Inverness district. Memoir of the British Geological Survey, Sheet 84W (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable