The BGS Lexicon of Named Rock Units — Result Details

Alturlie Gravels Formation

Computer Code: ALGR Preferred Map Code: SYMB
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Sand and gravel, typically a deltaic coarsening-upwards sequence. Origin thought to be glaciomarine.
Definition of Lower Boundary: Gradational, from the Ardersier Silts Formation below, or unconformable, with lodgement till or bedrock below.
Definition of Upper Boundary: Unconformable with Late Devensian raised marine deposits above, or the present ground surface.
Thickness: At least 20m
Geographical Limits: The area surrounding the southern shore of the inner Moray Firth, between Inverness and Elgin.
Parent Unit: Banffshire Coast and Caithness Glacigenic Subgroup (BCD)
Previous Name(s): Glacial Sand And Gravel (GSG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Mid Coul Gravel Pit, Tornagrain, 12km east-north-east of Inverness. 
Partial Type Section  Bothyhill Gravel Pit, Alturlie Point. See Merritt, 1990. 
Reference(s):
Merritt, J W, 1990. New evidence for ?glaciomarine deltaic deposits at Alturie Gravel Pit. 102-105 in Auton, C A, Firth, C R and Merritt, J W. Beauly to Nairn: Field Guide. Quaternary Research Association, Cambridge. 
Merrit, J W, Auton, C A, and Firth. C R. 1995. Ice-proximal glaciomarine sedimentation and sea-level change in the Inverness area, Scotland: A review of the deglaciation of a major ice stream of the British Late Devensian ice sheet. Quaternary Science Reviews, Vol.14, 289-329. 
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:
S084