The BGS Lexicon of Named Rock Units — Result Details

Ullapool Gravel Formation

Computer Code: ULGR Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Clast-supported, crudely bedded, cobble-grade, glaciofluvial gravel with sporadic intercalated sand beds. Clasts are typically rounded-subrounded and imbricated. Structures in the gravel include normal grading and large-scale planar cross beds; sandy units occasionally preserve ripple bedding, silt stringers and evidence of current reworking.
Definition of Lower Boundary: Unconformable on, and locally oversteps, older glacial units.
Definition of Upper Boundary: Locally overlain by the Allt an t-Srathain Member. More commonly exposed at or near to present day land surface, or sea bed where submerged.
Thickness: >30 m thick at Ullapool.
Geographical Limits: NW Scottish coastline, between Loch Ewe and Kyle of Tongue.
Parent Unit: Northwest Highlands Glacigenic Subgroup (NWHG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Unmade road cutting in Ullapool. Stoker, M S and Bradwell, T. In press. Quaternary geology of the Summer Isles region - a brief explanation of the marine environment map. Sheet Explanation of the British Geological Survey. 1:50 000 Special Sheet Summer Isles (Scotland). 
Reference(s):
Stoker, M S and Bradwell, T. In press. Quaternary geology of the Summer Isles region - a brief explanation of the marine environment map. Sheet Explanation of the British Geological Survey. 1:50 000 Special Sheet Summer Isles (Scotland). 
Bradwell, T and Stoker, M S. 2010. Quaternary Lithostratigraphy of the NW Highlands. In: Lukas, S. & Bradwell, T. (eds), The Quaternary of Western Sutherland and adjacent areas. (London: Quaternary Research Association), 29-37. 
Stoker, M S, Bradwell, T, Howe, J A, Wilkinson, I P & McIntyre, K. 2009. Lateglacial ice-cap dynamics in NW Scotland: evidence from the fjords of the Summer Isles region. Quaternary Science Reviews, 28, 3161-3184. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S101