The BGS Lexicon of Named Rock Units — Result Details

Loch Broom Till Formation

Computer Code: LBTI Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Grey (5Y 6/1) to reddish brown (2.5Y 5/6), overconsolidated, muddy and sandy diamicton, gravel to boulder grade, matrix to clast supported, with a strong subhorizontal clast fabric.
Definition of Lower Boundary: Unconformable boundary with bedrock.
Definition of Upper Boundary: Sharp contact with Assynt Glacigenic Formation.
Thickness: Up to 20m thick on Martin Bank (offshore); mostly <5m onshore.
Geographical Limits: Overlies bedrock onshore and offshore the Summer Isles region of Wester Ross. It is separated from The Minch by a wide zone of bedrock.
Parent Unit: Northwest Highlands Glacigenic Subgroup (NWHG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Auchlunachan Burn, off unclassified road, 500 m SW of Inverbroom Lodge. Bradwell, T. & 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. 
Type Section  Allt an t-Srathain burn, adjacent to unclassified road, about 500 m to the SE of Rhue. 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):
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 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). 
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