The BGS Lexicon of Named Rock Units — Result Details

Thormaid Till Member

Computer Code: THTI Preferred Map Code: symb
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Diamicton, gravelly and sandy, typically light brown with clasts of predominantly Caledonian igneous and Moine metamorphic rocks.
Definition of Lower Boundary: Unconformable on bedrock.
Definition of Upper Boundary: Holocene strata.
Thickness: Up to 5m thick.
Geographical Limits: Caithness and Sunderland west of a line between Reay and Berridale (1:50 000 sheets 115 E and W, and sheet 110).
Parent Unit: Reay Burn Till Formation (REBU)
Previous Name(s): Local Ground Moraine (-4926)
Alternative Name(s): Ladies Tent Till Member Of The Berridale Formation
Stratotypes:
Reference Section  Lady's Tent section, Langwell Water, Caithness. Hall and Whittington, 1989, p.312. 
Type Section  Trial pit CA 1448/SP2, on the western side of Loch Thormaid, Caithness. Auton, C A, Entwisle, D C and Golledge, N R. 2001. Dounreay catchment Quaternary Characterisation study: final interpretation report. British Geological Survey commissioned Report, CR/01/116. 122pp. 
Reference(s):
Crampton, C B and Carruthers, R G, 1914. The geology of Caithness. Memoir of the Geological Survey, Scotland. Sheets 110 and 116 (Scotland). 
Hall, A M and Whittington, G. 1989. Late Devensian glaciation of southern Caithness. Scottish Journal of Geology, Vol.25, 307-324. 
Auton, C A, Entwisle, D C and Golledge, N R. 2001. Dounreay catchment Quaternary Characterisation study: final interpretation report. British Geological Survey commissioned Report, CR/01/116. 122pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S116