The BGS Lexicon of Named Rock Units — Result Details

Threlkeld Till Formation

Computer Code: TKTI Preferred Map Code: TK
Status Code: Pending Upgrade
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Very compact, olive grey, sandy, silty, clayey, stony diamicton containing clasts mainly of "Borrowdale Volcanic Group" lithologies, slate and Threlkeld microgranite. Locally includes masses of weathered diamicton (Thornsgill Till) at base. Commonly weathered to yellowish grey.
Definition of Lower Boundary: Generally an unconformable boundary on bedrock. Locally a sharp, planar, or gradational glacitectonic boundary with yellowish brown sandy gravelly clay diamicton (Thornsgill Till Formation).
Definition of Upper Boundary: Mostly ground surface or overlain unconformably by glaciofluvial sand and gravel.
Thickness: To 25m
Geographical Limits: Northeast Lake District, Cumbria.
Parent Unit: Central Cumbria Glacigenic Subgroup (CCGL)
Previous Name(s): Threlkeld Member (-571)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  River cliff sections in the banks of the Barrow Beck, 3km northwest of Troutbeck Head, Cumbria. Boardman 1991, 
Partial Type Section  River cliff sections in the banks of the Mosedale Beck, 3km south of Wallthwaite, Cumbria. Boardman (1981, 1991, 2001), 
Reference(s):
Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. 
Boardman, J. 1991. Glacial deposits in the English Lake District, 231-260 in Glacial deposits in Great Britain and Ireland. Ehlers, J, Gibbard, P L and Rose, J (editors). (Rotterdam:Balkema.) 
Boardman, J, Lowe, J J, Holyoak, D T, and Wilson, P. 1981. Northeastern Lake District: The valleys of Mosedale and Thornsgill, 7-39 in Field Guide to Eastern Cumbria. J Boardman (ed.) Quaternary Research Association, London, 128pp. 
Boardman, J. 2002. Thornsgill and Mosedale, 46-51 in Huddart, D and Glasser, N F (editors), Quaternary of Northern England. Geological Conservation Review Series, No.25. [Peterborough: Joint Nature Conservation Committee.] 745pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable