| Computer Code: |
THGTI |
Preferred Map Code: |
TH |
| Status Code: |
Full |
| Age range: |
Anglian Stage (QA)
— Wolstonian Stage (QO) |
| Lithological Description: |
Extremely compact, silty sandy gravelly diamicton containing clasts mainly of slate. "Borrowdale Volcanic Group" lithologies and Threlkeld microgranite. Dark grey at base becoming increasingly weathered upwards to yellowish brown with olive brown, orange and white mottling where it has been cryoturbated. Most clasts are decomposed towards top and are commonly bleached. The deeply weathered zone of the unit is named formally as the Troutbeck Palaeosol. |
| Definition of Lower Boundary: |
Generally an uneven, unconformable boundary with slate bedrock, but locally a thin unit of weathered sand and gravel intervenes. Bedrock commonly decomposed. |
| Definition of Upper Boundary: |
Generally a sharp, planar, or gradational glacitectonic boundary with greyish brown stony clay diamicton (Threlkeld Till Formation). |
| Thickness: |
To 15m |
| Geographical Limits: |
Vale of Thelkeld, Cumbria. |
| Parent Unit: |
Central Cumbria (Albion) Glacigenic Subgroup (CCAG)
|
| Previous Name(s): |
Thornsgill Formation [Obsolete Name and Code: Use THGTI]
(-2482)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
River cliff sections in the banks of the Thornsgill Beck, 1km south of Troutbeck Head, Cumbria. Boardman (1981, 1991, 2001) |
| Partial Type Section |
River sections in the banks of the Mosedale Beck, 3km south of Wallthwaite, Cumbria. Boardman (1981, 1991, 2000). |
| Reference(s): |
| 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 (editor). Quaternary Research Association, London, 128pp. |
| 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. 2002. Thornsgill and Mosedale, 46-51 in Quaternary of Northern England. Geological Conservation Review Series, No.25. Huddart, D, and Glasser, N F (editors). (Peterborough: Joint Nature Conservation Committee.) 745pp. |
| Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
