The BGS Lexicon of Named Rock Units — Result Details

Yorkshire Dales Till Formation

Computer Code: YDTI Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Generally dark grey to greyish brown, extremely compact, stony sandy silty clay diamicton with clasts dominated by, or exclusively, local Carboniferous lithologies (limestone, sandstone, granule-conglomerate and mudstone). Mostly mudstone and limestone at Partial Type Section. Some clasts of wacke sandstone and siltstone from the Howgill Fells occur in tills in upper Wensleydale.
Definition of Lower Boundary: Generally a sharp uneven contact on bedrock, but locally a complex gradational glaciotectonic contact with fractured or decomposed bedrock.
Definition of Upper Boundary: Generally the ground surface or overlain unconformably by glaciofluvial sand and gravel or younger Superficial deposits.
Thickness: Generally less than 10m
Geographical Limits: The Yorkshire Dales south of the Stainmore Gap and north of the Devensian glacial limit.
Parent Unit: North Pennine Glacigenic Subgroup (NPEG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  The Yorkshire Dales south of the Stainmore Gap (between Appleby-in-Westmoreland and Barnard Castle) and north of the Devensian glacial limit. Mitchell (1991): Howard and Macklin (1998) 
Partial Type Section  River cliff section in a drumlin on the northern bank of the Widdale Beck at its confluence with the Snaizeholme Beck 4km SW of Hawes Rose (1991) 
Howard, A J. and Macklin, M G. (eds.) 1998.The Quaternary of the Eastern Yorkshire Dales: Field Guide. Quaternary Research Association,London. 
Rose,J.1991.Drumlin sediments,Widdale Side.In Mitchell,W.A.(ed.) Western Pennines:Field Guide.Quaternary Research Association,London. 
Mitchell,W.A.(ed.) 1991.Western Pennines:Field Guide.Quaternary Research Association,London. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable