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The BGS Lexicon of Named Rock Units — Result Details

Cheviot Glacigenic Subgroup

Computer Code: CHVG Preferred Map Code: notEntered
Status Code: Full
Age range: Dimlington Stadial (QDD) — Dimlington Stadial (QDD)
Lithological Description: Suite of sandy diamictons (till, morainic and solifluction deposits), sand, gravel, silt and clay originating from the Cheviot Hills. The deposits contain clasts derived predominantly from volcanic and intrusive rocks (basalt, andesite and granite) of the Cheviot Hills. Varying proportions of Lower Palaeozoic wacke sandstone and siltstone are also present near the western limits of the subgroup. Tills are generally matrix-supported diamictons with characteristically brownish grey or yellowish grey matrices. However, locally they can be reddish brown either where the diamictons are weathered or are derived from red strata (e.g. Devonian outcrops).
Definition of Lower Boundary: Unconformable contact with bedrock. Bedrock is commonly weathered to depths of several metres.
Definition of Upper Boundary: Unconformable contact with peat or fluvial deposits of the Britannia Catchments Group (Tweed Catchments or Northumbria Catchments subgroup).
Thickness: Up to 10 m.
Geographical Limits: Distributed over the Cheviot Hills massif.
Parent Unit: Caledonia Glacigenic Group (CALI)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Uplands of the Cheviot Hills between Carter Bar and Harehope, south-east of Wooler. Carruthers et al., 1932. 
Type Section  8 m section of in situ till overlain by soliflucted till and an upper clast-rich layer of soliflucted gelifractate derived from andesite outcrops upslope, Makendon, upper reaches of the Coquet Valley, Northumberland. Douglas and Harrison, 1985, 1987. 
Reference(s):
Mitchell,W A.2008.Quaternary geology of part of the Kale water catchment,Western Cheviot Hills,southern Scotland.Scottish Journal of Geology, Vol.44, 51-63 
McMillan, A A, Hamblin, R J O, and Merritt, J W. 2011. A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) superficial deposits of Great Britain and the Isle of Man. British Geological Survey Research Report, RR/10/03. 343pp. 
Everest, J, Bradwell, T and Golledge, N. 2005. Subglacial landforms of the Tweed palaeo-ice stream. Scottish Geographical Journal, Vol.121. 163-173. 
Douglas, T D, and Harrison, S. 1985. Periglacial landforms and sediments in the Cheviots. 68-76 in Field Guide to periglacial landforms of Northern England.Boardman,J. (editor). Quaternary Research Association. 
Douglas, T D and Harrison, S. 1987. Late Devensian slope deposits in the Cheviot Hills. 68-76 in Periglacial processes and landforms in Britain and Ireland. Boardman,J.(editor).(Cambridge:Cambridge University Press) 
Mitchell,W A. 2005. A reconnaisance of the superficial deposits of the Kale water,Cheviot Hills,Roxburghshire.BGS Internal Report IR/05/163 
Carruthers, R G, Burnett, G A and Anderson, W. 1932. The geology of the Cheviot Hills. Memoir of the Geological Survey of Great Britain, Sheets 3 and 5 (England and Wales). 
Clapperton,C M.1970. On the evidence for a Cheviot ice cap.Transactions of the Institute of British Geographers, Vol.50,115-126 
Douglas, T. 1991. Glacial deposits of Northumbria. 169-174 in Glacial deposits in Britain and Ireland. Ehlers, J, Gibbard, P L and Rose, J. (editors). (Rotterdam:Balkema Press) 
Geological Survey of Great Britain. Explanation of Sheet 26. Unpublished manuscript 1880s. Additional Information File. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E003 E005