The BGS Lexicon of Named Rock Units — Result Details

Cumbria-Lancashire Catchments Subgroup

Computer Code: CLCA Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Holocene Epoch (QH)
Lithological Description: Alluvial silt, sand, clay and gravel with some peat. Associated River Terraces are dominated by sand and gravel, gravelly sand or sandy gravel with rare clay and silt.
Definition of Lower Boundary: Probably unconformable and in places strongly incised into highly variable sediments of the Caledonia or Albion Glacigenic groups and bedrock.
Definition of Upper Boundary: Ground surface or unconformable below artificial deposits.
Thickness: Highly variable depending on the relative stratigraphical positions of each of the component units. In the major river valleys the thickness may vary between 2 and 5m, but probably does not exceed 10m. For deposits flanking the major river valleys, the thickness probably varies between 1 and 3m.
Geographical Limits: West and south Cumbria and Lancashire: the westerly and southerly catchments of the Lake District and Lancashire west of the Pennines between Whitehaven and Liverpool, including the catchments of the river valleys and their tributaries of the Rivers Lune, Wyre, Ribble, Ehan and Esk.
Parent Unit: Britannia Catchments Group (BCAT)
Previous Name(s): Lytham Formation (LTHM)
Lytham Formation (LTHM)
Swettenham Formation [Obsolete Name and Code: Use CLCA, CNWCA, LUNV, MSYVA] (-4546)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The westerly and southerly catchments of the Lake District and Lancashire west of the Pennines between Whitehaven and Liverpool, including the catchments of the river valleys and their tributaries of the Rivers Lune, Wyre, Ribble, Ehen and Esk and small lake basins and peat bogs of the district (e.g. Blelham). 
Reference(s):
McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. 
Thomas, G S P. 1999. Northern England. 91-98 in Bowen, D Q (Editor), A revised correlation of Quaternary and Neogene 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