The BGS Lexicon of Named Rock Units — Result Details

Britannia Catchments Group

Computer Code: BCAT Preferred Map Code: CAT
Status Code: Full
Age range: Mid Pleistocene (QPM) — Holocene Epoch (QH)
Lithological Description: Excluding the deposits of the Dunwich Group, the Britannia Catchments Group is established for mid-Pleistocene and younger gravels, sands and silts of fluvial and lacustrine deposits. Aeolian (cover sands and loess) and organic beds (including peat and soils) and mass movement (head) deposits are also included within the group. Fluvial deposits and related interbedded organic and lacustrine deposits are assigned formational status within subgroups defined geographically by drainage systems. Other organic, lacustrine and mass movement deposits (e.g. those representing interglacials) are assigned formational status or are defined as lithogenetic units of the Britannia Catchments Group. Clays, silt, sands, gravels and peat. Gravels are composed of clasts derived from rocks cropping out throughout Great Britain and the Isle of Man. A suite of fluvial, lacustrine, organic, mass movement, periglacial and aeolian deposits. Includes alluvium and river terrace deposits, head, and cover sands. Mid-Pleistocene - Holocene (MIS 13 - 1).
Definition of Lower Boundary: Unconformable contact with units of the Albion Glacigenic Group, the Caledonia Glacigenic Group, the Dunwich Group, the Crag Group or bedrock.
Definition of Upper Boundary: Generally the ground surface, but locally units of this group interfinger with units of the British Coastal Deposits Group.
Thickness: Up to 100 m.
Geographical Limits: Great Britain and the Isle of Man.
Parent Unit: Great Britain Superficial Deposits Supergroup (GBG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Great Britain and the Isle of Man. See also the stratotypes of constituent subgroups and formations. 
Reference(s):
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. 
McMillan, A A. 2005. A provisional Quaternary and Neogene lithostratigraphical framework for Great Britain. (Netherlands: Journal of Geosciences), 84-2, 87-107. 
McMillan, A A and Hamblin, R J O, 2000. A mapping-related lithostratigraphical framework for the Quaternary of the UK, Quaternary Newsletter, 92, 21-34. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable