The BGS Lexicon of Named Rock Units — Result Details

Claret Clay Member

Computer Code: CTCL Preferred Map Code: notEntered
Status Code: Full
Age range: Holocene Epoch (QH) — Holocene Epoch (QH)
Lithological Description: Clayey silt and silty clay, finely laminated and crudely stratified with silt and very fine- to medium-, sometimes coarse-grained sand; grey, black and brownish grey, finely micaceous, sulphur-rich, contains shells and shell fragments, and vivianite grains. Massive where bioturbated. These are deposits of an estuarine tidal flat complex formed after the time of highest Holocene sea level (Main Post-Glacial Shoreline).
Definition of Lower Boundary: Unconformable, on older Holocene and late Devensian units including the Bothkennar Gravel Member and the Wilderness Till Formation. Locally the Carse of Stirling Clay Member passes transitionally upwards into the Claret Clay Member in the Alloa-Grangemouth area of the Forth estuary.
Definition of Upper Boundary: Upper boundary mainly at surface or overlain unconformably by modern alluvial deposits, eg, Grangemouth Silt Member.
Thickness: Veneer to perhaps as much as 18m
Geographical Limits: Lower Forth valley from Stirling eastwards to near the Forth estuary in the Falkirk area; area of the estuarine deposits of the Lower Post Glacial Shorelines and associated raised beach surfaces.
Parent Unit: Carse Clay Formation (CARCL)
Previous Name(s): Claret Beds [Obsolete Name and Code: Use CTCL] (-1464)
Alternative Name(s): Carse Clay, Claret Formation
Stratotypes:
Type Section  Bothkennar IGS No.1 Bore, BGS Ref NS98NW/205, 1.3m to 13.9m depth. Browne et al., 1984. 
Reference(s):
Browne, M A E, Graham, D K and Gregory, D M 1984. Quaternary estuarine deposits in the Grangemouth area, Scotland. Report of the Institute of Geological Sciences, No.16/3. 
Peacock, J D. 1998. The Bothkennar Gravel Formation ("buried gravel layer") of the Forth Estuary. Scottish Journal of Geology, Vol.34, 1-5 
Francis, E H, Forsyth, I H, Read, W A and Armstrong, M. 1970. The geology of the Stirling district. Memoir of the Geological Survey of Great Britain, Sheet 39 (Scotland). 
Paul, M A, Peacock, J D and Barras, B F. 1995. Flandrian Stratigraphy and Sedimentation in the Bothkennar-Grangemouth area, Scotland. Quaternary Newsletter, February 1995, No.75, 22-35 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S039 S031