The BGS Lexicon of Named Rock Units — Result Details

Inverleven Gravel Member

Computer Code: INVN Preferred Map Code: INVN
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: The typical lithology is angular to subrounded boulders, cobbles, gravel and pebbles in a clayey sand matrix. The clasts appear to have had barnacles growing on them although no in-situ examples were retrieved. The formation also contains intact, faded, life-coloured shells of the scallop Chlamys islandica. The shells are not significantly abraded.
Definition of Lower Boundary: The Inverleven Gravel Member of the Clyde Clay Formation rests with angular unconformity on older Quaternary sediments or on bedrock. Most comonly it rests on the Paisley Clay Member of the Clyde Clay Formation or on the Wilderness Till Formation (WITI) of the Caledonia Glacigenic Group (Midland Valley Glacigenic Subgroup).
Definition of Upper Boundary: The Interleven Gravel Member of the Clyde Clay Formation is overlain conformably or disconformably by younger Quaternary sediments, commonly either the Balloch Clay Member of the Clyde Clay Formation or the Clydebank Clay Formation of the British Coastal Deposits Group. It is not exposed at the surface.
Thickness: Veneer to more than 3m
Geographical Limits: The Interleven Gravel Member of the Clyde Clay Formation is recognised in the lower Clyde valley from east of Erskine Bridge westwards to the estuary of the Clyde, and in the Leven valley south of Loch Lomond.
Parent Unit: Clyde Clay Formation (CLYD)
Previous Name(s): Inverleven Formation (-1613)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Leven valley, south of Loch Lomond. Browne and McMillan, 1989a. 
Type Section  Named from BGS Inverleven Borehole at Dumbarton, which contains the standard section (54.0 to 54.8m depth). 
Reference(s):
Browne, M A E and McMillan, A A. 1989a. Quaternary geology of the Clyde valley. British Geological Survey Research Report, SA/89/1. 
Browne, M A E and McMillan, A A. 1989b. Geology for land use planning: drift deposits of the Clyde valley Volume 1: Planning Report. British Geological Survey Technical Report, WA/89/78. 
Jardine, W G (Editor). 1980. Glasgow Region: Field Guide. [Quaternary Reseach Association.] 
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. 
Bowen, D Q. 1999. A revised correlation of Quaternary 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