The BGS Lexicon of Named Rock Units — Result Details

Paisley Clay Member

Computer Code: PAIS Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: The Linwood Borehole (Browne and McMillan, 1989a, Figure 17) is the standard section for the Paisley Clay Member in the Clyde valley west of Govan, and Loch Lomond. Stratigraphical relationships and geographical distribution are in ibid (Figures 2c, 3, 4). The lithofacies are: Clay and silt, finely colour banded in shades of greyish brown and grey; sparse marine fauna (26.5-28.14m in depth). Silt with clay bands, grey, well-bedded; sparse marine microfauna (28.14 - 29.20m). Clay with silt layers, very finely colour laminated in shades of reddish brown and grey (29.20 - 30.23m). Silt with some sand and clay bands; grey, well bedded (30.23 - 31.10m). The succession is thicker and subdivided into three east of Govan. In the Bridgeton Borehole (ibid, Figure 18): Clay, silty, with many silt laminae; colour banded in shades of brownish grey and sometimes reddish brown; rarely fossiliferous (6.9 - 16.23m). Clay, silty, with many silt laminae; colour banded in shades of brownish grey and reddish brown; bands of finely colour laminated clay in shades of reddish brown and grey; rarely fossiliferous (16.23 - 21.77m). Silt with clayey silt and clay bands; thinly laminated to thinly bedded; brownish grey, reddish brown and grey; rarely fossiliferous (21.77 - 29.31m).
Definition of Lower Boundary: The Paisley Clay Member of the Clyde Clay Formation rests with angular unconformity or disconformity on older Quaternary sediments or bedrock. It normally rests on the Wilderness Till Formation of the Caledonia Glacigenic Group (Midland Valley Glacigenic Subgroup). However, under the deeper part of the Quaternary sedimentary basin adjacent to the River Clyde it is underlain by the Bridgeton Sand Member of the Clyde Clay Formation.
Definition of Upper Boundary: The Paisley Clay Member is overlain conformably or unconformably by younger Quaternary sediments. Normally the Linwood Clay Member of the Clyde Clay Formation (of the British Coastal Deposits Group) is in conformable contact but the Clydebank Clay Formation and Clyde Valley Formation of the Britannia Catchments Group (Clyde Catchment Subgroup) is unconformable. It is also extensively exposed at surface in the lower Clyde valley.
Thickness: Veneer to over 25m.
Geographical Limits: The Clyde Clay Formation is recognized in the lower Clyde valley north of Lanark, in and around the estuary of the Clyde and the Firth of Clyde and linked sea lochs, and in Loch Lomond. It is also present under the coastal plain of Ayrshire. The Paisley Clay Member has a distribution similar to the parent formation up to the elevations of 35 to 40m above sea level.
Parent Unit: Clyde Clay Formation (CLYD)
Previous Name(s): Paisley Formation (-4242)
Clyde Beds (-1375)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Geilston Burn, valley side exposures, by Cardross, Clyde Estuary. See also notes on borehole sections within the Lithology description. 
Reference(s):
Forsyth, I H, Hall, I H S and McMillan, A A. 1996. Geology of the Aidrie district. Memoir of the British Geological Survey, Sheet 31W (Scotland). 
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. 
Hall, I H S, Browne, M A E and Forsyth, I H. 1998. Geology of the Glasgow district. Memoir of the British Geological Survey, Sheet 30E (Scotland). 
Jardine, W G (Editor). 1980. Glasgow Region: Field Guide. [Quaternary Reseach Association.] 
Paterson, I B, McAdam, A D and MacPherson, K A T. 1998. Geology of the Hamilton district. Memoir of the British Geological Survey, Sheet 23W (Scotland). 
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