The BGS Lexicon of Named Rock Units — Result Details

Tay Catchments Subgroup

Computer Code: TAYCA Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Holocene Epoch (QH)
Lithological Description: A suite of fluvial (river terrace sand and gravel and alluvium) and related lacustrine (silt and clay) and organic (peat) deposits derived from bedrock and glacigenic sediments. Clast rock types of the fluvial sands and gravels include Devonian strata (sandstone, siltstone), volcanic (andesite and basalt) together with intrusive igneous rocks (granite and microdiorite) and metasedimentary rocks of the Grampian Highlands. In the valley of the Tummel and the higher reaches of the Tay, Earn, Almond, Isla, north and south Esk clasts are dominantly of Dalradian metasedimentary rocks and Caledonian intrusive igneous rocks.
Definition of Lower Boundary: Unconformable contact with units of the Mearns, Central Grampian and East Grampians Glacigenic subgroups and bedrock.
Definition of Upper Boundary: Generally the ground surface, but units of the subgroup may be overlain locally by mass movement deposits or may locally interfinger with units of the British Coastal Deposits Group.
Thickness: Up to 25m
Geographical Limits: The present physical catchments of the River Tay and tributaries, the Firth of Tay and the Montrose Basin. The catchments extend across Perthshire and Angus (Strathmore).
Parent Unit: Britannia Catchments Group (BCAT)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  A suite of fluvial (alluvium and river terrace deposits) and associated organic and lacustrine sediments that contain clasts derived from bedrock and glacigenic deposits cropping out in the catchments of the River Tay and other rivers flowing directly to the Firth of Tay, including the rivers Earn, Almond, Tunnel, Isla, and the rivers North Esk and South Esk of Angus. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable