The BGS Lexicon of Named Rock Units — Result Details

Tayvallich Subgroup

Computer Code: DBTV Preferred Map Code: Tayv
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Dominated by calcitic limestone, in part slumped, resedimented; however, east of mid-Deeside the limestone is replaced by psammite and quartzite with thin beds of calcsilicate rock; lavas, hyaloclastites and graphitic pelites present in Tayvallich area; Banffshire Coast - thick semipelite and calc sequence in upper part.
Definition of Lower Boundary: Bottom of lowest limestone bed in Loch Tay Limestone Formation where present; from Glen Clova to Deeside change from dominant semipelite to psammite or quartzite with calcareous beds.
Definition of Upper Boundary: Top of highest limestone bed in Loch Tay Limestone Formation where present; in Glen Clova and Glen Esk below unit with beds of strongly magnetic semipelite, Banffshire Coast - incoming of dominantly turbiditic psammite and semipelite.
Thickness: Generally 100-250m, but in Aberdeenshire and Banffshire where semipelitic and psammitic lithologies come in, it may reach 2.5km
Geographical Limits: Connemara; North Mayo; Donegal; Newtown Stewart to east of Strabane; Armoy to Torr Head; Kintyre, Tayvallich Peninsula; Loch Awe; from Loch Fyne, via Tyndrum, Loch Tay, Loch Tummel, Glen Shee, Deeside, Donside and Moray Firth coast at Boyne Bay - Whitehills.
Parent Unit: Argyll Group (ARGY)
Previous Name(s): Tayvallich Lavas (-202)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Tayvallich peninsula. (Gower, P J, 1977). 
Reference(s):
Harris, A L and Pitcher, W S, 1975. The Dalradian Supergroup. "In" Harris, A L, Shackleton, R M, Watson, J, Downie, C, Harland, W B and Moorbath, S. A correlation of the Precambrian rocks in the British Isles. Geological Society Special Report, No.6. p.52-75. Scottish Academic Press, Edinburgh. 
Gower, P J, 1977. The Dalradian rocks of the west coast of the Tayvallich peninsula. Scottish Journal of Geology, Volume 13, 125-133. 
Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). 
Harris, A L, Haselock, P J, Kennedy, M J and Mendum, J R, 1994. The Dalradian Supergroup in Scotland, Shetland and Ireland. 33-53 in Gibbons, W E and Harris, A L (editors). A revised correlation of Precambrian rocks in the British Isles. Special Report of the Geological Society, London, No.22. 
Stephenson, D and Gould, D , 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S038 S096 S097 S054 S047 S047 S046 S012 S020 S028 S029 S037 S037 S045 S045 S046 S047 S055 S055 S056 S065 S065 S066 S066 S075 S076 S085 S086 S087 S087 S096 N08 S029