The BGS Lexicon of Named Rock Units — Result Details

Middle Dalradian Group [Obsolete: use ARGY]

Computer Code: DB Preferred Map Code: notEntered
Status Code: Index Level
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: [Obsolete: use ARGY] Well differentiated quartzite and thinly bedded pelite - basal tillite.
Definition of Lower Boundary: Drawn at base of tillite of the Islay Subgroup where it rests conformably on limestone interpreted to belong to the Blair Atholl Sub-Group.
Definition of Upper Boundary: Drawn at conformable upward passage from limestone interpreteted to belong to the Tayvallich Sub-Group to semi-pelitic and psammitic wacke of the Southern Highland Group.
Thickness: Not known.
Geographical Limits: Shetland, Grampian, Tayside, Central Strathclyde, Inner Hebrides, Scotland. Connemara, Mayo, Antrim, Donegal, Ireland.
Parent Unit: none recorded or not applicable
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Argyll district, Strathclyde, Scotland. 
Reference(s):
Johnson, M R W, 1983. Dalradian. "In" Craig, G Y. Geology of Scotland, Edinburgh. 
Rast, N, 1963. Structure and metamorphism of the Dalradian rocks of Scotland. "In" Johnson, M R W and Stewart, F H, (Editors). The British Caledonides, Edinburgh, p.123-142. 
Knill, J L, 1963. A sedimentary history of the Dalradian Series. "In" Johnson, M R W and Stewart, F H, (Editors). The British Caledonides, p.99-121. 
Anderson, J G C. 1948. Stratigraphic nomenclature of Scottish metamorphic rocks. Geological Magazine, Vol. 85, 89-96. 
Wilson, H E. 1972. The regional geology of Northern Ireland. (Belfast: HMSO for Geological Survey of Northern Ireland.) 113pp. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable