Computer Code: |
DA |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
Lithological Description: |
[Obsolete: use APP] Relatively thin formations of limestone, commonly carbonaceous pelite, quartzite and characteristic striped and laminated pelite-psammite basal quartzites and semi-pelites. |
Definition of Lower Boundary: |
Drawn at base of interbanded quartzites and semi-pelites possibly belonging to the Lochaber Sub-Group, where it rests conformably on sandstones of the Grampian Group. |
Definition of Upper Boundary: |
Drawn at conformable upward passage from limestone intepreted to be of the Blair Atholl Sub-Group to tillite interpreted to be of the Islay Sub-Group. |
Thickness: |
Not known. |
Geographical Limits: |
Shetland, Grampian, Highland, Tayside, Central, Strathclyde, Inner Hebrides, Scotland. Donegal, Mayo, Connemara, Ireland. |
Parent Unit: |
none recorded or not applicable
|
Previous Name(s): |
Lower Dalradian Group (Now Appin Group) [Obsolete Name and Code: Use DA]
(-182)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
Appin area, Strathclyde, Scotland. |
Reference(s): |
Wilson, H E. 1972. The regional geology of Northern Ireland. (Belfast: HMSO for Geological Survey of Northern Ireland.) 113pp. |
Rast, N and Litherland, M, 1970. The correlation of the Ballachulish and Perthshire (Iltay) Dalradian successions. Geological Magazine, Vol.107, p.259-272. |
Hickman, A H, 1983. Geochemistry and chemostratigraphical correlation of slates, marbles and quartzites of the Appin Group, Argyll, Scotland. Transactions of the Royal Society of Edinburgh, Vol.73, p.251-278. |
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. |
Anderson, J G C. 1948. Stratigraphic nomenclature of Scottish metamorphic rocks. Geological Magazine, Vol. 85, 89-96. |
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. |
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 |