| Computer Code: |
DBCN |
Preferred Map Code: |
Crin |
| Status Code: |
Full |
| Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
| Lithological Description: |
Coarse-grained quartzite present in Argyll at base of subgroup; upper part of subgroup in Argyll and whole of subgroup elsewhere formed of interbedded semipelite and pelite with minor psammite - this facies denotes the commencement of deep-water turbiditic sedimentation. Gritty psammite and semipelite near top in Glen Dochart - Kikin. |
| Definition of Lower Boundary: |
Incoming of coarse pebbly quartzite or psammite at base of Crinan Grit or Upper Erins Quartzite (Argyll); change from calcareous pelite or volcaniclastic rocks to non-calcareous turbiditic semipelite, pelite and psammite (Perthshire to Banffshire). |
| Definition of Upper 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. |
| Thickness: |
1.5-3km |
| Geographical Limits: |
Connemara; North Mayo; Donegal; Newtown Stewart to east of Strabane; Armoy to Torr Head; Kintyre, Knapdale; Crinan to Loch Awe; from Loch Fyne, via Tyndrum, Loch Tay, Loch Tummel, Glen Shee, Deeside, Donside and Ladder Hills to the coast from Aberdeen to Ellon, Peterhead to Fraserburgh, and Portsay to Boyne Bay. |
| Parent Unit: |
Argyll Group (ARGY)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Knapdale and mid-Argyll. (Roberts, J L, 1977). |
| Reference(s): |
| 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. |
| 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. |
| Treagus, J E. 2001. Solid geology of the Schiehallion district. Memoir of the British Geological Survey, Sheet 55W (Scotland). |
| Roberts, J L, 1977. The Dalradian rocks of Knapdale and North Kintyre. Scottish Journal of Geology, Vol.13, 113-124. |
| 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: |
|
S012
S020
S028
S029
S037
S037
S045
S045
S046
S047
S054
S055
S055
S056
S065
S065
S066
S066
S075
S076
S085
S086
S087
S087
S096
S097
N08
S029
S019
S036
S067
S038
S096
S086
S046
S047
S047
|
