Computer Code: |
DACF |
Preferred Map Code: |
notEntered |
Status Code: |
Index Level |
Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
Lithological Description: |
[Obsolete: use COLA] Composed of micaceous psammite with subordinate semi-pelite, calc-silicate rock and crystalline limestone. Migmatitic gneiss also occurs. |
Definition of Lower Boundary: |
Drawn at base of psammite of Colla Firth Group where it rests conformably on the Weisdale Limestone. |
Definition of Upper Boundary: |
Drawn at conformable upward passage from psammite of the Colla Firth Group to the Girlsta Limestone. |
Thickness: |
About 3500 m thick. |
Geographical Limits: |
Shetlands, Scotland. |
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 |
Colla Firth, Shetlands, Scotland. |
Reference(s): |
Mykura W, 1976 British Regional Geology: Orkney and Shetland (HMSO, Edinburgh).] |
Harris, A L and others, 1973. A correlation of the Pre-Cambrian rocks in the British Isles. Geological Society of London Special Report No 6. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |