| Computer Code: |
DLI |
Preferred Map Code: |
litho |
| Status Code: |
Full |
| Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
| Lithological Description: |
Dominantly calc-silicate rock, ranging from calcareous psammite to hornblende-zoisite-schist, but containing layers up to 10m thick of fine-grained crystalline limestone with disseminated sulphides. |
| Definition of Lower Boundary: |
Incoming of dominantly calcareous lithologies at the top of the Queen's Hill Formation. This is usually sharp, with only rare calc-silicate layers in the Queen's Hill Formation rocks. |
| Definition of Upper Boundary: |
Change to dominant psammite, often slightly calcareous, with minor layers of calc-silicate rock and semipelite, at base of Tarfside Formation. |
| Thickness: |
Varies from 30m to 100m; probably thickens eastwards from Pollagach Burn to Mains of Midstrath. |
| Geographical Limits: |
Main outcrop is a 100m to 1km strip in the Dee Valley from NO 408945 (Pollagach Burn) to NO 595955 (Mains of Midstrath) (Sheets 65E and 66W). There is also an outcrop area around and to the south east of Banchory (NO 690970 to NO 745928 - Sheet 66E). |
| Parent Unit: |
Tayvallich Subgroup (DBTV)
|
| Previous Name(s): |
Deeside Limestone [Obsolete Code: Use DLI]
(DBDS)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
For calc-silicate rocks: a reasonable section through a significant part of the Formation (with lower boundary at western end) is seen on both banks of the River Dee from Dinnet House to Dinnet Bridge. |
| Type Area |
For limestone: the best exposure of limestones within the Formation are seen in a disused quarry at Mains of Midstrath - numerous pits and small quarries nearby also expose limestone. |
| Reference(s): |
| Read, H H, 1928. The Highland Schists of Middle Deeside and Upper Glen Muick. Transactions of the Royal Society of Edinburgh, Vol.55, p.755-772. |
| Gould, D. 1997. Geology of the area around Alford and Inverurie. Memoir of the British Geological Survey, Sheets 76E and 76W (Scotland). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S065
S066
S076
S066
|
