| Computer Code: |
TCDL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Tonian Period (AT)
— Tonian Period (AT) |
| Lithological Description: |
Laminated dark-grey shaley mudstone, siltstone, and very fine- to fine-grained sandstone, with intercalated beds of pale grey fine-grained sandstone that increase in thickness and abundance towards the top of the member. |
| Definition of Lower Boundary: |
Highly variable gradational and/or interdigitating transition from the underlying Fiachanis Gritty Sandstone Member [NM 3730 9366 or NM 3695 9905]. |
| Definition of Upper Boundary: |
Overlain by the Allt Mor Na H-Uamha Mb (TCAM) / Applecross Formation (TCA). The first thickly-bedded (> 2 m), cross-bedded and/or convoluted fine- to medium-grained sandstone bed [NM 4186 9604]. |
| Thickness: |
275m minimum in type-locality (stratigraphical base not visible). |
| Geographical Limits: |
Isle of Rhum, Laimhrig. |
| Parent Unit: |
Diabaig Formation (TCD)
|
| Previous Name(s): |
Bagh Na H-Uamha Shale [Obsolete Name and Code: Use TCDL, TCAM]
(-1221)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Isle of Rum, Laimhrig, [NM 420 970 to NM 418 960]. |
| Reference(s): |
| Emeleus, C H and Bell, B R. 2005. British Regional Geology: the Palaeogene volcanic districts of Scotland (Fourth Edition). (Nottingham: British Geological Survey.) x + 214pp. |
| Krabbendam, M. 2021. A stratigraphic framework for the early Neoproterozoic successions of the Northern Highlands of Scotland. UK Stratigraphic Framework Series. British Geological Survey Open Report, OR/21/072. 86pp. |
| Black, G P, and Welsh, W, 1961. The Torridonian succession of the Isle of Rhum. Geological Magazine, Vol. 98, 265-276. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S060
|
