Computer Code: |
TASP |
Preferred Map Code: |
TASP |
Status Code: |
Full |
Age range: |
Stenian Period (AI)
— Stenian Period (AI) |
Lithological Description: |
Red to black mudstone. Lower half is interbedded, with thin beds of siltstone, fine sandstone and rare limestone. Upper half is entirely massive mudstone. |
Definition of Lower Boundary: |
Conformably overlies the Stac Fada Member (TASF). Marked by incoming of first red mudstone. Locally directly overlying the Lewisian Gneiss (L) on palaeo-highs (e.g. Enard Bay). |
Definition of Upper Boundary: |
Conformably overlain by the Meall Dearg Formation (TAD). Incoming of red sandstone, with erosive base. |
Thickness: |
100 m (maximum - thins south of Stoer). |
Geographical Limits: |
Occurs on several headlands in the NW Highlands, east of the Coigach Fault, and west of the Moine Thrust. |
Parent Unit: |
Bay of Stoer Formation (TAS)
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Previous Name(s): |
none recorded or not applicable
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Alternative Name(s): |
none recorded or not applicable
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Stratotypes: |
Type Section |
Coastal section (tidal!) c. 800 m west of Stoer Village, just west of 'Stac Fada' headland; 300 m east of Rubh' a' Mhill Dheirg |
Reference Section |
Coast section at Camas a' Bhothain, Enard Bay. |
Reference(s): |
Gracie, A.J. and Stewart, A.D., 1967. Torridonian sediments at Enard Bay, Ross-shire. Scottish Journal of Geology, 3: 181-194. |
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. |
Parnell, J., Mark, D., Fallick, T.E., Boyce, A. and Thackrey, S., 2011. The age of the Mesoproterozoic Stoer Group sedimentary and impact deposits, NW Scotland. Journal of the Geological Society of London, 168: 349 - 358. |
Stewart, A D. 2002. The later Proterozoic Torridonian rocks of Scotland: their sedimentology, geochemistry and origin. Geological Society Memoir. Vol. 24. (The Geological Society.) |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
S107
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