| Computer Code: |
USHP |
Preferred Map Code: |
SYMB |
| Status Code: |
Full |
| Age range: |
Tonian Period (AT)
— Tonian Period (AT) |
| Lithological Description: |
Psammite, siliceous and feldspathic, numerous thin gritty to pebbly psammite layers, rare calc-silicate layers. Sparse, thin garnetiferous gneissose pelite layers. Beds 20-100 cm; cross-bedding common; possibly herring bone cross-beds. Near top, interbedded psammite and pelite – transitional into the Laggan Mor Formation. |
| Definition of Lower Boundary: |
Conformably upon the Shiaba Pelite Formation (SAPE). Relatively sharp boundary. |
| Definition of Upper Boundary: |
Conformably overlain by Laggan Mor Formation (LAMO). Transitional boundary: increase in interbedded semipelite beds. |
| Thickness: |
c. 1700 m (estimate - post-deformational thickness). |
| Geographical Limits: |
Ross of Mull, Isle of Mull, Inner Hebrides. |
| Parent Unit: |
Morar Group (MORR)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Coastal section on Ross of Mull, Rubha nam Braihrean to Traigh Bhan na Sgurra [NM 440 181 - NM 424 183]. |
| Reference(s): |
| 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. |
| Krabbendam M, Strachan R A, Prave A. 2021. A new stratigraphic framework for the early Neoproterozoic successions of Scotland. Journal of the Geological Society of London. doi:10.1144/jgs2021-054 |
| Holdsworth, R E, Harris, A L and Roberts, A M, 1987. The stratigraphy, structure and regional significance of the marine rocks of Mull, Argyllshire, west Scotland, Geological Journal, Vol.22, 83-107. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S043
S043
|
