| Computer Code: |
MAMS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Tonian Period (AT)
— Tonian Period (AT) |
| Lithological Description: |
Dominant pelitic to semipelitic beds. In places massive, elsewhere clearly interbedded. Locally three different units can be recognised: (i) interbedded pelite, semipelite and psammite with calc-silicate; (ii) schistose pelite with subordinate semipelite layers; (iii) laminated semipelite and micaceous psammite, with thin siliceous psammite and calc-silicate layers. |
| Definition of Lower Boundary: |
Conformably upon the Lower Morar Psammite Formation (MALP). Relatively sharp boundary. |
| Definition of Upper Boundary: |
Conformably overlain by the Upper Morar Psammite Formation (MAUP). |
| Thickness: |
c. 100 - 1000m; highly variable due to deformation. |
| Geographical Limits: |
NW Highlands: Ardnamurchan, Morar, Knoydart, Kintail. |
| Parent Unit: |
Morar Group (MORR)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Ramsay, J.G. and Spring, J., 1962. Moine stratigraphy in the Western Highlands of Scotland. Proceedings of the Geological Association, 73: 295-326. |
| 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. |
| Johnstone, G S, Smith, D I, and Harris, A L. 1969. The Moinian Assemblage of Scotland. In: Kay, M. (editor). North Atlantic Geology and Continental Drift: A Symposium. Memoirs of the American Association of Petroleum Geologists, Vol. 12, 159-180. |
| Bonsor H C, and Prave A R. 2008. The Upper Morar Psammite of the Moine Supergroup, Ardnamurchan Peninsula, Scotland: depositional setting, tectonic implications. Scottish Journal of Geology 44, 1-12. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S071
S061
S061
S062
|
