The BGS Lexicon of Named Rock Units — Result Details
Arnisdale Psammite Member
| Computer Code: | MAAP | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Tonian Period (AT) — Tonian Period (AT) | ||
| Lithological Description: | Typically buff to pink fine-grained massive thick-bedded (>1 m) but fine grained psammite. Typically brown to orange-brown. Commonly strongly recrystallised: sedimentary structures are rare and ill-defined and any intrabed laminations are typically wispy. | ||
| Definition of Lower Boundary: | Conformably upon the Basal Pelite Formation (MABP) or unconformable typically of the Western Glenelg Gneiss (WGG); unconformity normally highly sheared. | ||
| Definition of Upper Boundary: | Conformably overlain by the Rubha Ruadh Semipelite Member (MARRS); transitional contact of interbedded psammite and semipelite, indicating a broad fining upwards trend. | ||
| Thickness: | c. 1000 m (estimate; unit is deformed). | ||
| Geographical Limits: | NW Highlands: Morar, Knoydart, Kintail. It is currently not known how far to the NE the unit can be traced into Glenshiel and Kintail. It is also uncertain whether the Morar Group psammite near Glenelg are part of the Arnisdale Psammite Member (c.f. Ramsay and Spring, 1962). | ||
| Parent Unit: | Lower Morar Psammite Formation (MALP) | ||
| Previous Name(s): | Armisdale Psammite
(-5240)
Main Striped Group (-5241) |
||
| 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. | |||
| Richey, J.E. and Kennedy, W.Q., 1939. The Moine and sub-Moine series of Morar, Inverness-shire. Bulletin of the Geological Survey, Great Britain, 2: 26-45. | |||
| Peach, B N, Horne, J, Woodward, H B, Clough, C T, Harker, A and Wedd, C B. 1910. The geology of Glenelg, Lochalsh and the south-east part of Skye (Explanation of One-Inch Map 71). Memoir (Sheet) of the Geological Survey of Great Britain (Scotland). (Edinburgh: His Majesty's Stationery Office.) 206pp. | |||
| 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, Leslie, A, and Goodenough, K. 2014. Structure and stratigraphy of the Morar Group in Knoydart, NW Highlands: implications for the history of the Moine Nappe and stratigraphic links between the Moine and Torridonian successions. Scottish Journal of Geology, Vol. 50, 125-142. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S071 | |||