The BGS Lexicon of Named Rock Units — Result Details
An T-Sron Formation
| Computer Code: | ASR | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Comley Series (EC) — Comley Series (EC) | ||
| Lithological Description: | Consists of two distinctive members: dolomitic brown-coloured siltstone, mudstone and sandstone (of the Fucoid Beds Member, and white quartzite and quartz arenite of the Salterella Grit Member. | ||
| Definition of Lower Boundary: | Conformably overlies the Pipe Rock Member of the Eriboll Formation. | ||
| Definition of Upper Boundary: | Conformably overlain by dark grey dolostones of the Ghrudaidh Formation of the Durness Group. | ||
| Thickness: | From 20 to 50 m thick. | ||
| Geographical Limits: | The An t-Sron Formation forms a narrow, discontinous belt, extending along the north-western side of Scotland from the Durness-Eriboll area, through Assynt, Dundonnell, Kinlochewe and Kishorn, to Skye. | ||
| Parent Unit: | Ardvreck Group (ARDV) | ||
| Previous Name(s): | Passage or Middle Series [Obsolete Name and Code: Use ASR]
(-1317)
Middle Series [Obsolete Name and Code: Use ASR] (-1316) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | An t-Sron headland on east shore of Loch Eriboll, Durness area, north coast of Scotland. Peach et al., 1907; Prigmore and Rushton, 1999. | ||
| Reference Section | Skiag Bridge Loch Assynt displays a good reference section through the An t-Sron Formation and both its upper and lower boundaries Peach et al., 1907. | ||
| Reference(s): | |||
| Johnson, M R W and Parsons I. 2000. Macgregor and Phemister's geological excursion guide to the Assynt district of Scotland. (Edinburgh Geological Society.) | |||
| Park, E G, Stewart, A D and Wright, D T. 2002. The Hebredean Terrane. 45-80 in the Geology of Scotland. Trewin, N H (Editor). (The Geological Society, London.) | |||
| Phemister, J. 1948. British Regional Geology: Scotland: the Northern Highlands (2nd edition) (Edinburgh: HSMO for the Geological Survey and Museum.) | |||
| Prigmore, J K, and Rushton, A W A. 1999. Scotland: Cambrian and Ordovician of the Hebridean Terrane. 295-315 in British Cambrian to Ordovician Stratigraphy. Rushton, A W A, Owen, A W, Owens, R M and Prigmore, J K (editors). Geological Conservation Review Series. (Joint Nature Conservation Committee.) | |||
| Holland, C H (Editor). Lower Palaeozoic Rocks of the World, Vol.2. (John Wiley & Sons.) | |||
| Cowie, J W. 1974. The Cambrian of Spitsbergen and Scotland. 123-155 in Cambrian of the British Isles, Norden and Spitsbergen, Holland, C H (editor). Lower Palaeozoic Rocks of the World, Vol. 2. (John Wiley and Sons.) | |||
| Johnston, G S and Mykura, W. 1989. British regional geology: the Northern Highlands (4th edition) (London: HMSO for the British Geological Survey.) | |||
| Wright, D T and Knight, I. 1995. A revised chronostratigraphy for the lower Durness Group. Scottish Journal of Geology, Vol. 31, 11-22. | |||
| Peach, B N, Home, J, Gunn, W, Clough, C T and Hinxman, L W, 1907. The Geological Structure of the northwest Highlands of Scotland. Memoir of the Geological Survey of Great Britain. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| S114 S107 S108 S081 S082 S071 S092 S092 S101 S102 | |||