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): MIDDLE SERIES
Alternative Name(s): none recorded or not applicable
Type Section  An t-Sron headland on east shore of Loch Eriboll, Durness area, north coast of Scotland. 
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, B N, Horne, J, Gunn, W, Clough, C T and Hinxman, L W. 1907. The geological structure of the North-West Highlands of Scotland. Memoirs of the Geological Survey of Great Britain. 
Cowie, J W. 1974. The Cambrian of Spitsbergen and Scotand. 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 & Sons.) Lapworth, C. 1883. The secret of the Highlands. Geological Magazine, Decade 2, Vol. 10, 120-128, 193-199, 337-344. 
Johnson, M R W and Parsons I. 2000. Macgregor and Phemister's geological excursion guide to the Assynt district of Scotland. (Edinburgh Geological Society.) 
Johnston, G S and Mykura, W. 1989. British regional geology: the Northern Highlands (4th edition) (London: HMSO for the British Geological Survey.) 
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.) 
Wright, D T and Knight, I. 1995. A revised chronostratigraphy for the lower Durness Group. Scottish Journal of Geology, Vol. 31, 11-22. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S107 S108 S081 S082 S071 S092 S092 S101 S102 S114