Moine geology in South and Central Sutherland - an excursion

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From: Strachan, Rob, Friend, Clark, Alsop, Ian, Miller, Suzanne (Editors). A Geological excursion guide to the Moine geology of the Northern Highlands of Scotland.: Edinburgh Geological Society, Glasgow Geological Society in association with NMS Enterprises, 2010.

By Rob Strachan, Bob Holdsworth, Maarten Krabbendam, Graham Leslie and Jack Soper

Fig. 10.1 Simplified geology of south and central Sutherland together with the localities for the excursion.

Excursion 10 South and Central Sutherland is composed of the following articles:[edit]

Excursion 10 South and Central Sutherland[edit]

Purpose: To examine various phenomena within the Moine, including basement-cover relationships, Caledonian ductile thrusts, migmatites, and minor syn-tectonic igneous intrusions.
Aspects covered: Lewisianoid basement inliers; metasedimentary rocks and structures of the Morar and Glenfinnan groups; Sgurr Beag and Naver thrusts; Naver Nappe migmatites; the Vagastie Bridge Granite.
Useful information: Hotel and B&B accommodation are available in Lairg and Bonar Bridge (camping is also available in Lairg). Vehicular access to Locality 10.2 requires permission from Alan Wyatt, Caplich Estate (Tel: 01549 441356). Permission to access the Airde of Shin should be sought from Mrs Parrot, The Croft House, West Shinness, Lairg, IV27 4DN (Tel: 01549 402095).
Maps: OS: 1:25,000 sheets 443 Ben Klibreck and Ben Armine, 440 Glen Cassley and Glen Oykell, 438 Dornoch and Tain; BGS: 1:50,000 sheets 93E Alness, 102E Loch Shin, 108E Loch Naver.
Type of terrain: Stream sections, moorland, lochside and coastal exposures.
Distance and time: The complete excursion involves driving some 180km, assuming overnight accommodation in either Lairg or Bonar Bridge. The total distance covered on foot is c.28km. 2½ days should be allowed for the whole excursion. See each locality for suggested times.
Short itinerary: A shorter excursion could include Locality 10.1 and then either Locality 10.3 or 10.4. Locality 10.5 could be visited en route to North Sutherland if travelling from Lairg.

The large and often remote tract of ground that forms south and central Sutherland (Fig. 10.1) is generally poorly exposed, but forms a critical link between the hitherto better-known areas of northern Ross-shire and north Sutherland. Recent remapping of some of this ground, partly in association with the production of revised British Geological Survey maps, has drawn attention to this area which contains some key sections for demonstrating the nature of basement-cover relationships as well as the existence of regional-scale Caledonian ductile thrusts (Strachan & Holdsworth, 1988).

References[edit]

At all times follow: The Scottish Access Codeand Code of conduct for geological field work