The Moine Thrust Zone


Beinn Aird da Loch

View of the thrust front at Beinn Aird da Loch with basement gneiss thrusted onto younger metasedimentary rocks along the Glencoul Thrust (see cross-section).

Geological Period

Archaean – Devonian

Main geological interest

History of geosciences
Igneous and metamorphic petrology


North West Highlands Geopark, Scotland, UK.
58°02’02.0″N, 5°04’16.0″W

View of the thrust front at Beinn Aird da Loch with basement gneiss thrusted onto younger metasedimentary rocks along the Glencoul Thrust (see cross-section).

The classic orogenic front of significant importance in both modern and historical tectonics research.

Debate on the origins of mountain belts raged in the 19th and early 20th centuries (e.g. Lapworth, 1885). An emerging recognition of thrust tectonics marked a monumental shift in understanding how our planet works, ultimately leading to the establishment of the theory of plate tectonics (e.g. Dewey and Kidd, 1974). The Moine Thrust Zone is a key locality enabling this transition, and many fundamental concepts in structural geology, such as mylonites (Lapworth, 1885), were established there. Its excellent exposure and the beautiful Scottish Highlands setting continue to attract students, professionals and amateur geologists.

Close-up of the thrust plane, exposed near the geological trail at Knockan Crag Visitor Centre.

The Moine Thrust Zone in NW Scotland is over 200 km long, extending from Tongue area in the north to the Sleat Peninsula on the Isle of Skye (Murchison and Geikie, 1862; Peach et al., 1907; Law et al., 2010). The thrust zone is one of the best exposed orogenic fronts in the world, representing a geological history of >2 billion years. The Precambrian basement gneiss (up to c 3.0 Ga) are unconformably overlain by Meso- to Neoproterozoic (c. 900-1000 Ma) sandstone and conglomerate; these are in turn overlain by Cambro-Ordovician (c. 500 Ma) sandstone, shale and limestone. During the Silurian (c. 320 Ma), the Scandian phase of the Caledonian Orogeny thrusted the Precambrian gneiss onto the younger sedimentary rocks. This entire package is in turn overthrusted by the Neoproterozoic metasedimentary rocks of the Moine Supergroup. The thrust zone geometry and the deformation within the foreland sediments is very variable in 3D, ranging from single thrust surfaces to networks of splays, including up to 100 m-scale imbricate packages. Much of the thrust zone is within the NW Highlands Geopark, easily accessible at the Knockan Crag visitor centre, with other good viewpoints e.g. around Loch Glencoul, Kylesku.

Research along the Moine Thrust Zone was sparked by 19th century debates on the origins of mountain belts, culminating in the seminal publication of Peach et al. (1907). The variety of structures along the thrust zone continues to inspire research, exemplified by Law et al. (2010).

Cross section along Loch Glencoul, published in the original 1923 Assynt District geological map.

Dewey, J.F. and Kidd, W.S.F. (1974) ‘Continental Collisions in the Appalachian-Caledonian Orogenic Belt: Variations Related to Complete and Incomplete Suturing’, Geology, 2(11), pp. 543–546. Available at:<543:CCITAO>2.0.CO;2.

Lapworth, C. (1885) ‘The Highland Controversy in British Geology’, Nature, 32, pp. 558–559.

Law, R. et al. (2010) Continental Tectonics and Mountain Building: The Legacy of Peach and Horne, Geological Society London Special Publications. Available at:

Murchison, S.R.I. and Geikie, S.A. (1862) First Sketch of a New Geological Map of Scotland with Explanatory Notes. Edinburgh: W. & A.K. Johnston, and W. Blackwood & Sons.

Peach, B.N. et al. (1907) The Geological Structure of the NW Highlands of Scotland. Glasgow: HMSO (Memoirs of the Geological Survey of Great Britain).

Peach, B.N. et al. (1923) Assynt District Map Sheet. Geological Survey of Scotland.

Taija Torvela
University of Leeds, United Kingdom

David Peacock
University of Göttingen, Germany