Eriboll
Geological Conservation Review site | GCR #1311 | Structural and Metamorphic Geology | Moine
Scotland's geosites are chosen because of their local, national or international importance. Take only photos, leave only footprints: avoid causing any damage to this site. You can walk almost anywhere in Scotland without the need to ask permission or keep to paths, but you have a responsibility to care for your own safety, to respect people's privacy and peace of mind and to cause no damage.
This site is a Site of Special Scientific Interest (SSSI). It is an offence to intentionally or recklessly damage the protected natural features of a SSSI, and this includes unauthorised sample collection.
The right of access does not extend to quarries, building sites or any land where public access is prohibited, or to the collection of geological samples.
Summary
Historically, the most important location in the Moine Thrust Belt - where the Highlands Controversy was resolved (in 1884), and mylonites were first described (by Lapworth). Excellent accessible and famous thrust structures studied by generations of geologists.
The eastern shores of Loch Eriboll provide the most important and historic section of the entire Moine Thrust Belt - a section which differs from the rest of the Thrust Belt because of the total absence of Torridonian strata. Here the nature and magnitude of tectonic processes and the concept of thrusting were first appreciated, and where the term "thrust" was first coined (as a noun, for the Arnaboll Thrust). The site possesses a wealth of well- exposed, extraordinary tectonic phenomena. Of these, one of the most important is the magnificent coastal exposures of Cambro-Ordovician rocks at Heilam where the significance of imbricate structure and its relationship to the major thrusting were first recognised by Peach & Horne. The Eriboll section inspired a revolution in earth science, ending the Highland Controversy and stimulating new interpretations which have had a seminal influence on the science of tectonics throughout the world. The hillside above Kempie clearly displays the upward transition into mylonites associated with the Moine Thrust.
Site information
Further information
https://www.youtube.com/watch?v=X65-7dfutw0
A short video visit to the Arnaboll Thrust
Related geosites
Overlaps with:
Rob Butler
Looking along the shore of Loch Eriboll, with Ben Arnaboll to the R (east). This is the classic ground mapped by Lapworth which brought the Highlands Controversy to a close.
Rob Butler
The classic outcrop of the Arnaboll thrust - not only where Geikie first coined the term "thrust" but also where Lapworth introduced the World to mylonites.
Rob Butler
Looking across Loch Eriboll to its eastern shore - where the Moine Thrust Belt ("zone of complication" was first discovered!
Rob Butler
Detail of the Arnaboll Thrust, showing mylonitised Lewisian on sheared Pipe Rock. Note the deflected burrows which betray a top WNW shear sense. Outcrops like this demonstrate the clear association of distributed shear to thrust displacement.