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Kinloch Laggan Road

Geological Conservation Review site | GCR #854 | Structural and Metamorphic Geology | Dalradian

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 collecting geological samples. For further information, see https://www.scottishgeologytrust.org/geology/geological-sample-collecting/

Summary

The Kinloch Laggan Road GCR Site contains the type locality for the Kinlochlaggan Boulder Bed, which represents one of a number of boulder beds containing extrabasinal clasts within the Dalradian succession. The boulder bed occurs within a conformable stratigraphical succession that can be correlated with the Lochaber Subgroup of the Appin Group. It lies beneath a significant intra-Appin Group unconformity in the local succession where the upper parts of the Lochaber and lower parts of the Ballachulish Subgroup are absent. The clasts of extrabasinal granite, together with quartzite, semipelite, pelite and feldspar at Kinlochlaggan are interpreted to have been ice-rafted and therefore indicate a glacial influence. The site is of national importance in demonstrating the earliest recorded glacial influence within the Dalradian. When combined with the Port Askaig Tillite and the boulder beds in the upper parts of the Dalradian, it demonstrates a repeated glacial influence during Neoproterozoic and Early Palaeozoic times.

Daniel Burgess

Nov. 4, 2023

NN 5475 8971

The roche moutonnée at Cromra - type locality for the Kinlochlaggan Quartzite Formation.