Basement-cover relationships at Lewisian inliers in the Moine rocks

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Abstract
Summary: Lewisian basement of the N Highlands occurs (a) as an autochthonous massif, the Strathy Complex, (b) in parautochthonous fold cores, e.g. Morar, and (c) as slices along zones of high strain, e.g. the Sgurr Beag Slide. Structural features, within the Morar Division psammites adjacent to the Glenfinnan Division and to Lewisian inliers, have been used to define zones of increasing strain within some of which Lewisian strips now occur. The psammites show evidence of high strain where slides occur and massive, cross-bedded psammites give way to thinly banded platey psammites with a total absence of sedimentary structures. Folds progressively tighten. Quartz veins are re-orientated into parallelism with the foliation in the psammite and discordant fabrics are lost. In contrast to psammites at slides, those adjacent to Lewisian rocks in parautochthonous fold cores show only some of these features and those adjacent to the autochthonous massif show none of these features.