Abstract

The structural and petrological changes affecting the Lewisian rocks north of Gairloch during the closing stages of the Laxfordian orogenic episode include deformation that took place under the influence of a changing stress field during conditions of waning metamorphism. There were developed paracrystalline small-scale folds and post-crystalline large-scale folds with associated pseudotachylitic crush veins. Regionally metamorphosed and migmatized sediments and basites were modified and the dominant N.W.-S.E. trend of both lithological bands and foliation was re-orientated to a N.E.-S.W. direction over considerable areas.