STRUCTURES IN THE CALEDONIDES BETWEEN LOCH DUICH AND GLENELG, NORTH-WEST HIGHLANDS

Abstract

At least three periods of folding affected the Moine and Lewisian rocks south of Loch Duich in the North-West Highlands before the formation of the Moine thrust. Two major folds are recognized and shown to belong to a set recognized elsewhere. The folding is frequently markedly disharmonic and is accompanied by sliding. The small-scale structures are described and figured. It is shown that the intensity of the regional metamorphism and related phenomena diminished during the folding. The changes in structural style resulting from this are described. A system of quartz-filled gashes in the Torridonian west of the Moine thrust is shown to be related to the Loch Alsh fold. Conjugate folds and other structures formed with the Moine thrust, are shown to be later than any of the large folds affecting the Moines.