Torridonian and Lewisian rocks lying in inverted order between the Kishorn thrust and the Moine thrust, and Moine rocks, lying above the Moine thrust, exhibit a remarkable parallelism of structure.

New evidence shows that three sets of minor structures have been developed in the formations during the Caledonian movements. At least two of these sets pre-date the Moine thrust movements. The mylonites, which are not restricted to the vicinity of the Moine thrust outcrop, belong to an earlier movement phase than these structures and are not directly related to the clean-cut thrust movements. They appear to represent narrow zones of shearing and sliding, mainly within the Lewisian gneisses that developed early in the Caledonian orogeny.

There is reason to suppose that the inversion of the rocks to the west of the Moine thrust occurred before the formation of the minor structures recognized in the paper.

The minor structures are described and their order of formation established. The plastic, para-crystalline style of the earlier deformation is contrasted with the post-crystalline brittle style of the later deformations.