Abstract
The Lewisian-like rocks occur in the Moines in three zones as sheets up to 150 m thick and intimately interlayered with Moine schists and psammites. They include metagabbro, amphibolite, migmatite, marble and laminated hornblende schist, the latter occurring mainly at the margins of the bodies and is a tectonite derived from the other rock types during the interlayering within the Moines. The Lewisian sheets are demonstrated to be pieces of the pre Moinian basement tectonically emplaced within the Moine cover during the first of three phases of folding which affected the area. Two northerly zones areinterpreted as the cores of fold nappes having roots to the northwest of the area while the southerly zone is at the base of a thrust sheet, and marks the continuation of the Sgurr Beag slide in The Saddle area.