Discussion

Abstract

Dr. J. V. W atson commented on the author's evidence that the rocks of adjacent regions had behaved differently in response to Laxfordian regeneration. Dr Park had confirmed Clough's view that the south-western limb of the Tollie antiform had been much more severely deformed than the north-eastern limb during the formation of the antiform. He had found that Laxfordian folds and fabrics of an earlier generation were also poorly developed in parts of the north-eastern limb, where Scourie dykes were not only discordant but also retained remnants of igneous minerals and textures. It therefore seemed that a contrast had been established at an early stage in Laxfordian regeneration between the north-eastern block, bordering Loch Maree, which was destined to remain relatively unaffected through successive episodes and the remainder of the region which was destined to be repeatedly deformed. Such a differentiation of active and inactive zones, initiated at an early stage and maintained through several phases of reworking, seemed to be rather characteristic of the Lewisian complex as a whole. T he A uthor , in reply to Dr Watson, agreed that the north-eastern and south-western halves of the Tollie area had behaved differently during the Laxfordian deformation and metamorphism, and that these differences had been initiated at an early stage. Although the pre-dyke history of the south-western limb was difficult to unravel, the differences between the central part of the area (sub-area 1) and the north-eastern part (sub-area 4) were probably initiated even before the intrusion of the dykes. Dr R. S t J.