Abstract

Dr. A. J. Barber remarked on the similarity between the Lewisianoid rocks described in the paper and Lewisian rocks of eastern Glenelg and north-east of Loch Duich. Eclogite, common in these areas, appeared to be absent from the Lewisianoid masses. A careful search of hornblendic rocks might show that some of them contained relic eclogitic minerals and textures. Dr. Barber went on to ask if any rocks corresponding to the Lewisian of western Glenelg could be recognised in the Lewisianoid masses. Finally, had Dr. Simony found any structural evidence of downward closure of isoclinal folds cored by Lewisianoid rocks as illustrated in his cross section?

Mr. G. S. Johnstone stated that the Highland Unit of I.G.S. had re-examined part of Dr. Simony's area as part of the progressive mapping programme on the Cluanie sheet. They had the advantage of a certain amount of previous work by the late C. T. Clough and also knowledge of the general content of Dr. Simony's thesis. In addition work was being carried out in the Coire nan Gall area to the north in ground which has considerable affinities with that of Dr. Simony. While in general agreement with his maps and structural sequence, the I.G.S. position differs significantly from that of the author on two points.

Dr. Simony suggests that in the Bealach a' Chasain-Saddle area the Lewisianoid rocks occupy the cores of downward facing folds rooting to the north-west. Dr. Berridge of I.G.S. considers that the main Lewisianoid strip is less continuous than

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