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DR. H. HICKS OK THE METAMORPHIC AKD 



been supposed, the strike in the crystalline schists being about 

 due north and south, whilst in the unaltered rocks it is from north- 

 east to south-west. At Loch Kishorn, much further to the west, 

 the same limestone is thrust in among the schistose series by faults; 

 whilst in the Loch-Alsh promontory the whole of the limestone and 

 most of the quartz rocks have been cut off by faults, and beds belonging 

 to the Torridon Sandstone series have been brought against and 

 apparently made to dip under schists identical with those immediately 

 in contact with the Loch-Kishorn limestone. The evidence there- 

 fore of great dislocations of the strata along these lines is most 

 marked, and it is along these broken lines that the so-called gradual 

 passage from unaltered to highly crystalline strata has been supposed 

 to be seen. With the exception of the flat-bedded series found on 

 either side of Glen Docherty there is scarcely any evidence whatever 

 in these areas of the presence of rocks which can be classified as 

 newer than the Limestone series. The least altered of those which 

 are included in this paper in groups older than the Torridon Sandstone 

 are more highly crystalline than are the majority of the Pebidian 

 rocks of Wales, or of the Huronian rocks of Canada, each of these 

 being undoubtedly of Archaean age. And by very far the largest 

 proportion are equally crystalline with those found in the western 

 series where overlain by Torridon Sandstone and also with the rocks 

 characteristic of the groups found in the Hebrides. Were we also 

 to exclude from consideration those which do not show an intimately 

 crystalline condition, the chief conclusions arrived at would be still 

 the same. There are clear indications in the so-called eastern as 

 well as in the western area of several well-marked series in the 

 schists. The main groups recognizable along the north-west coasts 

 can be made out with equal clearness in the central areas. The same 

 types are found to succeed one another ; the same segregation-veins 

 of hornblende, of quartz and pink felspar, and of black mica, and the 

 same disseminated minerals which are in any way found to be cha- 

 racteristic of groups along the west coast are found equally abundantly 

 in the schists of the so-called eastern areas. The most massive and 

 most highly crystalline of the so-called eastern rocks are found towards 

 the base of the series and in the most central portions of the area, and 

 the more evenly bedded ones thrown off in broken folds towards the 

 east and west. This interpretation, as explained in describing fig. 4, 

 entirely reverses the order given by Sir R. Murchison and Prof. 

 Geikie, who have maintained that the most highly crystalline rocks 

 occur in a great synclinal trough supported by the fossiliferous 

 quartzose series. The idea that the so-called eastern rocks retain 

 a more regularly bedded appearance throughout than is usual in 

 Archaean rocks is not borne out by examination. That a very- 

 regular stratification is well marked in a considerable proportion 

 of these gneisses is perfectly true ; but that the same may be said 

 of a large proportion of the gneisses in the so-called western areas 

 is equally true : similar evenly bedded gneisses, it is well known, are 

 abundantly present also in the Laurentian rocks of Canada. Such 

 a high state of crystallization as is found throughout in the evenly 



