144 



DR. H. HICKS ON THE METAMORrHIC AND 



which the strike of the foliation is beautifully shown : here the 

 gneiss is seen at a height of from 300 to 400 feet above the datum- 

 line ; but it can be traced to a considerably greater height. A fault 

 seems to extend along the glen above referred to ; and the ground 

 is broken up about the entrance. Though the rocks beyond this 

 fault to the KE. of the glen appear to differ in some important par- 

 ticulars from those described on the south side, it is clear, from the 

 notes 2, 3, and 4, that they are also a highly metamorphic series. 

 The fault has probably cut out a considerable thickness of the strata, 

 being, as it is, nearly parallel with the bedding ; therefore there 

 is a rather abrupt passage from the one group to the other. On 

 the south side of the glen, as already stated, the rocks are of the 

 Loch-Maree type ; but those to the north agree better in their peno- 

 logical and physical characters with those of the Ben-Fyn type. I 

 traced the section along the north side as far as Leckie, and found 

 the beds to dip generally at a high angle to the north-east. In 

 some places they are slightly contorted, but are seen quite evenly 

 bedded and in regular succession in the gorge, where the bridge 

 crosses the branch of the river flowing from a glen to join the main 

 stream below Leckie. In the face of the hill on the south side of 

 the main stream of the river and of the valley the beds dip to the S.E. 

 These are much less altered than those described from the north side, 

 and are evidently to be correlated with the flaggy micaceous series 

 in the valley of Glen Docherty to the south. They compose the 

 main portion of the mountain called Craig Roy. At one point they 

 may be seen slightly bent towards the north-east, as if dragged down 

 towards the fault extending along this valley towards Loch Fannich ; 

 but as they are entirely discordant in strike to those on the north side, 

 and dip at a lower angle, it is clear that they are a much newer 

 series, and in their petrological characters may be classed with the 

 flaggy beds which are supposed to be seen in so many areas resting 

 upon the limestone series. After a careful examination of the beds 

 along Glen Logan and its branches, I came to the conclusion that these 

 flaggy beds rest unconformably upon the Loch-Maree and Ben-Fyn 

 series. The faulting has not, in my opinion, been of a character which 

 would so completely baffle the order of succession here as to make 

 this an illusory appearance only ; and the result of the faulting can 

 be calculated without much difficulty. As these beds of Craig Roy 

 approach the western shoulder of Ben Fyn, they appear to dip slightly 

 towards that mountain ; but this also is evidently the result of a 

 fault; for immediately we pass this point eastward, an entirely 

 distinct group of rocks, with a strike from N.W. to S.E., at a very 

 high angle, is met with ; and the beds continue to retain this high 

 dip, with here and there a fold over, through the whole range of 

 mountains east of this point and to the north of Achnasheen. 



3. Neighbourhood of Achnasheen. 



The characteristic gneisses and mica-schists found in these 

 mountains have been described in mv former papers, and in that by 



