TICINITY OF THE UPPER PAET OP LOCH MAREE. 101 



Game, within a very short distance of the hotel*. The views as to 

 the relations of this series to the other rocks are concisely stated by 

 Dr. Hicks f, in speaking of the Glen-Laggan section, as follows : — 

 " Prof. Nicol places a fault at this point, and says that the funda- 

 mental gneiss is here brought up to give it an appearance of over- 

 lying conformably the unaltered series. I, however, hold, vrith Sir 

 E. Murchison and Mr. Geikie, that the next is a younger series, 

 and that it overlies the unaltered beds ; but I entirely demur to the 

 view held by them that the rocks which compose this group, as exhi- 

 bited here, should be called gneiss rocks, or associated in any way 

 with those which have undergone the metamorphic change so charac- 

 teristic of the pre-Cambrian rocks as known in this country, and which 

 could only be induced, I believe, by influences to which it is evident 

 these rocks, as shown by their position and undisturbed state, could 

 not have been subjected, and which would occur mainly during 

 periods of great depression combined with heat, moisture, and pres- 

 sure. On examination I found these upper beds everywhere unal- 

 tered, except near dykes, and the change there induced in them was 

 that now well known as partial or contact-alteration, and which 

 is so entirely distinct from true or general metamorphism. These 

 beds all dip to the S.E. at a low angle, and attain a thickness of 

 several thousand feet. They are flag-like in character, and are made 

 up chiefly of fragmentary materials, but are occasionally slightly cal- 

 careous. They are much like some of the Lower Silurian flags in 

 Wales, and are in no degree more highly altered than many of those 

 rocks in the more disturbed districts." He goes on to state that, in 

 his opinion, the lower rocks exposed by lateral streams on the north 

 side of Glen Docherty are very unlike those along the hill-side at the 

 higher levels. " They were evidently mueh more allied to the gneiss 

 of the west side of Loch Maree ; and the strike proves to be, as in 

 the latter, from N.W. to S.E., and hence in an entirely opposite di- 

 rection to that in the higher beds These gneiss rocks keep 



at a low horizon for about four miles, or until we reach the top of 

 the Glyn. At this place they assume a reddish granitoid appearance, 

 and ascend considerably higher into the hill. Por the next few miles 

 they are traced with more difficulty, and probably faulted, but rise 

 up again into the mountains as we approach Auchnasheen. The 

 upper or overlying beds are entirely lost at the ravine which sepa- 

 rates these hiUs from Ben Fyn and the range of mountains behind 

 Auchnasheen." 



One difficulty, inherent in this view, cannot, I think, fail to strike 

 the observer as soon as he has become familiar with the district. It 

 is the disappearance in so short a space ofthe entire thickness of the 

 Torridon Sandstone and the quartzites, not to mention the overlying 

 calcareous series. These, at the southern end of Loch Maree, can 



* Here the dip is 8° to S.S.E. ; about ^ of a mile higher up the stream 26° 

 to S. The Glen-Laggan fault is prolonged up Glen Garrie, the quartzite still 

 plunging towards it, but its throw is diminished. It is remarkable in this 

 district how closely the streams follow the faults. 



t Q. J. G. S. vol. xxxiv. p. 814. 



