ARRAN. GEOLOGY. SCHIST. 355 



waters of Ransa and Catcol, as well as those of the lorsa, 

 to a considerable distance, until it is superseded by the 

 granite. Although the regions where the one rock ends 

 and the other commences, can generally be determined 

 within a certain limit, the actual junctions are rarely 

 visible, owing to the incumbrance of soil and plants. In, 

 very dry seasons, and with care, some of these points 

 might possibly be found in those torrents where the rock 

 is laid bare : but even in these places, the view is often 

 obstructed by the blocks of granite which accumulate 

 in the beds of the streams and conceal the junctions. The 

 actual junction is however visible near Loch Ransa, but 

 it was already mentioned in speaking of the granite. I 

 shall here only add that it extends from Tor nion, where it 

 has been laid bare, across the opposite ridge into Glen 

 Catcol ; during the whole of which course it is occasionally 

 visible. 



The position of the beds of schist with respect to the 

 granite, can also be determined with certainty in many 

 parts of this junction, and they may in general be said 

 to recline against it : yet if, in other cases, a given bed of 

 schist be prolonged towards that rock, according to its 

 position in any one place, it will be^ found to indicate 

 the contact of the edges instead of the faces ; while, in 

 tracing the linear direction of the strata in a third set, 

 they will tend to abut endwise against the mass of granite. 

 But as ,in examining the positions of the schistose beds in 

 various places, they are found to be discordant and irre- 

 gular with regard to each other, no general rule respecting 

 their prolongation or mutual relation can be established ; 

 and it is therefore equally impossible to assign their rela- 

 tions to the granite in a more accurate manner. No 

 general conclusion can therefore be drawn with respect 

 to this connexion, from the appearances any where ob- 

 served; since even the slight kind of conformity visible 

 at one point of junction, may not be continued perhaps 



