The Breadalbane Mines. 191 



is traversed by a line of fault, with a ISr.E. and S.W. trend, 

 which roughly divides it into two portions. The part 

 on the west side of the fault consists of hard, massive, 

 slightly ferruginous quartzites, with lenticular beds of 

 mica schist; while the less hilly country on the east side 

 is almost entirely composed of the hydromica schist so 

 abundant in this part of the Highland area. The section in 

 Fig. 1 is drawn along the course of the AUt nan Sae, a stream 

 which crosses the strike of the beds as it flows south-east- 

 wards down the slope of the Meall Odhar towards the 

 Coninish river. The Meall Odhar (2046 feet high) forms the 

 central part of a ridge which trends eastwards towards 

 Clifton, ending in the Sron nan Golan, in which the mines 

 are situated. Immediately to the west of the Meall Odhar 

 there is a col, on the other side of which the ground rises in 

 Beinn Chuirn to a rugged mountain peak, which looks down 

 on the Coninish valley from an altitude of 2878 feet. 



The schists (Fig. 1) which form the eastern part of the 

 ridge are well exposed along the bed of the AUt nan Sae for 

 a distance of half a mile upwards from its mouth. A steadily 

 descending section of greenish and silvery grey hydromica 

 schist is there passed over. The dip, as the arrows on the 

 map indicate, is to S. and S.S.E., and increases from 20° or 25° 

 at the foot of the hill to 50° at the point where the fault 

 crosses the stream. A felsite dyke traverses the schists a 

 short distance below the fault, and still farther down in the 

 stream section we have observed a bed of hornblende schist 

 containing magnetic pyrites. The schists are veined with 

 white quartz, which increases in quantity towards the fault. 



Forming a series of picturesque cascades, over which the 

 burn rushes, the quartzites make their appearance at the foot 

 of the falls, where they abut abruptly against the softer mica 

 schists. At this point the direction of hade is not very clearly 

 indicated, but on tracing the fault northwards across the hill 

 to the ravine adjoining the mines, the downthrow is clearly 

 seen to be to the south-east. The quartzites thus belong to 

 a horizon lower than that of the schists, and are probably of 

 the same age as the Glen Lyon and Schiehallion grits. In the 

 neighbourhood of the fault the quartzites have been shattered. 



