Vol. 65.] 



THE CAULDRON-SUBSIDENCE OF GLEN COE. 



G55 



reddening of the schists. Like the latter phenomenon, they are not 

 found within the circumference of the inner fault, nor do they 

 extend far beyond that of the outer one. They are probably older 

 than even the early fault-intrusion : for they do not cut the latter, 

 although it crosses the zone of their maximum development. 



Proceeding west-north- westwards from Sron a' Choire Odhar-bhig, 

 we may follow the line of the older fault to the point where it is 

 finally lost sight of. It presents no special point of interest, until 

 the slope is reached looking down into Coire Mhorair. The flinty 

 crush, affecting both schist and early fault-intrusion, is well exposed 

 here, and the fault-plane overhangs, having a northerly inclination 

 of 70° measured from the horizontal (F 1 of fig. 10). The old line 

 of movement has been followed, as is so often the case, by later 

 shattering. Half way down the hill-slope a. sudden change occurs 

 in the direction of the porphyrite margin, and presumably also of 

 the fault itself. The former is seen to turn sharply through a right 

 angle ; and, instead of being inclined at 70° north-north-eastwards, 

 it now dips north-north-westwards at about the same angle. The 

 bend must be very abrupt, but it is obscured somewhat by later 

 crn shing. 



Fig. 10. — Section through the ridge west of Coire Odhar-mhor. 

 S.W. N.E. 



\F X & F„ = Early faults, accompanied by fault-intrusions; F 3 =Main fault 

 with fault-intrusion.] 



Returning to Sron a' Choire Odhar-bhig, it is an easy matter to 

 trace the inner branch of the fault westwards into Coire Odhar- 

 mhor. Here it makes two short but sudden bends recalling the 

 one just described in the older fault : the sections, however, are not 

 quite so clear. 



Ascending the slope on the western side of Coire Odhar-mhor, 

 the;[fault obviously overhangs (F 3 in fig. 10), and is accompanied 



Q. J. G. S. No. 260. 2 x 



