IN GLEN TILT. 325 



Gotitairiing red felspar, but this extends only a few inches, and 

 graduates rapidly into mica-slate. 



54. Farther to the eastward, within about twenty yards of 

 the end of this reach of the river, and at 8 in the plan, a cut 

 lately made in carrying the road along the top of the bank, dis- 

 plays a junction of the sienite with some strata of hornblende- 

 slate. The strata lie to the eastward of the sienite, and are vi- 

 sible for about seventeen yards. The cut into the rock is of 

 small depth, and, where the substances are in contact, there is. 

 not much to be learnt. But the strata stretch about N. 130" 

 E., and dip to the nor h-east at an angle of about 60°, thus in- 

 dicating a position very different from that of most of the strata 

 already described. In these strata there are some veins of sie- 

 nite. 



55. Beyond this, we observed nothing remarkable on either 

 bank of the river for a considerable distance. 



56. The spot marked B lies about eight hundred yards, in a 

 straight line, above A. Here we found considerable masses of 

 rock, consisting of gneiss, granular quartz, hornblende-slate, 

 granular limestone, and some of the compound substances al- 

 ready described, in strata variously interposed. Some of the 

 limestone is a fine white marble. Rocks of the red sienite al- 

 so appear in many parts of the bed of the rivei', and the face 

 of the southern bank affords a clear view of a body of strata ly- 

 ins over the sienite. 



57. To shew the irregularity that prevails among the strata 

 at this place, and how much their positions differ from that of 

 the great body of strata along the south side of the valley, I 

 shall mention the stretch and dip of several masses within 



Vol. VII. P. II. T t small 



