IN GLEN TILT. 327 



the limestone on its sides. The outlines of these veins are 

 often extremely irregular, and their breadth is rapidly va- 

 ried. 



60. The strata on the northern bank, described above as 

 consisting of actinolite, felspar, mica, and carbonate of lime, 

 are cut by small veins, partly of red felspar, and partly of the 

 red sienite. The outlines of these veins are very regular and 

 distinct. 



61. To the eastward of these strata is a greenstone porphy- 

 ry, similar to that of the dyke below Gow's Bridge. I con- 

 ceive it to lie here in a bed conformable to the strata. 



62. In many of the veins at B, shifts, or slips, are very con- 

 spicuous, and they occur even in veins of large dimensions. 



63. Within a hundred yards above B, the strata appear in 

 the bed of the river in several places, and are much intersect- 

 ed by veins of sienite, or sometimes perhaps felspar. 



64. The spot pointed out by the letter C lies about 260 

 yards above Forest Lodge. There is here a fall in the river> 

 and large masses of rock appear on both sides of it, but they 

 do not afford much information to the geologist. 



65. Those on the southern bank are strata, which seem to 

 consist either of granular quartz, or of compound quartzose 

 substances, similar to those at A. There is a mass of granu- 

 lar quartz standing up in the middle of the stream. 



66. On the northern bank, the rocks are an aggregate of red 

 and grey felspar, intermixed with black or greenish hornblende. 

 The hornblende is in a large proportion, and the stone may be 

 considered as one of those gradations between sienite and sie* 

 nitic greenstone, which have been already described. The 



T t 2 rocks 



