AND OBSERVATIONS. 



107 



ward through the alpine district, as Glencroe ; in 

 which primitive greenstone seems to be abundant, 

 throughout the mica-slate. 



Dalmaly. — At Dalmaly, limestone occurs near 

 the inn : likewise greenstone, compact chlorite, and 

 a substance consisting of hornblende and chlorite 

 mixed. The limestone and greenstone form hills, 

 containing veins and beds of quartz. But the pre- 

 vailing rock, in situ, is newer mica-slate, and clay- 

 slate, or clay-slate passing into talc-slate ; including 

 beds of chlorite, sometimes intermixed with felspar, 

 and with iron pyrites. The same substances, along 

 with greenstone and hornblende rock, are found in 

 the mica-slate, of which Ben Loy, a lofty moun- 

 tain to the eastward of Dalmaly, is chiefly com- 

 posed ; and which exhibits great variety of struc- 

 ture, from its different proportions of quartz. Some 

 specimens of it contain iron pyrites, and small 

 portions of hornblende. The strata incline to the 

 north-west, at an angle of about 40°. 



Cruachan. — Of Cruachan itself, the fundamen- 

 tal rock, I presume, is granite ; which appears also 

 at the summit ; but, in the lower parts of the moun- 

 tain, on the south and east, is covered by a variety 

 of other substances or formations, among which are 

 syenite, and hornblende rock. Along the base, at 

 the head of the river Awe, we have beds or strata 

 of clay-slate, alternating with chlorite, hornblende, 

 and greenish-coloured felspar-porphyry, with crystals 

 of felspar. The clay-slate is found westward, as far 



