ARRAN. GEOLOGY. OVERLYING ROCKS. 407 



sandstone beds is found, and these abut against it; the 

 ends of the strata in contact with the felspar rock, 

 being slightly turned up out of their general direction. 

 In following these strata eastward, the felspar rock is 

 again seen passing once more in a vertical direction 

 through the mass of strata, and with the remarkable 

 appearance represented in the subjoined sketch.* Beyond 

 this there is a third and very distinct vein visible, present- 

 ing a similar connexion and a prismatic fracture. It is in 

 this place that the crystalline change of the sandstone 

 formerly described, occurs. 



It is unnecessary to describe any more of those veins 

 that traverse the sandstone strata, as none of them appear 

 to be attended by peculiarities worthy of notice. But 

 it is a necessary part of their geological history to men- 

 tion that they occasionally traverse the granite ; in which 

 respect also they present a common feature with the 

 ordinary trap rocks. They are however far less common 

 than trap veins in those situations, as I only discovered 

 one example in situ, although indications of them are to be 

 found in other places. The vein to which I allude is 

 found near the summit of Goatfell, and consists of a grey 

 compact felspar interspersed with white crystals of the 

 same mineral. It is very intimately united to the granite 

 at its edges. The indications above mentioned, consist in 

 scattered masses of indurated claystone and of felspar 

 porphyries, which are found on the sides of Ben vearan in 

 different places, and are doubtless derived from veins, 

 although I was unable to detect them. It is superfluous 

 to enumerate any more of these local details, as they are 

 uninteresting in a topographic view, and as the places 

 already described afford sufficient foundation for examin- 

 ing the geological relations of the several rocks to each 

 other and to the strata which they accompany. With 

 respect to the former, all the varieties are found to be con- 



* Pi-ate XXIV. fig. 3. 



