149 



CRAIG-DHIT. The Craig-Dim granite has been fully described 

 already (Art. 51). Craig-Dhu is a high steep cliff fronting that 

 part of the Shiskin road where the road to Dugarry parts off from 

 it. A talus of blocks strews its base. We noticed, from a distance, 

 in driving along the road with a party of friends in July, 1855, how 

 unlike these were to sandstone blocks, and were thus led to the 

 discovery of the granite tract. It struck us as remarkable, that, 

 on a route so frequented, the occurrence of the granite here had 

 so long remained unnoticed. 



CLACHAN GTLEN. The upper beds of the Old Red rise into the 

 lower part of this glen; the middle and higher parts show the 

 lower and middle beds of the carboniferous system, which pass over 

 the watershed towards Lamlash. High on the south side of the 

 glen, apparently by an upthrow of the strata, beds of white lime- 

 stone with quartz pebbles, like that of Aehab farm and the Fallen 

 Rocks, are brought to the surface. The metamorphic action 

 towards the head of the glen is the most extensive and remarkable 

 which we have seen in Arran. All the ordinary characters of the 

 sedimentary strata are obliterated. 



TRAVELLED BLOCKS. Leaving the Shiskin road and taking 

 that to Dugarry in order to reach Mauchrie waterfoot, we are cross- 

 ing in front of the fine-grained granite tract of Glen lorsa; and 

 accordingly we find that here the great proportion of the boulders 

 are of this variety of granite ; while those on the eastern side and 

 along the south plateau, are of the coarse variety. This points 

 to a cause locally acting in the direction of the glens ; we never 

 find lorsa granite on the east side of the island; both kinds are 

 mingled on the west side (see Art. 60). 



THE TOEMORE PITCHSTOITES. We cross from the Dugarry road 

 by the mouth of the Mauchrie to reach Tormore. Less than a mile to 

 the south, in front of the sandstone cliffs of King's Hill, there occurs 

 the finest set of dikes to be seen in Arran, exhibiting, in a small 

 space, all the members of the igneous series, greenstone and basalt, 

 porphyry and trap porphyry, pitchstone, claystone, and hornstone. 

 To understand the relations of the various dikes, the shore should 

 first be traversed several times, the whole extent being only a few 

 hundred yards. The sandstone platform is bounded southward by 

 the sea, and by a mural precipice sixty feet high, along the base of 

 which there is no passage southwards, except at low water. This 

 precipice is the western front of an immense dike of felspar por- 

 phyry, eighty to ninety feet wide, ranging a few degrees N. of E., 

 and here taking the place of the sandstone in the cliff for a con- 



