EXCURSION XIV. 177 



sandstone is indurated along the lines of contact, and the 

 strata shifted out of parallelism. The effects of so small a 

 stream are quite wonderful to contemplate here, and suggest 

 the idea that it must have been of larger volume in bygone 

 times. Ballymenooh stream, a little way east, shews some- 

 what similar appearances; and farther west, near Benan- 

 head, on the north side of the road, there is a fine section of 

 the same kind. The stream has cut down the strata to a 

 depth of seventy feet, in a fine cascade; and a trap dike, 

 after traversing the sandstone strata, loses itself in the over- 

 lying greenstone another clear case of a lava-chimney. 

 Calcareous nodules, rarely exceeding six inches in diameter, 

 are disseminated through the sandstone, both here and in 

 several other sections; and Mr. Headrick mentions (p. 117) 

 that a small cascade on a rocky front south of Auchinhew 

 burn, has deposited a mound or small hill of stalagmites, or 

 lime incrustations, shewing that lime prevails in all the 

 sandstones here, and hence that these probably are the true 

 carboniferous beds. The high grounds north of Benan-head, 

 which reach 523 feet in altitude, consist of felspar porphyry, 

 and greenstone, the former generally in a superior position, 

 but in some places coming against the latter at the same 

 level. 



83. The Struey rocks and Benan-head form, both for the 

 geologist and botanist, one of the most interesting features of 

 this coast. The headland is 457 feet high, and is a mass, 

 from top to bottom, of igneous products, variously inter- 

 mingled, but consisting chiefly of a dark-based felspar por- 

 phyry, basalt and greenstone. The crystals imbedded in the 

 dark compact felspar base are of that variety of felspar called 

 pearlstone, with which are commingled quartz crystals of a 

 smoky hue. In the greenstone there are dark-coloured 

 crystals of hypersthene with the lustre of crystals of oxide of 

 iron. It is difficult to make out exactly what are the 

 relations of these rocks to one another in the headland. In 

 some places they are intermixed, and perhaps alternate in 



