Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/306

 with a few spangles of mica and a little felspar. Near this, I found granite, which may perhaps be a vein, as the mass is very narrow, and the hornblende rock occurs on both sides of it; but the turf forms so close a covering, and leaves so very little of the rock exposed, that the relation between the hornblende rock and the granite cannot be determined.

§ 23. The western side of this ridge is principally composed of a rock of a reddish-brown colour, in which the chief ingredients are quartz and felspar, together with mica and a little epidote: in some of the fissures of it there are minute crystals of quartz and of felspar. On this side of the ridge I also found granite, containing subordinate portions of hornblende; in some parts of the same mass, the hornblende becomes the prevailing ingredient, and the mica is wholly wanting; thus passing into sienite. It is of very small extent, and the micaceous rock just mentioned occurs on both sides of it.

§24. On the summit of the North-hill, a very small portion of the rock is laid bare, and it is so much decomposed, that a gentle blow of the hammer makes it break down into very small fragments. I succeeded however in obtaining a fracture that shewed the composition of the stone, which is a mixture of hornblende and reddish felspar in very small grains, similar to that noticed § 17 as occurring on the south-east side of the End-hill, and as prevailing very generally throughout the range.

§ 25. A considerable part of the north-eastern side of this hill, is composed of granite. This I have already stated to be identical with that on the opposite side of the valley in the lower part of the End-hill, § 16. This is the only place in the whole range, where I found the arrangement of the rock-masses exhibiting any signs of stratification; but the indications of it are so very indistinct, that I hardly think the rock can be considered as stratified. If it is so,