Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/413

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various parts of Scotland.

mountains, I did not discover any variation from this general character. I should add, that the felspar is the glassy variety.

The cliffs from Loch Skresort to Scuir-more, exhibit the same general appearances of sandstone skirting the shores, and intersected by trap veins, or with masses of trap rocks superimposed on them. A more particular knowledge of this coast is scarcely attainable either from sea or land. At Scuir-more a small beach affords a point of access, and here some variations occur which are worthy of notice.

The sandstone is in this place elevated at very high angles, varying from forty to sixty degrees and upward, and it appears to dip uniformly toward the west. In composition it differs more materially, being ferruginous from oxide of iron, and in place of clay, containing calcareous earth. It is also traversed by numerous minute veins of calcareous spar, and is intersected by innumerable basaltic veins, of different sizes, and often of great magnitude. By these and the subsequent disintegration of the rocks, it is hollowed into caves, and wrought into arches, producing strange and picturesque scenes of ruinous grandeur. I may remark, that the junction of these different rocks does not appear to be attended with any change in the nature of either. In one of the veins there is a portion containing a compound of an uncommon nature, but somewhat resembling the rock above described, being a mixed mass of crystals of augite, hornblende, and felspar. Loose specimens of black pitch-stone are also found on the beach, arising in all probability from some vein of that substance. But the production for which it is most remarkable is the green chalcedony, or heliotrope as it is generally called.

This substance, which exists in large masses, is also found occupying cavities in the basaltic amygdaloid, in nodules varying from the size of a mustard seed to that of a pea. These are

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