Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/285

 the left hand. But that position can only be called general, as in every instance all particular or minute regularity disappears wherever the limestone beds are found in the immediate vicinity of the granite. Nothing very remarkable is to be seen between this place and the entrance of the Criny. Near the point of confluence beds of quartz rock are distinctly seen crossing the river, and dipping under the limestone to which they are parallel.

Although various sections of the hills on each side are given by the streams which fall into the Tilt, few of them are sufficiently deep or explicit when singly taken to afford much information about the structure of the hills. The Criny however presents a section of considerable importance, which, as it illustrates the views that I shall hereafter give of the whole structure of this glen, may as well be described here.

The quartz rock which I have noticed as crossing the river, may be traced through the chasm formed by this torrent, and it is found reposing on limestone, which is immediately succeeded by argillaceous schist. I am uncertain whether there is not a thin bed of schist interposed between the quartz rock and the limestone, and I have represented such a one in the engraved section; but it is not important, and the place is so difficult of access, while the confusion produced by the waterfall is so great, that it is difficult to make the investigation minutely. This alternate arrangement is found immediately reposing on the granite, and the schist being the bed in actual contact with the granite, is penetrated by veins precisely similar to those which have already been described. The limestone is here of a peculiar character, being mixed with quartz, sometimes in distinct concretions, sometimes in laminæ irregularly