Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/283



Further Observations.

[Read 20th December, 1816.]

For the sake of rendering somewhat more complete the history of this substance, I shall here subjoin an account of a considerable body of it which is to be seen in a very unexpected situation in Sky. Although it will be found mentioned in the present volume, in a supplementary paper on that island, it will not be irrelevant to describe it in somewhat greater detail here.

A series of stratified rocks is found extending from the Kyle ric'h, on the eastern side of this island, to Loch Eishort, on its western side, and occupying a considerable space laterally, or consisting of a frequent repetition of the substances which constitute it. While the nature of these strata, which present alternations of red sandstone with graywacké schist, and with indurated grey and blue granular quartz, would incline us to rank them among the secondary rocks, some doubt is thrown on that conclusion in consequence of the peculiar relation they bear to the older rocks which they follow, the gneiss, and the micaceous and chlorite schists. But I must refer to the paper on Sky itself, for the history of these strata, and limit myself to the description of the particular rock which is the object of this note.

It forms a large mass of strata in an erect position, running parallel with the red sandstone and the graywacké schist, which, in repeated alternations, lie on each side of it. These strata, always