Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/172

 thence by Moneymore towards Lissane; on the Canesee river, a small brook which is crossed in passing between the two last mentioned villages, strata of sandstone conglomerate are found.

Near Cookstown, grey sandstone passing into white occurs on the road to Dungannon, it extends beyond the bridge over the Blackwater river, the outgoings of the strata rise south-west 43° under an angle of 8°. There are other sandstone quarries one mile and a half from Cookstown towards Moneymore; a red variety is here found, it is finely granular, with a calcareous cement, the strata crop out south-west 53°, at an angle which varies from 13° to 25° as they increase in depth.

At Coal island, in the county of Tyrone, sandstone constitutes the superficial stratum, two varieties may there be distinguished, both however agreeing in having a siliceous cement; the one is hard, coherent, and finely granular, of a yellowish grey tinge, with spangles of bright mica abundantly disseminated; the other is characterised by a looser and coarser texture, an inferior specific gravity, and fewer spangles of mica.

[This article is supplied by the Editor from the joint observations of Mr. Buckland and himself, the route pursued by Dr. Berger, not having allowed him to examine this formation in the points which exhibit it to the greatest advantage.]

This formation consists of beds of slate clay alternating with thin seams of argillaceous limestone; the limestone is compact but not crystalline, of a bluish colour passing into smoke grey; the fossils which characterise it are cornua ammonia, gryph's, and the columnar