Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/389

 and flinty, with its joints lined with carbonate of lime. In no spot along the edge of the coal-field immediately east of Leeds have I seen or found recorded in mining-sections any trace of a grit underlying the magnesian limestone.

North and north-west of Barwick-in-Elmet an east and west fault throws out the Coal-measures and brings up the millstone grit, the upper member of which, the Rough Rock, is a coarse and frequently crumbling grit, usually of a yellow colour, and traceable almost without a break eastwards from Meanwood, north of Leeds, to Kidhall Hall on the edge of the magnesian limestone, and again seen in a denudation of the limestone at Bramham Park, where it was taken to be Permian by Prof. Sedgwick. Following the edge of the limestone still further north, the various subdivisions of the Third Grit, with an east and west strike, are successively passed over. Under outliers of magnesian limestone, just south of the river Wharfe and west of Collingham, these grit-beds appear for the first time of a reddish colour in places, and have interbedded purplish micaceous shales; these coloured beds, however, are altogether inseparable from the uncoloured grits, sandstones, and shales occurring further from the borders of the limestone.

The Third-Grit beds across the valley of the Wharfe form a low anticlinal, and on the north side their strike soon changes from an east and west to a northerly direction as far as Plumpton and Knaresborough. The order of succession in the grit-beds near Spofforth is the following. Immediately underlying the limestone is the red and purple grit of Spofforth, Plumpton, and Knaresborough ; its top is not seen, but its thickness probably exceeds 100 feet. Below this come some 50 feet or less of such shales as generally occur in the millstone -grit series, followed by a sandstone, gritty in some parts, and generally of a reddish colour, though not so markedly coloured as the last-mentioned grit ; this rock, which may average some 75 feet in thickness, passes down into sandy and flaggy shales, in many parts having a tendency to be both gritty and of a purplish tint; they contain also numerous worm- and molluscan tracks, and frequently pass rapidly into beds of hardish stone : a good section of these flaggy beds is seen in the railway-cutting about two miles north-west of Spofforth station ; their thickness may be about 50 feet. Next in descending order is a hard sandstone used for road-material, and crowded in some parts with casts of Brachiopods, among the most common of which are Orthis resupinata and Michelini, Strophomena analoga, Productus, and Spiriferina cristata, determined for me by Mr. Etheridge ; the thickness of this bed is about 30 feet. Sixty feet of shale succeed, in turn underlain by what Prof. Phillips has called the " Follifoot coal-grit," for the most part a hard compact sandstone containing a shale-band and thin coal-seam ; whole thickness about 50 feet. Then follow some 400 feet of dark shales overlying the Kinder or Fourth Grit, which is underlain by the Yoredale series cropping up as an anticlinal at Harrogate.

The first and second of these beds of grit Prof. Phillips has thought to be Permian.