MARINE BANDS IN THE MILLSTONE GRIT OF WHARFEDALE.

Abstract

( Read 4 th March , 1909. Manuscript received 8 th November , 1909.) About one mile to the north of Otley there is situated, on the sides of Clifton Beck, a large exposure which shows the following succession, dipping at an angle of 12° to the southeast:— | Top not seen. | |:-------------:| --- | | ft. | in. | | | | | 50–60 | | … | … | Hard black shale. | | | 4 | … | … | Black micaceous sandy shale. | | 1 | | … | … | Yellow micaceous sandy shale. | | | | | | Weston Grit. | | | | Base not seen. | | At the base is the Weston Grit, which is seen in the bed of the stream, and this passes up into a soft, very micaceous, yellow shale, containing Glyphioceras bilingue, which is succeeded by a thin band of black micaceous shale, with Posidoniella lœvis. Overlying this bed is the main mass of black carbonaceous shale with very little mica, which is very hard at the base, but towards the top becomes softer and more ferruginous, weathering into boxstones. In the lower part are several small layers of crystalline limestone with crinoid stems, but none of these layers is more than a quarter of an inch in thickness. There are also numerous small nodules, both of iron-pyrites and earthy limestone, without fossils. From the shale itself the following fossils have been obtained:— Echinodermata. Crinoid stems. Lamellibranchiata. Chœnocardiola Footii. Aviculopecten carboniferus. Pterinopecten papyraceus. Pseudamusium fibrillosum. Posidoniella lœvis. Posidoniella Kirkmani. Cephalopoda. Glyphioceras bilingue. Glyphioceras micronotum. Orthoceras (striatulum) ? Orthoceras Morrisianum. Another locality where I have found marine bands is near Fewston. Here a tunnel has lately been …