Abstract
LONDON. Geological Society, November 9.—Prof. W. W. Watts, F.R.S., president, in the chair.—L. Richardson: The Rhætic and contiguous deposits of west, mid, and part of east Somerset. This paper contains an account of the Rhætic strata of Somerset. The sections at Blue Anchor and Lilstock are described and correlated with those on the Glamorgan coast. The record by Prof. Boyd Dawkins of Rhætic mollusca in the top portion of the Grey Marls is confirmed, and their recognition as Rhætic is substantiated. The deposit between the top of the fossiliferous Grey Marls or “Sully beds” and the main bone-bed at Blue Anchor measures 22 feet, and teems with Rhætic fossils. The beds above the bone-bed agree well with those occupying the same stratigraphical position in Glamorgan. The now obscured sections, that were to be seen in the railway-cuttings at Langport and Charlton Mackrell, noticed by Mr. H. B. Woodward, are described. Huge boulder-like masses of rock were noted at the top of the Black Shales, and the White Lias proper, with a well-marked coral-bed, totalled 25 feet in thickness. The classic sections of Snake Lane, Dunball (Puriton), Sparkford Hill (Queen Camel), Shepton Mallet, and Milton (Wells), have been reinvestigated, and the thin Rhætic deposits in Vallis Vale, at Upper Vobster, and sections in the Radstock district, and on the Nemp-nett and neighbouring outliers, are described. This investigation has shown that the Microlestes Marls are equivalent to the Sully beds; that the Wedmore Stone occurs well below the bone-bed; that Moore's “flinty bed” at Beer Crowcombe is probably on the horizon of the Pleurophorus bed (No. 13); that the Upper Rhætic is as persistent as usual; that the White Lias proper is of restricted geographical extent; and that on the Bristol Channel littoral are marls, “Watchet beds,” above the White Lias. Around Queen Camel, Moore's “insect and crustacean beds” appear to come in at a horizon which lies between the Watchet beds and the Ostrea Limestone. A classification of the Rhætic series is suggested. The fauna of the Rhætian is Swabian in facies, and the conclusion to be derived from the study of the beds is in agreement with Suess's view, that while the dominant movement was one of subsidence and not local but extended, it was, nevertheless, “oscillatory and slow.”—Rev. G. J. Lane: Jurassic plants from the Marske quarry. The Marske quarry is situated on the northern side of the Upleatham outlier in the Cleveland district of Yorkshire. In the quarry several varieties of rock are exposed, namely, shales, small coal-seams, sandstones, and a ferruginous bed. The beds are of Lower Oolite age, and belong to the Lower Estuarine series. From this quarry Dictyozamites was recorded for the first time in England. The writer has obtained nearly forty species from the quarry, among which are many characteristic Wealden plants.
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Societies and Academies . Nature 85, 159–162 (1910). https://doi.org/10.1038/085159a0
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DOI: https://doi.org/10.1038/085159a0