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London Geological Society, April 5.—J. W. Hulke, F.R.S., president, in the chair.—W. J. H. Mylne was elected a Fellow, and M. Alphonse Milne-Edwards, of Paris, a Foreign Correspondent of the Society.—Geological age of the Taconic system, by Prof. J. D. Dana, F.M.G.S. The author takes exception to some remarks made before the Geological Society by Dr. T. Sterry Hunt on November 16 last. Dr. Sterry Hunt has thrown doubt on the results arrived at by the geologists who have studied the relations of the so-called Taconic strata, not in consequence of any observations of his own, but on the general ground that “where newer strata are in unconformable contact with older ones, the effect of lateral move ments of compression, involving the two series, is generally to cause the newer and more yielding strata to dip towards, and even beneath the edge of the older rock—a result due to folds, often with inversion, sometimes passing into faults.” It was pointed out in opposition to these views, that the observations of Emmons, H. D. and W. B. Rogers, Mather, Sir W. Logan, James Hall, E. Hitchcock, C. H. Hitchcock, Hager, and Wing, prove that the Taconic schists and limestones are in conformable succession and of Silurian age. The stratigraphical structure of the Taconic range is, indeed, so simple that all observers who have studied it have described the schists and limestones as conformable; and numerous characteristic Silurian fossils have been found in both. This view had been maintained by Dr. Sterry Hunt himself till 1878, when he first propounded his new interpretation of the strata in question; but the latter was not based on any fresh facts or observations. The author's own observations on the subject, carried on during many years, were detailed and illustrated by a map of the whole of the Taconic range. In conclusion, he pointed out that, even if Dr. Sterry Hunt's general principle were conceded, and he was not by any means himself prepared to make such a concession, it would have no bearing on the point at issue; for the supposed younger strata do not dip against the Taconic schists. In opposition to the view that the geological age of strata can be inferred from their mineral characters, he poinied out what remarkably different rocks have been produced by the metamorphism, in different degrees, of the strata of the Taconic range.—On some Nodular Felsies in the Bala Group of North Wales, by Prof. T. G. Bonney, F.R.S.— On the Cambrian (Sedgw.) and Silurian rocks of Scandinavia, by J. E. Marr, B.A., F.G.S. The author has examined the following areas of Cambrian and Silurian rocks in Scandinavia:— (1) Dalecarlia, (2) Ostrogothia and Westrogothia, (3) Christiania, (4) Scania, (5) Baltic Isles. A sketch of the stratigraphy of each of these regions was given, and the author gave the following conclusions:—

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https://doi.org/10.1038/025618a0

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