Abstract
GENEVA Society of Physics and Natural History, December 5. LEON W. COLLET: The Jurassic-Cretaceous limit at the summit of Mont Ruan, 3,067 m. (Morcles stratum). The author shows that the limit between Jurassic and Cretaceous is marked by breccias due to the continental movements which gave rise to the Purbeck. LEON W. COLLET and P. VAUGELAS: The geological profile of the Col de Bossetan (Alpes de Samoens, Hte. Savoie). The authors have mapped in detail the Bossetan region on the Swiss-French boundary and give a new section. LEON W. COLLET and AUGUSTIN LOMBABD: The geological profile of the Vallon de Vaugealle (Alpes de Sixt, Hte. Savoie). The authors give a new profile, based on recent detailed observations. ARNOLD LILLIE: The Tour d'Anzeinde and Laubhorn nappes in the internal Pre-Alps between the Arve and the Giffre. The author records the presence of these two nappes between the Arve and Giffre valleys. Hitherto they have been unknown west of Champery. ARNOLD LILLIE: Slices of crystalline rocks in the internal Pre-Alps between the Arve and Giffre valleys. The author describes crystalline rocks which have been found, for the first time, with Ultrahelvetic nysch in this region. M. GYSIN: An attempt at the classification of the granites of the southern Katanga from a planimetric study of thin sections. The author has measured on Shand's planimetric stage the quantitative mineralogical composition of about sixty thin sections of granites. From the results of these measurements, he has grouped the Katanga granites in eight classes. Then, attributing to each mineral a determined chemical composition, he has calculated the average chemical composition of each of these eight classes of rock. G. TIEECY: The law of variation of O or of p in a poly tropic equilibrium of any class. It is a question of showing the equivalence of two equations of condition. P. ROSSIER: The analytical representation of the spectral sensibility of ortho-chromatic plates. The author compares a certain function of the sensibility with some experimental results and finds the results satisfactory. The maximum sensibility is very sharp, especially if yellow filters are used. R. GALOPIN: The chemical differentiation by the spot method of polished metallic minerals.
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Societies and Academies. Nature 137, 121 (1936). https://doi.org/10.1038/137121a0
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DOI: https://doi.org/10.1038/137121a0