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Doc. Labo. Géol. Fac. Sci. Lyon, n° 21

 

Notes et mémoires (1967) - Travaux
de DAVOINE, DAVID, MARTIN.
100 p., 23 texte-fig., 7 tabl.


Sommaire

P. DAVOINE - L'analyse chimique des roches silicatées. abstract

L. DAVID - Baudran, nouveau gisement de Vertébrés quaternaires sur le Causse de Martel. abstract

R. MARTIN - Le Glouton de Villereversure. abstract

 

Abstracts

P. DAVOINE - L'analyse chimique des roches silicatées

This text is applied to students of geology bringed to take interest in the chemical analysis of silicate rocks. The determination of the 11 main elements are based upon the decomposition of 3 separate samples which will be designated I, II, III.

Sample I is decomposed by cold mixture (15° C) of hydrofluoric and sulfuric acids. In the resulting solution, iron ferrous is determined potentiometricolly.

Sample II is attacked by fusing with Na2CO3 and K2CO3 (1000° C) and dissolved in dilute HCl. The silica titration is determined gravimetrically. Five aliquot portions are taken for iron ferric, aluminium, calcium and magnesium complexometric titrations (EDTA) and the phosphorus absorption spectrophotometric titration.

Sample III is decomposed by hot mixture (90° C) of hydrofluoric and sulfuric acids and dissolved in dilute H2SO4. In the resulting solution, sodium and potassium emission spectrophotometric titrations (flame) and manganese and titanium absorption spectrophotometric titrations, are established.

This analytical method is used in a routine manner by some rocks analysis laboratory. It is used also in earth sciences department in Lyon.

 

L. DAVID - Baudran, nouveau gisement de Vertébrés quaternaires sur le Causse de Martel

A new fossiliferous area in SW-France. Only remains of three species of mammals were discovered in the upper part of alluvions in a chasm. The present study however gives a relative description of deposits in this pleistocene cave.

 

R. MARTIN - Le Glouton de Villereversure

At Villereversure near Bourg-en-Bresse (Ain) a deposit of fossils mammals has been searched by J.M, BEROUD (1883) and a first study has been published by E. CHANTRE (1901) ; the Author who has assumed the revision ot the fauna sets forth in this paper the remains of eight Gulo gulo : he gives a detailed description of the teeth and the long bones. He concludes by a few hypothesis concerning the date of the deposit : the lower layers, containing Reindeer, may be regarded as Riss in date, whereas the upper osseous deposit which is in four different and successive layers is to have been setting up during the most important part of Würm.