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Theses
Transferts du cadmium et du zinc par phase fluide et vapeur dans les processus hydrothermaux et volcaniques: étude expérimentale, modélisation physico-chimique et applications géologiques
Transferts du cadmium et du zinc par phase fluide et vapeur dans les processus hydrothermaux et volcaniques: étude expérimentale, modélisation physico-chimique et applications géologiques
Abstract : The goal of this work is to quantify the role of the vapor and fluid phases in the behavior of Zn and Cd in hydrothermal/volcanic environments, using a combination of laboratory experiments in model systems (solubility, potentiometry, partitioning) and in situ X-ray absorption spectroscopy (XAS) with physical-chemical modeling and analyses of natural fluids. Our results show the formation of chloride complexes with stoichiometries CdClm(H2O)n2-m and octahedral or tetrahedral geometries depending on T and mCl. The thermodynamic parameters generated for these species show that they are the main aqueous species responsible for the transport of cadmium in hydrothermal and volcanic settings. Our data demonstrate that Cd chloride complexes are far more stable than their Zn analogs. The ensemble of experimental, analytical and thermodynamic data obtained in this work permits to propose a new geochemical tracer of the evolution and composition of hydrothermal fluids based on the Zn/Cd ratio.
https://tel.archives-ouvertes.fr/tel-00457869
Contributor : Williams Exbrayat <>
Submitted on : Thursday, February 18, 2010 - 3:49:40 PM
Last modification on : Thursday, October 15, 2020 - 3:12:12 AM
Contributor : Williams Exbrayat <>
Submitted on : Thursday, February 18, 2010 - 3:49:40 PM
Last modification on : Thursday, October 15, 2020 - 3:12:12 AM