GET > Research > The 9 Major Themes > T8 : Stable Isotope Geochemistry (GIS)

Research

T8 : Stable Isotope Geochemistry (GIS)

Group Leader : Jeroen Sonke (DR CNRS)*

Participants :

François-Xavier D'ABZAC, Marc BLANCHARD, Jérôme CHMELEFF,  Laure LAFFONT,  Merlin MEHEUT, David POINT,  Franck POITRASSON, Jeroen SONKE

Contractual researchers & Post-docs:

Jeremy GUIGNARD, Martin JISKRA, Jean-Sébastien MOQUET

PhD students:

Ségolène RABIN - Mécanismes de distribution des isotopes du fer et du silicium entre les minéraux et les liquides silicatés lors de la différenciation des magmas (Dir. F Poitrasson) Since 10/2017

Xu YANG - Atmospheric mercury isotope biogeochemistry (Dir. J. Sonke) Since: 10/2015

Chuxian LI - Mercury stable isotopes in southern hemisphere peat archives (Dir. F. de Vleeschouwer/J. Sonke) Since: 10/2015

clusterFe-2

Electronic structure of Fe2+ (left) et Fe3+ (right) in aqueous phase. Figure published in Elements 6: 369-374, posted with permission of the publisher

In the last decade, multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) has allowed to explore a new research field in the geosciences: the fractionation of "non-traditional" stable isotopes, like those of iron, silicon, mercury, zinc or magnesium. The investigation conducted by the international community have illustrated the interest of the "non-traditional" stable isotopes since they frequently show different fractionation processes compared to "traditional stable isotopes" (of carbon, oxygen...) because they are located in specific crystalline sites, they form different aqueous species or are affected by specific processes (like a change of the redox state of iron or the radical chemistry of mercury). The GIS group also develops compound specific isotope analysis of organometallic contaminants such as methylmercury, i.e. determining the carbon and mercury isotope fingerprints of the same molecule

Globe2

crédits: C. Cavare-Hester

 The studies conducted at GET, published since 2004, allowed to show that "non-traditional" stable isotopes give the opportunity to study from a fresh perspective big scientific questions. We notably study iron isotope fractionation occurring during the formation and differentiation of terrestrial planets, the adsorption of Zn and Cu isotopes microorganism cell membranes, the behaviour of Zn and Hg isotopes in the pollutant cycles in the environment. We present here some of the research directions developed under the current five year plan (2016-2020).

 
Vinto fumee

Photo:  J. Gardon

*DR CNRS: Directeur de Recherches CNRS
Phys. Adj. OMP: Physicien Adjoint, Observatoire Midi-Pyrénées
IR CNRS: Ingénieur de Recherches CNRS
AI CNRS: Assistant Ingénieur CNRS
DR IRD: Directeur de Recherches, Institut de Recherches pour le Développement
MCF UPS: Maître de Conférences, Université Paul Sabatier

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