Postdoctoral Position available at Observatoire Midi-Pyrénées (OMP), Toulouse, France Géosciences Environnement Toulouse (GET) and Institut de Recherche en Astrophysique et Planétologie (IRAP) We invite applications for a two-year postdoctoral position at the Observatoire Midi-Pyrénées to study metal-silicate differentiation processes and related isotope effects (see details below). The successful applicant will work at the interface of experimental petrology and isotope geochemistry. He/she will be based part time at IRAP and part time at GET, both laboratories being located in the same building. OMP is a large structure (more than 350 faculty members and 200 PhD’s and postdoctorates) that offers a very stimulating scientific environment due to the diversity and complementarity of research areas tackled there. Applicants should have a PhD in Earth Sciences (experimental petrology, geochemistry, mineralogy). The suitable candidate will show a real motivation for experimental and analytical work, including clean lab work. A good experience in piston cylinder and vertical furnace (1 bar) experiments is highly desirable. A background in isotope geochemistry, if possible applied to planetology and meteoritics is also wished but not mandatory. Interested candidates should send via e-mail their c.v., a letter explaining their motivation for the position and indicating the preferred starting date, and the names and email addresses of three referees to: Dr. Ghylaine Quitté Institut de Recherche en Astrophysique et Planétologie (IRAP) Observatoire Midi-Pyrénées 14 avenue Edouard Belin 31400 Toulouse, France Tel : +33 (0)5 61 33 29 20 [email protected] Deadline for applications: December 15th, 2014 Starting date for the position: Spring 2015 ________ For additional information, please contact: Dr. Ghylaine Quitté (project coordinator) or Dr. Franck Poitrasson for questions related to isotope geochemistry [email protected], [email protected] or Dr. Michael Toplis for questions related to experimental petrology [email protected] Postdoctoral project – Observatoire Midi-Pyrénées, Toulouse (France) Experimental isotope fractionation during metal-silicate differentiation processes in small bodies This postdoctoral position is open in the framework of the PALLAS project, funded by the ANR (Agence Nationale de la Recherche). The project is based on a multi-disciplinary approach that will unravel the initial stages of metal segregation in the solar system through combination of state of the art geochronology, stable isotope cosmochemistry, numerical models of planetary formation and dynamical constraints, experimental petrology, mineralogy, and ab-initio calculations. In this context, a postdoc position is open to investigate compositional and isotopic consequences of metal segregation using experimental petrology. A range of Fe, Cr, Si and Mo stable isotope variations exists among meteorites and may be explained by isotope fractionation during planetary accretion or differentiation processes. To determine the exact conditions that prevailed during metal segregation, piston cylinder and multi-anvil experiments have already been performed. If the understanding of Fe isotope fractionation under metal-silicate differentiation conditions has made considerable progress, results obtained on Si isotopes are still a matter of debate and no systematic experimental work has been done thus far for other key elements such as Ni, Cr, and W. The aim of the present piece of work is thus to quantify the isotope fractionation of Si, Ni, Cr and W associated with kinetic and equilibrium processes during metal-silicate differentiation. We will then compare these data measured in laboratory experimental products with results obtained by other colleagues involved in the project, both on natural samples (meteorites) and using ab-initio calculations. Two different sets of experiments are planned: • low pressure (1 bar) metal-silicate equilibration in a CO/CO2 vertical gas mixing furnace • high pressure (1-3 GPa) metal-silicate equilibration in a piston cylinder After each experimental run, a careful sample characterization (SEM, EPMA, FIB/TEM) will precede determination of the concentration profiles of the different phases as well as the associated isotope composition (Si, Ni, Cr, W) by multi-collection inductively coupled plasma mass spectrometry (MCICPMS). Bulk analyses of the silicate and metallic products measured in solution will be coupled with in-situ analyses using laser ablation (femtosecond LA-ICP-MS).