Description du sujet de thèse

Title : High temperature fluid-rock interactions and their bearing on CRM endowment in volcanic geothermal systems

The aim of the project is to determine if and how the circulation of high-temperature fluids (100-200 °C) in volcanic rocks may modify the mineralogy and affect the mechanical properties of the volcano-sedimentary units to favour the mobilization and transport of critical metals (Li, Cu, B, Ba, P, Ti, Sr, Ge, Sb, etc…) in operational geothermal systems.
To tackle these questions, the PhD candidate will employ different experimental approached that allow for the characterization of mineralogical changes and fluid composition directly at high P-T conditions (in situ experiments), as well as the effect of fluid percolation on the rocks mechanical properties (flow through experiments).

The project involves two secondments of 3 months at the University of Pisa and INGV-Napoli (Italy) to collect natural samples and conduct deformation experiments. Close collaborations with colleagues from the BRGM is also expected to help in the development of new THMC models for metals and geothermal brines. The PhD candidate will thus work in a highly stimulating environment that will offer him/her opportunities to gain a unique expertise in the experimental and thermodynamic modeling of fluid-rock interactions.

Contexte de travail

The PhD project will be conducted at the Institut des Sciences de la Terre d'Orleans (ISTO) in Orleans, France. ISTO is a research institute hosts to >60 scientists and academic staff from Orleans University, CNRS and BRGM.
Our research is organized within three research groups: Magma & Déformation, Systèmes métallogéniques et Géo-énergies & Environnement and is host to a unique experimental and analytical lab dedicated to the study of fluids and magmas under upper crustal conditions (nanofluidic, IHPV, T-IHPV, batch reactors, piston cylinders, microprobe, LA-ICPMS, in situ Raman and X-ray spectroscopy, etc…).
For this project, the PhD candidate will work within the 'Magma et Déformation' and 'Systèmes Métallogéniques' groups. Amongst other subjects, these groups have developed a strong expertise in the determination of pre-eruptive PT conditions, volatiles solubility in magmas or the formation of magmatic-hydrothermal ore deposits. More information can be found under the following link:

https://www.isto-orleans.fr/

The PhD project is also part of the Marie Sklodowska-Curie MSCA Doctoral Network 'MiningBrines' (Multidisciplinary Integration and Networking for INcreased sustainability and multi-resources valorization of Geothermal Brines) that aim at the conception of new extraction strategies for metals from geothermal brines. This project involves 32 international partners and a total of 19 PhDs. The PhD candidate will thus have opportunities to discuss and meet regularly with other PhD students, researchers, academics and industrial partners, for instance during thematic schools (5 over 3years), local and international meetings.

Contraintes et risques

The PhD candidate will have to complete 2 x 3 months secondments in Italy to collect samples and conduct experiments. Funding for the secondments are provided within the MSCA program.
One to two weeks of synchrotron beamtime (ESRF, Grenoble, France) should also be completed.

Informations complémentaires

Required skills : Master in Earth or Material Sciences. Good knowledge of the mechanical and chemical properties of rocks and geological fluids.
Additional skills : economic geology, petrology, high P-T experiments, tomography, XRD, X-ray spectroscopy (fluorescence, XAS), thermodynamic modeling.

Required documents: CV, motivation letter. If possible, a letter of recommendation from a former supervisor.

Expected dates of interview (on line or in person): March 16-30th 2026.