Postdoctoral research position

25 September 2022 par Anne Delplanque
The aim of this postdoctoral project is to develop and test new parametrizations describing the feedbacks between fluids/melts and deformation, focusing on the effect of fluids/melts on the rheology of rocks in the ductile field.

Starting date: Ideally January 1st, 2023
We are looking for highly motivated candidates with strong numerical and methodological skills. At the time of appointment, the candidate must hold a PhD degree in geophysics, geology, mechanics, physics, applied mathematics, or a closely related field. A proven expertise in numerical modelling and programming, as well as excellent English skills are required. Knowledge in petrology and rock deformation and/or previous experience in the simulation of flows in solid-liquid systems will be highly valued.

EBSD phase map of a peridotite mylonite (red:ol, blue:opx, cyan:amph).

Natural systems show clear evidence of such feedbacks. However, the large observational dataset collected by our team indicates that some important feedbacks cannot be reproduced in laboratory experiments due to their slow kinetics. Hence, numerical models are required. The postdoctoral fellow will use numerical models of two-phase systems (solid+liquid) where the solid phase deforms by ductile (viscoplastic) processes to analyze and quantify the feedbacks between fluid/melt percolation and strain localization at the sample to km scale focusing on slow kinetics processes like fluid-mediated dissolution-crystallization. The results of these simulations will allow to refine the existing, fully empirical flow laws for ductile deformation in presence of fluids/melts. The outcomes of this project will also have applications for the simulation of fluids and melt transport in the mantle and lower crust.

In practice, the postdoctoral fellow will:
- synthesize, in collaboration with the other researchers of the ERC RhEoVOLUTION team, the geological observations constraining the feedbacks between fluids/magmas and deformation in natural systems, both in the mantle and in the ductile crust (a large database on the topic has already been assembled by the team and new studies are in progress in the frame of RhEoVOLUTION);
- define the numerical experiments best suited to quantify these feedbacks in two-phase flow systems;
- adapt existing or develop new codes to carry out these experiments;
- carry out experiments, analyze them and, based on these results, derive parametrizations for the effects of these processes in geodynamic simulations without explicitly simulating the flow of fluids/magmas;
- implement these parameterizations in geodynamical simulations and use them to characterize the role of fluids/melts on strain localization.

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