Postdoctoral research position in geodynamics: Thermal evolution of the lithosphere of the Aquitaine Basin (M/F)

Job Description

Missions

The objective of this post-doctoral research is to quantify the evolution of the thermal
structure of the Aquitaine Basin's crust and mantle using the geological record.
Geophysical data, the subsidence history of sedimentary basins, and thermal-mechanical
models indicate that the thermal structure of the European lithosphere remained stable during
the Mesozoic, potentially due to small-scale convection at its base. To evaluate this hypothesis,
the study proposes to cross-correlate thermal proxies, including changes in thermal buoyancies
recorded in the elevation history, with existing and newly acquired temperatures inferred from
mafic magma reservoirs hypothesized to exist at the base of the lithosphere beneath the French
Massif Central and the Pyrenees.
Thermometric analyses of mineral assemblages (e.g., olivine-bearing basalts) will be used to
estimate magmatic temperatures at the base of the lithosphere. Crustal cooling histories and
potential thermal rejuvenation events will be reconstructed using existing low-temperature
thermochronology and P–T–t data, contributing to a new lithotectonic map of the Aquitaine
basement. The present-day lithosphere temperature structure will be modeled using petrophysical
modeling (LitMod2D 2.0 software) along a ~1000 km transect (Paris Basin to
Aquitaine Basin), incorporating constraints from topography, heat flow, gravity, geoid, seismic
velocities, and recent mafic volcanic rocks (<10 Ma) as proxies for the mantle's thermal
regime.

Activity

The postdoctoral researcher will conduct a tectonic synthesis of the Aquitaine Basin and its
surrounding regions, with a focus on metamorphic and magmatic units. The role will involve
participating in field sampling campaigns and performing whole-rock and microprobe
analyses on newly collected basalt samples. Additionally, the researcher will update the
Georoc database with bibliographic data published since 2015 and progressively develop a present-day lithospheric model using LitMod2D 2.0.

Your Profil

Skills

The candidate must have a strong background in geodynamics, with solid experience in the petrology of magmatic and/or metamorphic rocks, as well as an experience in the construction of crustal-scale tectonic cross-section and multi-scale studies of the continental lithosphere.

Your Work Environment

The postdoctoral researcher will be supervised by Yoann Denèle, Alexandra Robert, Jerôme Ganne, Sébastien Chevrot and Frédéric Mouthereau (GET-Toulouse). The PostDoc will be based in the GET. The GET is a joint research unit of CNRS, IRD, Toulouse University and CNES, a multi-disciplinary research laboratory in Earth and Environmental Sciences attached to the Observatoire Midi-Pyrénées (https://www.omp.eu/), which brings together laboratories working in the sciences of the universe, the planet and the environment in the Midi-Pyrénées. The successful candidate will benefit from the analytical infrastructure available at GET-CNRS (University of Toulouse). This includes a high-quality microscope platform and thin section production service, a Electron Probe Micro Analyser, a micro-XRF instrument, a SEM equipped with EDS, STEM and EBSD detectors, a laser-ablation–coupled mass spectrometer for U–Pb dating.

Constraints and risks

none

Compensation and benefits

Compensation

from 3041 to 4216€ monthly gross salary depending on the candidate experience

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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