Description du sujet de thèse

The energy sovereignty of France and Europe requires greater knowledge of local resources, particularly uranium. The Permian-age Lodève Basin contains one of the most significant uranium resources in France, which was mined in the second half of the 20th century, with more than 14,000 tonnes extracted. The URALOD project, a key project within the NEEDS programme, aims to establish a new vision of the formation of the Lodève deposit based on recent concepts in metallogeny and modern techniques for characterising uranium mineralisation and hydrothermal circulation in sedimentary basins. In this context, we are proposing a thesis topic on multiphysical modelling (geometry, geophysics, hydrothermal modelling) of uranium mineralising circulations in the Lodève basin. Our preliminary results encourage us to include in this research project an investigation of the neighbouring basins of St Affrique and Rodez, which are most likely genetically linked to the Lodève basin during the Permian period. This will involve specifying the geometries of these basins and identifying traces of hydrothermal circulation carrying uranium mineralisation, through fieldwork and petrology and mineralogy studies, similar to what we have initiated for Lodève. Establishing a genetic relationship between these three basins will enable us to better define the extent of uranium mineralisation, propose a regional-scale mineralisation model, and ultimately specify its geometric characteristics.

Contexte de travail

The thesis will be carried out within the FRODO team, a constituent team of the Géosciences Rennes laboratory.
Géosciences Rennes is a joint research unit in Earth and Environmental Sciences with the CNRS and the University of Rennes 1 as trustees. This multidisciplinary unit focuses on geological processes and the evolution of continental surfaces at long time scales, as well as the functioning and dynamics of our natural environment (the critical zone) on human time scales. In addition to this diversity of time scales, the work ranges from microscopic to nanoscale to continental. One of the particularities of the unit is also to take a strong interest in societal issues through the establishment of resources (water, energy, minerals), the potential impact of man on environments (e.g., emerging pollutants) and natural hazards. The approaches developed revolve around observation, numerical modelling and laboratory experimentation, relying on a remarkable instrumental and analytical park, highly efficient and in perpetual innovation.
The FRODO team aims at studying and characterizing the interactions between geological fluids, rocks (basement, basin, magmatic) and their deformation, through the coupled use of field geology and numerical modeling of processes.