Joining the French Geological Survey (BRGM) means becoming part of France's leading public institution for Earth Science applications bringing together 1,000 wholeheartedly committed experts across 29 bases in Mainland and Overseas France.

BRGM focuses on enhancing geological knowledge and understanding of surface and sub-surface-related phenomena, with a view to: meeting the challenges of environmental changes through innovative projects with societal implications.

This doctoral research aims to enhance our understanding of Quaternary sedimentation in the glacial valleys of the French Pyrenees since the Last Glacial Maximum.

The objectives are twofold:
1. To quantify glacial overdeepening in relation to morphological thresholds;
2. To characterize the succession and geometry of sedimentary deposits (glacial, lacustrine, deltaic, fluvial) from the upper to the lower parts of the valleys.

A post-glacial infill model of the Garonne Valley will be developed to explain the transition between the different depositional environments.

This model will also be used to estimate the aquifer potential of sedimentary formations (subglacial troughs, deltaic deposits, slope contributions).

The PhD candidate will employ a multidisciplinary approach, combining geomorphological mapping, imagery analysis (satellite, elevation), sedimentology (surface samples and drill cores), geophysics, and radiocarbon (¹⁴C) dating.

Altogether, this research will contribute to evaluating the water storage capacity of aquifers and supporting sustainable management strategies for the Adour-Garonne basin.

Context and contributions of the position

The Quaternary deposits found in glacial overdeepening zones are likely to contain natural groundwater resources.

This type of aquifer, which is strategically important in the Alps where it is widely used for drinking water, also has significant potential in the Pyrenean valleys.

Their proximity to major population centers in mountainous areas gives them a high socio-economic value, especially in a context of increasing pressure on water resources.

Adour-Garonne basin—expected to be one of the metropolitan watersheds most affected by climate change—is the focus of a BRGM research project co-funded by local partners (Adour-Garonne Water Agency, Occitanie Region, and the Departments of Haute-Garonne, Ariège, and Hautes-Pyrénées). The aim of the project is to improve hydrogeological knowledge of the aquifers within the geological formations that make up the sedimentary fill of the Garonne Valley.