Description du sujet de thèse

Context
After growth, the mountain ranges enter into a post-orogenic phase. It is usually not monotonous, as the mountain and its piedmont relief is sometimes reincised (relief rejuvenation). These reincision phases, which are major in the history of the relief of a mountain range, are poorly known and their origin is debated: it could be due to climatic, tectonic and geodynamic or even geomorphological changes. In the framework of the ANR funded Py-10 project, we study the Pyrenees. This mountain range has the advantage of having been less reworked by Quaternary glaciers than the Alps. Moreover, the post-orogenic history is extensive (at least since the Oligocene), with an important erosion renewal at ~10 Ma. Also, the range is small and therefore easy to study, and furthermore, it has been the site of numerous recent studies that have provided a valuable body of data.
Project aims
In Py-10, WP2 aims at establishing a 2.5-D map of the Pyrenees at 10 Ma (paleogeography/ paleoaltimetry), with quantified denudation rates. The PhD candidate will have to synthesize data from recent works on low-temperature thermochronology (e.g. Sinclair et al., 2005; Gunnell et al., 2009; Bosch et al., 2016; Fillon et al., 2021; Capaldi et al., 2022) on paleogeography (Bosch et al., 2016; Monod et al., 2016; Sartégou et al., 2020; Calvet et al., 2021) and sediment routing (e.g. Ortiz et al., 2020). This work will be complemented by the acquisition of new data on palaeoaltimetry (from stable isotope analyses of mammal fossils), sediment provenance (zircons) and drainage divide migration. The main deliverable will be a model of the Pyrenees ca 10 million years ago (10.6 Ma is the time of a large-scale discontinuity in the Pyrenean foreland basins). It will compile, as spatialized data, the environment, relief, elevation, denudation rates, and tectonics of the range and adjacent physiographic areas.

Contexte de travail

The hired person will be located in GET, Toulouse (France). Toulouse is a dynamic city in south-west France: it is the 4th largest city and the 2nd largest academic city (>100,000 students). It is located close to the Pyrenees and Spain. The GET laboratory is part of the University of Toulouse and, within this university, of the Observatoire Midi-Pyrénées, which brings together more than 1,000 people working in the fields of the universe sciences (from astrophysics to ecology, including climate and earth sciences). The PhD will be prepared in close collaboration with the French Geological Survey (BRGM). Within the Py-10 project, the post-doc will have the opportunity to work with scientists from all over France, especially Paris and Toulouse.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Informations complémentaires

Supervision
Vincent Regard (GET, Toulouse) and Bernard Monod (BRGM, Toulouse), in collaboration with A. Ortiz (BRGM, Orléans) and D. Huyghe (Mines Paris).

Person specification notes
We are looking for a PhD fellow with interest and experience in geology, geomorphology, sedimentology.

Essential criteria: the PhD candidate must have a strong background in geosciences or physical geography; she/he must be both autonomous and curious. She/he must have got a research experience in geomorphology, geology and/or sedimentology. She/he must be efficient in writing reports, communicating in a scientific environment, and collaborating with a multi-cultural team. The PhD candidate must feel comfortable with frequent trips for field work and scientific analyses (e.g., Paris, Orléans).

Desirable criteria: Experience in sample chemical preparation; Knowledge of the source-to-sink processes in mountain ranges and their foreland basins; Experience working with quantitative geoscientific data; English reading/writing