Gaelle Lamarque

Passive margins geodynamics: insights from seismic anisotropy

PostDoctoral Fellow: Dr Gaelle Lamarque
Scientific Sponsors: Dr Mikael EVAIN (Géosciences marine - Ifremer)
LabexMER Research Axis: Axis 4: Sediment transfer : source to sink, and mud to mantle

Passive margins experience numerous stages of subsidence and uplift throughout their evolution. From the initial rifting phase (pre-rift) to the break-up of a continent (syn-rift) and later possible post-rift surections, all these events are recorded by the presence or absence of both land and marine sedimentary deposits. However, understanding the tectonic processes and the dynamics at depth controlling successive vertical movements of passive margins remains one of the major challenge facing the geoscience community. This project aims at having a fresh look at passive margins geodynamics by means of seismological data. In particular, we plane to use and develop new methodologies from receiver functions and surface waves to finely map anisotropic structures within the lithosphere (crust and mantle). The seismic anisotropy reflects the deformations which occur after tectonic activity either in brittle (faults) or in ductile (lattice prefered orientation of minerals) domains. It is thus a powerful tool to understand lithospheric inherited and current structures as well as past and present deformations.