Laboratory of Geodynamic and Sedimentary record (LGS)

The cycles of evolution of our planet, its ever-changing morphology and its oceanographic and climate fluctuations are inextricably linked to deep Earth processes whatever the time-scale. Hence, the evolution of continental and oceanic space generates regional changes which are strongly associated with resulting atmospheric and oceanic dynamics and climate variations, passed or future. Apprehending our Planet and modelling its past and future evolution involves understanding the link between the deep and the surface, between the geosphere, biosphere, hydrosphere and the atmosphere and implies an inter and transdisciplinary global approach.

Within this complex system, the role of sediments is unique in more ways than one: produced by erosion, they are the result of a combination of climate and landform variations. Generally transported via the river network to deep ocean basins, they help to interpret the recording of tectonic movement and continental environmental variations, the formation of margins and oceans and their associated movements and last but not least the sea level. So, from the top of mountains to deep-sea trenches, sediment is a time-keeper but also a geodynamic story teller: even its absence is rich in information.  It preserves all signs of its origin and the chemical exchanges of life passed and present. The SEL broaches this geological entity as a memory of the Earth.

The scientific project of the laboratory will address four main interconnected and interdependent themes:

  • Sedimentary recording and the S2S overview,
  • Hydrodynamic processes and the links between the geosphere, biosphere, hydrosphere and atmosphere...
  • The Earth-Ocean system, the Mud2Mantle relation and the specificity of the shelf zone,
  • Global geodynamics, its cyclicity and the link with the geosphere, biosphere, hydrosphere and atmosphere

These four main interdependent themes will be addressed through the three interconnected axes of research:

Axe 1 ‐ Continuum Continent‐Ocean

  • movement and tectonic heritage, Earth-Ocean connection, 3D geometry, nature and evolution of surrounding rock, erosion/deposit record, the specificity of the coastline and anthropogenic impact

Axe 1 concerns geological, geodynamic and sedimentary observations and their results in an earth-ocean continuum and their analyses.

Axe 2 ‐ Paleoenvironment ‐ Paleoclimate

  • Paleogeography, paleo‐relief, paleocurrents and paleoclimatology, the dynamics of atmospheric fronts and monsoons, glaciations and ocean-cyrosphere interaction and the global seawater level

Axe 2 is interested in the links between the geosphere, hydrosphere and atmosphere in time and space and at different scales and studies the environmental variations in relation to these different forcing events.

 

Axe 3 – Modelling

  • stratigraphic modelling on the scale of the basin, process modelling, paleo-oceanographic modelling, lithospheric modelling, paleogeographic modelling

Axe 3, enriched by the two previous axes, attempts to reproduce, with the help of calculators, the natural phenomena observed and test formulated hypotheses.