paleoclimat – A site of the University Paris-Sud

MAIN THEMES

of the team

The research activities carried out by the Paleoclimates and Sedimentary Dynamics (Paléoclimats et Dynamique Sédimentaire; PDS) team in the GEOPS Laboratory (UMR-CNRS 8148) focus on reconstructing Quaternary climatic changes at various time scales (ten-year to orbital scales) by studying existing interactions within the external compartments of the Earth’s system (oceans, atmosphere, continental surfaces).

The aim of this research is to gain a better understanding of:

• The modalities of the formation (erosion/alteration), transfer (Aeolian and fluvial transportation) and deposition (dispersion) of sediments found in the oceans, in relation to changes in the hydrological cycles of low and middle latitudes, and particularly in the context of the Monsoon.
• The impact of changes in ocean circulation and biological productivity of the high southern latitudes on the carbon cycle, and particularly on changes in atmospheric pCO₂.
• The dynamics of ocean circulation (thermohaline) through the study of local to regional hydrological conditions, in order to tackle the question of inter-hemispheric connections.

These three main themes together depend on the calibration of paleo-oceanographic tracers. They are essentially based on the study of marine and lacustrine sedimentary archives, which present temporal frameworks that are constrained by stratigraphical and radiometric methods and/or by tephrochronology.

The research activities of the team are based on the use of various tools (the PANOPLY platform) within the fields of sedimentology (granulometry), mineralogy (clays), paleontology (coccolithophores, foraminifera, deep sea corals), and elemental- (Mg/Ca, Sr/Ca, Br/Ca, etc.) and isotopic- (δ¹⁸O, δ¹³C, εNd, ⁸⁷Sr/⁸⁶Sr) geochemistry.