Restitution of paleo-environmental changes in North Africa during the Quaternary from a study combining mineralogy and geochemistry investigations of marine cores from the southern Western Mediterranean Sea.

The hydrology of the Mediterranean Sea has an important sensibility to high and low latitude climatic variations. It receives its main fluviatile sedimentary inputs from the north and eolian input from Sahara Desert. Detrital records obtained in the north of the Western Mediterranean Sea are the results of a complex balance between sedimentary sources controlled by high and low latitude climatic systems. This thesis work focuses on marine sediments from the southern part of the Western Mediterranean Sea in an area where the fluviatile inputs are negligeables. This will allow us to mainly establish eolian inputs deriving from North Africa during the Late Quaternary.

North African climate is especially dependent of the Intertropical Convergence Zone (ITCZ) variations during the Quaternary. It controls the location of rain belts, vegetation covers, wind fields and eolian inputs to the Mediterranean Sea. This study combined mineralogical (clay assemblage by XRD) and geochemical (major and traces elements, ⁸⁷Sr/⁸⁶Sr and εNd) compositions analyzed on marine cores in order to establish high resolution eolian record to constrain ITCZ and African monsoon variations during the late Quaternary and to improve our knowledge on sedimentary provinces filling the western Mediterranean Sea.

Thesis supervisor : Christophe Colin (GEOPS, Université Paris-Saclay, France)

Thesis co-supervisor : Zhifei Lui (State Key Laboratory of Marine Geology, Tongji University, Chine)

Doctoral contract (Université Paris-Saclay, France)

International Doctoral Scholarship (CSC, Chine)