PalHydroMil

The PalHydroMil project aims at defining a new paleoclimate proxy, based on the hydrogen isotopic composition of a sedimentary molecular biomarker specific of P. miliaceum (miliacin), which will be used for reconstructing past hydrological variability from sedimentary archives. Once established, this new proxy will be used to quantify the hydrological variability during the Bronze Age in the French Alps. The rationale of this project is to initiate a young team at ISTO that will develop a new technique allowing the measurement of hydrogen isotopic ratios (deuterium/hydrogen, D/H or dD) on individual molecules. The focused character of this project (one plant, one molecule) allows us to fully investigate the different aspects of proxy development. It will comprise (1) a rigorous calibration of miliacin dD by cultivation of P. miliaceum plants in controlled conditions; (2) the verification of miliacin dD persistence during diagenesis by in vivo and in vitro degradation experiments; (3) the validation of the approach by comparison of recent miliacin dD evolution with instrumental records and (4) the application of the new hydrological proxy to a high resolution sedimentary series that covers the Bronze Age.