Rock Eval Pyolysis : a tool for quantification of organic fluxes in present lacustrine environnements

The main objective of most organic geochemical studies performed on lake sediments is to identify the sources of sedimentary organic matter (OM). Indeed, molecular and isotopic studies allow to characterise major compositional trends between two organic poles: the one deriving from the lake production (algal and microbial OM), the other one deriving from the watershed production (contemporaneous aerial biomass and reworked OM from soil or geological formations). In order to furnish valid information on the palaeo-environmental variation and on the intensity of responsible sedimentary events (anthropogenic or climatic), it is necessary to quantify the different organic contributions and to calculate the sedimentary organic fluxes through the time.