Weathering of silicate rocks acts as a major sink for atmospheric CO2, and hence is thought to have played an important role in regulating the Earth’s climate over geological time. Despite the potential importance of this process, and its significance to the global carbon cycle, our ability to reconstruct past variations in silicate weathering remains limited. Another important issue is the degree to which human-induced environmental degradation has affected continental weathering on shorter time scales, from tens to thousands of years. A better understanding of how chemical weathering relates to climate change and human activities is necessary to address these issues.The SI-PALEO project proposes to explore the use of silicon isotopes in marine sediments as a new proxy for past continental weathering. Recent advances in the understanding of the biogeochemical cycling of silicon on continents have shown that Si isotopes could provide a unique tool for tracing the evolution of silicate weathering through time. In this study, the main objectives will be: 1) to determine the factors controlling the distribution of Si isotope ratios in terrigenous sediments, and 2) to assess the impact of climate change and human activities on past chemical weathering in Central Africa. These objectives will be addressed by analysing an extensive collection of river-borne sediments and exceptional marine sediment records from the Congo area.SI-PALEO is a multi-disciplinary project, proposed together by a French marine geoscientist and the Royal Museum of Central Africa (Belgium), a first-class centre for scientific research in Africa with expertise on Si isotope geochemistry, Earth Surface processes and archaeology. The data acquired during this project should improve our understanding of past interactions between climate, environment, and human activities. SI-PALEO will also contribute at strenghtening the applicant’s position in this novel frontier area of research.