Climate reconstructions may be derived from the interpretation of sedimentary proxies. Clay minerals are the only sedimentary proxy used to derive hydrological conditions, beside pollen. Sedimentary clay minerals are a powerful climate proxy if clay minerals are detrital in origin and not altered by burial diagenesis. In sediments, clay mineral variability reflects variable physical and chemical weathering conditions in the watershed, with a significant link to climatic conditions or changes in the mineral source. When different sources are involved, a combination of mineralogical and geochemical proxies allows us to trace the provenance, but they also indirectly provide information on transport pathways and paleocurrents. The session is open to any contribution about the interpretation of clay mineral variability over the Quaternary in both marine or terrestrial sedimentary records in terms of climate control at different timescales and/or transport paths.