Mineral magnetic susceptibility and palynological evidences of human impact and fluvial process in the lower Doubs valley (Jura, France) between 1(st)-8(th) century AD.

Surface scanning magnetic susceptibility, microscopic charcoal counting and pollen analysis have been carried out on two cores from the lower Doubs va lley. The interpretation of anthropogenic pollen indicators is discussed in relation to the lithological variations of sedimentary accumulation. The e nvironmental changes which occurred during the 1(st) and the 6(th) century AD reflect the impact of human activities on the landscape in the immediate surroundings of the site. Magnetic susceptibility and pollen analysis indi cate soil erosion as a consequence of agricultural activity. A renewal of h ydric activity of the river recorded in the sedimentary sequences attests o f a larger environmental evolution during the 3(rd) century AD. (C) 2000 Ac ademie des sciences/Editions scientifiques et medicales Elsevier SAS.