Abstract
Holocene slope deposits at Vaise (Lyon, France) have been investigated (sedimentology, malacology, anthracology, 14 C chronology) along ca. 1 km wide trenches. Three main detrital accumulations have been identified together with more stable areas characterised by a polygenetic paleosol. A mollic horizon with signs of organic clay illuviation ( cf. Argiudoll - Argiboroll) first developed during the Preboreal. A yellow brown argillic horizon (cf . Udalf) then formed as a consequence of the extension of the Atlantic oak forest. The upper mollic horizon is thought to reflect forest clearance and prairie development within the Subboreal, as a response to an important human occupation at the Bronze Age. The soil was finally buried under a thick colluvium from the 1st century A.D.. Mass- and streamflows intermittently occurred along the Holocene. However, the thickest accumulations are related to agricultural landuse during the last two millennia, which induced soil erosion with an intensity never reached since the last glaciation. Slope dynamics seem to be mainly controlled by human pressure, whereas the vegetation documented by anthracology more clearly reflects climate changes. The classical climatic crises of the Subboreal and Sub- atlantic beginnings were not registered here since the forest equilibrium was not affected during these periods.