International audienceThe inventory of more than 200 landslides in the volcanised tertiary basin of Puy-en-Velay (France) reveals a clear bimodality of theirdistribution. The surface magnitude/frequency curve of all the landslides determines 2 power-law adjustments i) the first one with a b = -1.54,corresponding to the ancient landslides and palaeolandslides and ii) the second one with a b = -0.51 corresponding to the historical andpresent-day landslides. The C14 dating of 4 landslides of the first group allows us to determine that Subboreal period was significant foractivation or reactivation of high mass movements. Thus, we conclude that these 2 populations of landslide are the expression of differentclimatic patterns characterised by different level of geomorphic activity. This geomorphic activity is expressed by the synthetic term b of thestatistical adjustments. Finally, the landslides, in the study area, seem to be a geoindicator of this climatic temporal diversity
