Claims for Early Pleistocene occupation of the Franch Massif central are examined within the context of the geological setting of the sites. The Massif central is an area where volcanic processes repeatedly fractured stones, thus producing froms that look like humanly modified objects: tephrofacts. The analysis of raw material diversity proves to be an important tool to discriminate between occurences of such tephrofacts and archaeological sites, the earlist of which date from the Middle Pleistocene.