PARTIAL-DERIVATIVE-C-13 CHANGE BASED ON M EDITERRANEAN PREHISTORIC AND HISTORIC CHARCOAL FROM 35,000-BP TO PRESENT - FIRST RESULTS

partial derivative(13)C isotopic analyses based on preliminary samplin g of prehistoric and historic charcoal from-the South of France, betwe en 35,000 BP to present, give us two types of result. The first, based on isotopic Pinus sylvestris analyses, give evidence of great wet-dry variations during the late glacial representing precipitation 60% low er than at present. The other results, based on a preliminary analysis of a Holocene deciduous oak series lower than at present are consiste nt with smaller wet-dry variation than during the Pleistocene. The mos t significant variations are placed during two important periods of th e postglacial history, early Atlantic/late Atlantic (ca 6,000 BP) and during the early Subboreal. These two periods of variation are consist ent with increasing humidity leading to landscape erosion accentuated by human action.