POLLEN ANALYSIS OF A LONG UPPER PLEISTOCENE CONTINENTAL SEQUENCE IN A VELAY MAAR (MASSIF-CENTRAL, FRANCE)

A new 20 m sequence is presented which is based on 279 spectra derived from a coring at Le Bouchet lake (Massif Central, France). The vegetational history of this region is described back to the end of the last Interglacial (Ribains interglacial). The two Preglacial (early Glacial) forested interstadials (St-Geneys 1 and St-Geneys 2) are evidence for the first time in the Massif Central. In spite of the altitude of the site (1200 m), they suggest a quite temperate vegetation, with the same mesophilous character as during the Holocene. The Pleniglacial appears to be threefold, with two cold episodes (Lower and Upper Pleniglacial) divided by a long complex period of moderate climatic improvement. The vegetation history of this mountain region is compared with that evidenced for the same period on the basis of the sequence of Les Echets at a lower altitude (267 m). Botanical and climatic inferences are discussed. © 1990.