THE GOUR-DE-TAZENAT AND THE LATE-GLACIAL TO BOREAL ENVIRONMENTAL-CHANGES IN THE NORTHERN CHAINE-DES-PUYS

A core taken from the lacustrine deposits of the ''Gour de Tazenat'', below 66 m of water, allowed us to describe the environmental changes from the early Late Glacial to the Boreal in the northern Chaine des P uys. The Middle Dryas is particularly well recorded and the Late Dryas can be subdivided into three cold sub-oscillations. The same sequence contains two tephra beds (volcanic ash): (i) one is mugearitic, dated at 10,280 a BP and within the Allerod; (ii) the other is trachytic, d ated at about 8,220 a BP and within the Boreal. The Tazenat volcano er upted prior to 29,000 a BP.