This study, supported by the Observatoires Volcanologiques de l'Institut de Physique du Globe de Paris and by the Centre National de la Recherche Scientifique (C.N.R.S.) programs, is a contribution to the geochronology of the recent volcanic events of the South of the Basse-Terre of Guadeloupe (Lesser Antilles). Three methods were adopted : 1) K/ Ar dating adapted for ages less than 1 m.y. was used to obtain ages on basaltic to andesitic lava flows of the Pitons de Bouillante - Sans Toucher cycle , of Monts Caraïbes and of the initial phase of the early cycle of Madeleine -Soufrière . 2) Thermoluminescence studies on quartz were used for dating some dacitic pumice layers of the Chaîne andésitique de Bouillante cycle and the early cycle of Madeleine - Soufrière. 3) whole- rock analyses of major and trace elements ( La, Th, Sc, Co) and microprobe analyses of phases were used to geochemically characterize the different pumice layers and to regroup these layers into their most likely cycle, and to record evidence for magma mixing. The results obtained enable the geochronology to be modified as follows : - the end of the cycle of the Pitons de Bouillante - Sans Toucher occurred at about 600 000 years, - the end of the Chaîne andésitique de Bouillante occurred at approximately 244 000 years, - the start of the activity of the Monts Caraïbes cycle took place at about 500 000 years. The most important result concerns the start of the recent Madeleine - Soufrière cycle for which a volcanic phase "the phase Carmichael" was dated at between 150 000 and 100 000 years; its activity began with an explosive episode (quartz pumice of the Anse des Pères and andesitic pumice of Pintade) and was followed by a very important effusive episode (flows of the north and south groups of Trois Rivières ) . Between the end of the phase Carmichaël and the start of the phase Madeleine, was a period of quiescence lasting about 70 000 years.
