Biostratigraphie et composition isotopique de Foraminifères planctiques des derniers 140000 ans dans la région de Minorque (Méditerranée occidentale) - BIOSTRATIGRAPHY AND PLANKTIC FORAMINIFERA STABLE ISOTOPE RECORDS OF THE LAST 140,000 YEARS IN THE WEST MEDITERRANEAN (MINORCA REGION)

Oxygen and carbon isotope records, fluctuation in the relative abundance of planktic foraminiferal species and faunal events (short intervals with G. conglobatus and right coiling G. truncatulinoides) in west Mediterranean sediments, suggest a permanent influx of Atlantic superficila waters during the last 140,000 years in this area. Oxygen isotopes changes during glacial interglacial cycles are amplified, relative to the open ocean, but with a lesser degree than in the East mediterranean. 13C values of G. ruber are on their whole higher than in the Atlantic but they display variations in opposited phases. Therefore they do not allow to retrace past variations in the atmospherici CO2. The microfaunal associations exhibit conditions dominantly cold. The G. conglobatus or right coiling G. truncatulinoides "events" are diachronous within the Mediterranean.