Joides-Resolution visited the Weddell Sea from January 5 to March 11, 1987. Twenty-two holes were drilled at nine sites, and allowed us: (1) to find the evidence of strong cooling duringthe early Oligocene in East Antarctica, during the middle Miocene in West Antarctica; (2) todemonstrate the presence of ice during the Oligocene in East Antarctica, during the early late Miocene in West Antarctica; and (3) to establish the age of formation of the ice-sheets, during the middle Miocene in East Antarctica, during the late Miocene in West Antarctica, and provide evidence of theirstability since the first stages of their development