Glacial climates in the Antarctic region during the late Paleogene: Evidence from northwest Tasmania, Australia.

Published data suggest that ice buildup commenced in Antarctica during the late middle Eocene. This predates by 30 m.y. the earliest evidence of Cenozoic glaciation on other fragments of Gondwana, although several of these were at high latitudes during the Paleogene. We provide new evidence for local glacier development during the late Paleogene in Tasmania, then a mountainous peninsula at about lat 55°-63°S projecting into the circum-Antarctic ocean. The date of glaciation is not precisely known, but an earliest Oligocene age is indicated. We suggest that episode may correlate with abrupt cooling of the sea surface surrounding Antarctica during the earliest Oligocene (36 Ma).