大洋钻探与全球变化(一)——南极地区显生宙晚期气候演变历史及对全球的影响

通过介绍Ｊ．Ｐ．Ｋｅｎｎｅｔｔ为代表的“洋流说”阐述了大洋钻探２５年来约１０个航次研究所揭示的南极地区显生宙晚期气候演变的历史。晚白垩世时南极地区和全球一样暖和无冰，末期变冷，古新世开始后不久又转暖，早始新世－中始新世早期达顶峰，以后变冷。渐新世为主要冷却期，南极东部形成冰盖，中，晚中新世为另一重要冷却期，南极西部以至全部南极在中新世晚期－上新世早期最终形成稳定冰盖。德雷克海峡打开，环南极洋流（Ａ

ODP AND GLOBAL CHANGES(I)-THE ANTARCTICA CLIMATE EVOLUTION DURING THE LATEST PHANEROZOIC AND ITS GLOBAL INFLUENCE

This article introduces a "current theory" represented by famous American paleoceanologist J. P. Kennett and expounds principal findings made by about 10 legs of Ocean Drilling Program (and its predecessor Deep Sea Drilling Project) investigations for the last 25 years concerning the Antarctic climate history during the latest Phanerozoic. The Antarctica was warm and ice-free during Late Cretaceous. The marked cooling occurred close to the end of Late Cretaceous accompanied with a mass extinction, then followed by a warming trend starting 0. 1 Ma after the K/T boundary,leading to the climate of Cenozoic warmth during the early to middle Eocene with the surface water temperature 15~16℃,even up to 20℃ and the bottom water temperature 12~14℃.After that important cooling steps occurred near the Eocene/Oligocene boundary, throughout the Oligocene, the middle-late Miocene,and the latest Miocene-earliest Pliocene. The cryospheric development commenced on East Amtarctica at the beginning of the Oligocene and the Antarctic continent was significantly "glaciated" during the Oligocene. Hence, the most important development was the formation of the West Antarctica ice-sheet during the late Miocene .The Antarctic ice-sheet was finally and stably formed in the latest Miocene-earliest Pliocene. Being probably induced by the opening of the Drake Strait, the formation of the Antarctic Circular Current(ACC) and Antarctic Bottom Water(AABW). All of these may give significant influence on the establishment of present global climate framework.