Antarctic climate history at the onset of glaciation: Was there ice in the greenhouse?

在大约5000万年前的极端温暖的全球“温室”时期，南极洲大部分是无冰的，并拥有温带森林。随后数百万年的冷却导致了始新世末南极气候的持续恶化，最终在渐新世（约3400万年前）开始时大范围的冰川作用达到顶峰。人们对冰盖形成之前的气候变化和温室期间冰川甚至小冰盖的可能存在都有争议。最近的研究支持冰川活动导致主要的冰川作用，但有争议的是，该项目将通过应用现有的沉积学、矿物学和地球化学方法，沿着用于重建南极古气候及其随时间变化的新代用指标和岩心成像方法的发展和应用。该项目将重点调查即将到来的国际海洋发现计划（IODP）第379次南极洲西部阿蒙森海考察（2019年1月至3月）中将要恢复的新岩芯序列，并结合对过去科学钻探项目中分布在南极边缘的现有岩芯的研究。

During the extremely warm global 'greenhouse' period ~50 million years ago, Antarctica was mostly ice free and hosted temperate forests. Subsequent cooling over many millions of years resulted in a steady deterioration of Antarctic climate at the end of the Eocene Epoch, eventually culminating in widespread glaciation at the beginning of the Oligocene Epoch (~34 million years ago). Both climate variability prior to ice-sheet development and possible existence of glaciers, or even small ice sheets, during greenhouse intervals are debated. Recent studies support glacial activity in the lead up to major glaciation, but, controversially, more substantial ice cover in East Antarctica during earlier (and warmer) time intervals of the Eocene has also been interpreted.This project will gain new insight into the early climate history of Antarctica through application of established sedimentological, mineralogical, and geochemical methods, along with development and application of novel proxy and core imaging methods for reconstructing Antarctic palaeoclimates and variations through time. The project will focus on the investigation of new drillcore sequences to be recovered on upcoming International Ocean Discovery Program (IODP) Expedition 379 to the Amundsen Sea, West Antarctica (Jan-Mar 2019), combined with study of existing drillcores distributed around the Antarctic margin from past scientific drilling projects.