Neogene Palynology from Antarctic Marine and Glacial Sediments

该奖项支持了一项对中国晚新生代植被的研究， 利用冰碛物和海洋植物的孢粉学研究南极山脉 沉积物 南极洲的陆地植被记录 自大约40 Ma（Ma =百万年）冰川作用开始以来 在此之前，人们对它知之甚少。 它被认为是 在渐新世晚期冰川作用期间从南极洲驱逐（30 中中新世时期（15Ma）已消失。 然而，在这方面， 保存完好的假山毛榉属的枝条、叶子、根和花粉 （南方山毛榉）和针叶花粉现在已知从 上新世中上部天狼星群（南纬86度，海拔1800米 海拔高度）。 Nothofaguso生存 直到上新世晚期，至少意味着新第三纪气候为15 °至 比现在高20摄氏度，即使在冰河时期。 基于 一种解释是，目前寒冷的极地气候开始， 植物的生长和现在冰盖的生长都发生在 在过去的三年里。 如果那些需要平均夏季的植物 温度高于5oC，生长在高海拔（1500米）， 那么一片茂盛的植被应该 生长在海平面上，应该产生丰富的花粉 记录在上新世海岸沉积物中。 本研究的目标 是为了了解晚新生代的植被历史， 大陆，从而限制模型的历史， 南极冰盖和解决上新世问题 南半球变暖。

This award supports a study of late Cenozoic vegetation in the Transantarctic Mountains using palynology of tills and marine sediments. The record of terrestrial vegetation in Antarctica since the onset of glaciation at about 40 Ma (Ma = million years before present) is poorly known. It was thought to have been expelled from Antarctica during a late Oligocene glaciation (30 Ma), and certainly lost by middle Miocene time (15 Ma). However, well-preserved twigs, leaves, roots, and pollen of Nothofagus (southern beech) and coniferous pollen are now known from the mid- to upper Pliocene Sirius Group (86oS latitude; 1800m above sea level) in the Transantarctic Mountains. Nothofaguso survival until at least the late Pliocene implies a Neogene climate 15o to 20oC warmer than today, even during glacial periods. Based on one interpretation, onset of the present cold polar climate, loss of the plants, and growth of the present ice sheet all occurred within the last 3 Ma. If the plants, which require mean summer temperatures warmer than 5oC, grew at high elevations (1500m) in the Transantarctic Mountains, then a lush vegetation should have grown at sea-level which should have produced a rich pollen record in Pliocene coastal sediments. The goals of this study are to understand the late Cenozoic vegetation history of the continent and thereby to constrain models for the history of the Antarctic ice sheets and to resolve the question of Pliocene warming in the southern hemisphere.