Friis Hills Drilling Project: An International Collaboration to Examine the Miocene Transition in Antarctica

南极洲的科学钻探使科学家能够收集有关过去全球气候变化时期的详细信息。以前针对海洋沉积物的钻探项目表明，南极洲在大约1500万年前经历了一次重大的冷却事件。 先前对位于南极洲干旱山谷的弗里斯山表层沉积物的研究表明，1500万年前的这一转变使南极洲从植被环境转变为冰川环境。 该项目的目标是弗里斯山的陆地钻探地点，以收集可与海洋沉积物岩心和表层沉积物相比较的保存完好的古老湖泊沉积物岩心。 从核心和表面沉积物的火山灰层可以定年和相关的限制在南极洲的气候转变的时间。海洋和湖泊沉积物岩心的综合数据集将使科学家们对过去的气候事件有一个更完整的了解，因为他们比较了南极大陆广泛的陆上-海上断面的环境数据。由这个快速反应研究（RAPID）项目支持的美国调查人员将加入来自新西兰和意大利的研究小组，进行钻探并收集多个湖泊沉积物岩心。这一新的数据集将提供南极陆地上最古老的连续沉积记录，从而有助于回答长期存在的地理学问题，包括：（1）新近纪冻原生物群何时灭绝？(2)是气候变化导致了生物的单向性和永久性的更替？还是支持苔原的短暂、温暖的气候条件在中新世中期之后又回到了干旱山谷？(3)是否有任何可能的温暖条件在其范围内的区域或大陆？(4)西部干旱河谷地区新近纪气候演化和新近纪景观演化的记录有多密切的联系？ 该项目的美国参与者负责实现以下目标：（1）通过对弗里斯山岩芯中发现的火山灰层中的晶体进行40 Ar/39 Ar定年，建立弗里斯山岩芯的年代学;（2）将已发表的地表沉积物露头记录与即将公布的弗里斯山岩芯地层学相关联;（3）描述弗里斯山的小气候特征，以供未来冰盖和气候建模计划使用。该项目使早期职业研究人员受益，并为研究生提供培训。成果和产品的传播将通过同行评议的出版物和会议摘要进行，并将在马萨诸塞州伍斯特州立大学的新舌ticKids项目中突出显示，该项目旨在吸引K-8学校的学生学习科学。

Scientific drilling in Antarctica allows scientists to gather detailed information about past periods of global climate variability. Previous drilling projects that targeted marine sediments have shown that Antarctica experienced a major cooling event about 15 million years ago. Previous studies of surface sediments in the Friis Hills, located in the Dry Valleys of Antarctica, suggested that this transition at 15 million years ago shifted Antarctica from a vegetated to a glaciated environment. This project is targeting terrestrial drilling sites in the Friis Hills to collect cores of ancient and well-preserved lake sediment that can be compared to the marine sediment cores and surface deposits. Volcanic ash layers from the core and surface deposits can be dated and correlated to constrain the timing of climate transition in Antarctica. The combined data set of the marine and lake sediment cores will give scientists a more complete picture of past climate events as they compare environmental data across a broad onshore-offshore transect for the Antarctic continent. The US investigators supported by this RAPID (Rapid Response Research) project will join a research team from New Zealand and Italy to conduct the drilling and collect multiple lake sediment cores. This novel dataset will provide the oldest continuous sedimentary record in the terrestrial Antarctic and thus help to answer long-standing questions of biogeography including: (1) When did the Neogene tundra biota become extinct? (2) Was the climate change that caused the biotic turnover unidirectional and permanent; or, did short-lived, warmer-climatic conditions that supported tundra, return to the Dry Valleys after the mid-Miocene? (3) Were any possible warmer conditions regional or continental in their extent? (4) How closely linked are the records for Neogene climate evolution and Neogene landscape evolution in the western Dry Valleys region? The U.S. participants in this project are responsible for the following objectives: (1) establish chronology of the Friis Hills core by 40Ar/39Ar dating of crystals from ash layers found in the core, (2) correlate the published outcrop record from surface sediments to the forthcoming Friis Hills core stratigraphy, and (3) characterize the microclimate of Friis Hills for future ice sheet and climate modeling initiatives. The project benefits an early career researcher and provides training for a graduate student. Dissemination of results and products will be via peer-reviewed publications and conference abstracts and will be highlighted in the novel AntarcticKids program at Worcester State University, MA, aimed at attracting K-8 school students to science.