Collaborative Research: Deducing Late Neogene Antarctic Climate from Fossil-rich Sediments in the Dry Valleys

合作研究：从干燥山谷富含化石的沉积物中推断新近纪晚期南极气候

• 批准号: 0440761
• 负责人: Allan Ashworth
• 金额: --
• 依托单位: North Dakota State University Fargo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0440761&HistoricalAwards=false
• 关键词: Collaborative; Research; Deducing; Late; Neogene

This project studies ancient lake deposits from the western Dry Valleys of Antarctica. These deposits are particularly exciting because they preserve flora and fauna over seven million years in age that represent the last vestiges of ecosystems that dominated this area before formation of the modern East Antarctic ice sheet. Their unique nature offers a chance to bridge modern and ancient ecology. Formed along the margin of ancient alpine glaciers, these deposits contain layers of silt, clay, and volcanic ash; as well as freeze-dried remnants of mosses, insects, and diatoms. Geological and biological analyses provide a view of the ecological and environmental conditions during mid-to-late Miocene--seven to seventeen million years ago--which spans the critical period when the East Antarctic ice sheet transitioned to its present stable form. The results place the modern lakes of the Dry Valleys into a long-term evolutionary framework, and allow for correlation and dating comparisons with other fossil-rich deposits from the Transantarctic Mountains. Chemical fingerprinting and dating of volcanic glass shards will also help date fossil- and ash-bearing horizons in nearby marine cores, such as those to be collected under the ANDRILL program. The broader impacts are education at the postdoctoral, graduate, and undergraduate levels: and collaboration between a research institution and primarily undergraduate institution. The work also improves our understanding of global climate change during a critical period in the Earth's history.

该项目研究南极洲西部干谷的古代湖泊沉积物。这些沉积物特别令人兴奋，因为它们保存了超过700万年的植物群和动物群，这些植物群和动物群代表了现代东南极冰盖形成之前主导这一地区的生态系统的最后遗迹。它们独特的性质提供了一个连接现代和古代生态的机会。这些沉积物沿着古代高山冰川的边缘形成，含有淤泥层、粘土层和火山灰层，以及苔藓、昆虫和硅藻的冻干残留物。地质和生物分析提供了中新世中期至晚期（700万至1700万年前）的生态和环境状况，这一时期跨越了东南极冰盖过渡到目前稳定形式的关键时期。这些结果将干河谷的现代湖泊置于一个长期的演化框架中，并允许与跨南极山脉的其他富含化石的沉积物进行相关性和测年比较。火山玻璃碎片的化学指纹和年代测定也将有助于确定附近海洋岩心中含有化石和灰烬的地层的年代，例如根据ANDRILL计划收集的地层。更广泛的影响是博士后，研究生和本科生水平的教育：以及研究机构和主要本科院校之间的合作。这项工作还提高了我们对地球历史上关键时期全球气候变化的认识。