Luminescence Timing of Paleoenvironmental Changes in Quaternary Lake Sediments from the Arctic Taymyr Peninsula, Siberia

西伯利亚北极泰梅尔半岛第四纪湖泊沉积物古环境变化的发光时间

• 批准号: 9909686
• 负责人: Glenn Berger
• 金额: $ 7.5万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909686&HistoricalAwards=false
• 关键词: Luminescence; Timing; Paleoenvironmental; Changes; Quaternary

9909686BergThe arctic is a predicted highly sensitive region to future global climatic change, yet its harshness and remoteness have limited our knowledge of the geological record of past climatic/environmental changes in this region. The region of arctic Central Siberia is largely unexplored in this regard. German and Russian scientists have conducted geological, geochemical and geophysical studies over the last 6 years from the Taymyr Peninsula to the arctic islands of Severnaya Zemlya, on a south-north transect -1400 km long. Their objective has been to unravel the climatic and environmental history of northern Central Siberia over the last several tens of thousands of years. Long (up to -22 m) sediment cores have been recovered from several existing lakes, providing the most important paleoenvironmental data archive of the entire project, but they have proven to be difficult or impossible to date by the various radiocarbon procedures, mainly because of very low carbon concentration, or the presence of contaminating coal particles. The PI proposes to provide an alternative dating tool: infrared-stimulated-luminescence direct dating of the last exposure of sediment grains to daylight. Based on extensive experience with Alaskan and other North American lake cores, the PI will analyze in Reno about 29 lake-core samples with NSF support. Samples will first be collected (under separate funding) by the PI from a lake-core storage site in Potsdam, Germany. The proposed luminescence method has been shown to be accurate elsewhere, and with sediments much older than those expected in the Siberian lake cores. Luminescence dates are expected to provide the first direct, accurate chronology for these lake cores, and hence for the time series of several paleoenvironmental data sets already measured by German colleagues. These dates should also settle a controversy about the size (extent) of the last ice sheet (Eurasian Ice Sheet) in the area of central arctic Siberia. Glacial sediments are present in some of the lake cores, but the age of such sediments is unknown or highly speculative at present. Dating results are expected to provide also the first opportunity for across-Arctic-Ocean correlation to Quaternary pollen stratigraphies from Alaska that the PI has been involved with. Accurate time series of paleoenvironmental records from circum-arctic Quaternary sediments are essential for a fuller (quantitative) understanding of the past role of the arctic in global changes.

9909686Bergthe Arctic是未来全球气候变化的高度敏感区域，但其苛刻和远程性限制了我们对该地区过去气候/环境变化的地质记录的了解。 在这方面，西伯利亚北极中部地区在很大程度上没有探索。 在过去的六年中，从泰米尔半岛到西北北北区的Severnaya Zemlya岛，在过去的六年中，德国和俄罗斯科学家进行了地质，地球化学和地球物理研究。 他们的目标是揭开西伯利亚北部西伯利亚北部的气候和环境历史。 长期（高达-22 m）的沉积物核心已从现有的几个湖泊中回收，提供了整个项目中最重要的古环境数据档案，但是事实证明，它们很难或不可能通过各种放射性碳程序来约会，这主要是因为碳浓度非常低，或者存在非常低的碳浓度，或者存在污染燃料颗粒的存在。 PI建议提供一种替代的约会工具：红外刺激的亮度直接直接导致沉积物晶粒到日光下的最后一次暴露。 根据与阿拉斯加和其他北美湖核心的丰富经验，PI将在里诺分析大约29个湖核样本，并提供NSF的支持。 PI将首先从德国波茨坦的湖核存储地点（在单独的资金下）收集样品。 所提出的发光方法已显示出其他地方的准确性，并且沉积物比西伯利亚湖核心预期的要大得多。 预计发光日期将为这些湖泊核心提供第一个直接，准确的年代，因此，对于德国同事已经测量的几个古环境数据集的时间序列。 这些日期还应该解决有关北极西伯利亚中部最后一个冰盖（欧亚冰盖）的大小（范围）的争议。 冰川沉积物存在于某些湖泊岩心中，但目前这种沉积物的年龄是未知或高度投机的。 预计约会结果还将为来自阿拉斯加的第四纪花粉地层的全欧海洋相关性提供了第一个机会，PI已参与。 来自北极四季度沉积物的古环境记录的准确时间序列对于对北极在全球变化中的过去作用的更深入（定量）了解至关重要。