Enhancing Holocene Ice Sheet and Ice Shelf Geochronology using Geomagnetic Paleointensity Variations

利用地磁古强度变化增强全新世冰盖和冰架地质年代学

• 批准号: 0838331
• 负责人: Stefanie Brachfeld
• 金额: $ 11.94万
• 依托单位: Montclair State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838331&HistoricalAwards=false
• 关键词: Enhancing; Holocene; Ice; Sheet; Shelf

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on constructing a geomagnetic relative paleointensity (RPI) and paleosecular variation (PSV) record from Maxwell Bay, South Shetland Islands, using the Shallow Drilling (SHALDRIL) 108-m core that was collected in 2005 during the cruise of the USAP research ship Nathaniel B. Palmer. This core has the unique combination of a radiocarbon chronology constructed entirely from biogenic calcite dates and a homogeneous silty-clay lithology that is ideal for paleomagnetic studies. This combination is rarely found in Antarctic continental shelf sediments. The RPI and PSV records from the Maxwell Bay core will serve as regional reference curves for tuning and dating records of ice sheet, ice shelf, and glacier history on both sides of the northern Antarctic Peninsula that lack their own independent age control. The use of paleointensity curves for millennial-scale correlation and dating via tuning with a reference curve has been successfully applied around the globe, and could provide a much-needed additional geochronology tool for the Antarctic. As one of the very few independently dated RPI and PSV records from high southern latitudes, this record will also be valuable for inclusion in geomagnetic field models that seek to understand the time-varying behavior of the geodynamo. The PSV and RPI datasets will be made publicly available through the Magnetics Information Consortium (MagIC) paleomagnetic database.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目的目的是利用2005年USAP研究船Nathaniel B巡航期间收集的108米浅钻岩心，建立南设得兰群岛麦克斯韦湾的地磁相对古强度（RPI）和古长期变化（PSV）记录。帕尔默该岩心具有完全由生物成因方解石测年构建的放射性碳年代学和非常适合古地磁研究的均匀粉质粘土岩性的独特组合。这种组合在南极大陆架沉积物中很少发现。来自麦克斯韦湾岩心的RPI和PSV记录将作为区域参考曲线，用于调整和测年缺乏独立年龄控制的北方南极半岛两侧的冰盖、冰架和冰川历史记录。利用古强度曲线进行千年尺度的对比和通过参照曲线调整测年已在地球仪成功应用，并可为南极提供急需的额外地质年代学工具。作为极少数来自南半球高纬度地区的独立定年的RPI和PSV记录之一，这一记录也将是有价值的地磁场模型，试图了解随时间变化的行为的地球发电机。PSV和RPI数据集将通过磁性信息联盟（MagIC）古地磁数据库公开提供。