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

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)提供资金的。该项目旨在利用2005年在USAP科考船纳撒尼尔·B·帕尔默巡航期间收集的浅层钻探(SHALDRIL)108米岩心，建立南设得兰群岛麦克斯韦尔湾的地磁相对古强度(RPI)和古分子变化(PSV)记录。该岩心具有完全由生物方解石年代构建的放射性碳年代学和均匀的粉质粘土岩性的独特组合，这是古地磁研究的理想之选。这种组合在南极大陆架沉积物中很少见。来自Maxwell Bay岩心的RPI和PSV记录将作为区域参考曲线，用于调整和测定南极半岛北部两侧缺乏独立年龄控制的冰盖、冰架和冰川历史的记录。利用古强度曲线进行千年尺度的对比和测年，通过与参考曲线调谐，已在全球范围内成功应用，并可能为南极提供急需的额外地质年代学工具。作为南方高纬度地区为数不多的独立确定RPI和PSV日期的记录之一，这一记录对于将其纳入试图了解地球发电机随时间变化的行为的地磁场模型中也将是有价值的。PSV和RPI数据集将通过磁学信息联合会(MAGIC)古地磁数据库公开提供。

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.