Dispersal History of Ice-Rafted Detritus in the Arctic Ocean (700KA to Present)

9321487 Darby 该奖项支持对北冰洋活塞和箱芯沉积物进行持续的沉积学研究。 该方法采用岩屑碎片、重矿物的岩相分析，以及反射光岩相学和不透明铁颗粒的微探针分析，对北极周围的沉积物岩心和潜在源区进行比较研究。 统计方法有助于比较沉积岩芯和潜在源区的岩相和化学数据，以确保沉积物和源区的最佳匹配，从而确定沉积物质的来源。 以这种方式确定的沉积物来源形成了关于传输路径的推断的基础，并且岩相特征用于推断传输机制。 该项目将使用现有材料以及 1994 年夏季北冰洋航段航行期间收集的岩芯。目标是 1) 确定最新重大冰期和冰消期事件的冰筏沉积物来源，并推断过去 18,000 年北冰洋表面环流模式； 2) 推断较早的冰漂流赛事的漂流模式； 3）评估俄罗斯河流受海冰漂流重新分布的受污染沉积物的潜在分布； 4) 扩大北冰洋沉积物来源的数据库。 这项工作是有关北冰洋沉积的基本信息，代表着对地质信息的重大投资，这对于关注北极地区过去的气候和近期活跃的地质过程的其他项目来说非常有价值。 ***

9321487 Darby This award supports a continued sedimentological study of sediment from piston and box cores from the Arctic Ocean. The method employs petrographic analysis of lithic fragments, heavy minerals, and reflected light petrography and microprobe analysis of iron- opaque grains in a comparative study of sediment cores and potential source areas around the Arctic. Comparison of the petrographic and chemical data from the sediment cores and potential source areas is facilitated by statistical methods to ensure best-fit matches of sediment and source for determining the origin of sedimentary material. Sediment provenance determined in this way forms the basis of inferences about transport pathways and the petrographic characteristics are used to infer transport mechanisms. This project will use existing material as well as cores to be collected during the Arctic Ocean Section cruise in the summer of 1994. The goals are to 1) determine the source of ice-rafted sediment for the latest major glacial and deglacial events and to infer Arctic Ocean surface circulation patterns during the last 18,000 years; 2) infer the drift patterns for older ice-rafting events; 3) assess the potential distribution of contaminated sediment from Russian rivers which are redistributed by sea-ice rafting; and 4) expand the database from which sediment provenance for the Arctic Ocean is derived. This work is basic information about sedimentation in the Arctic Ocean and represents a significant investment in geologic information that will be valuable for other projects focusing on past climates and recent geologic processes active in the Arctic. ***