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

小达比9321487 该奖项支持继续对北冰洋活塞和箱式岩芯的沉积物进行沉积学研究。 该方法采用岩石学分析的岩屑，重矿物，反射光岩相学和铁不透明颗粒的微探针分析在北极周围的沉积物芯和潜在的源区的比较研究。 统计方法有助于比较沉积物岩心和潜在来源区的岩相学和化学数据，以确保沉积物和来源的最佳匹配，从而确定沉积物的来源。 以这种方式确定的沉积物源形成的基础上的推断运输途径和岩相学特征被用来推断运输机制。 这个项目将利用现有的材料以及1994年夏季北冰洋段航行期间收集的岩心。 其目标是：1）确定最近主要冰川和冰退事件的冰筏沉积物的来源，并推断过去18 000年期间北冰洋表面环流模式; 2）推断较早的冰筏事件的漂流模式; 3）评估俄罗斯河流中受污染沉积物的潜在分布，这些沉积物因海冰漂流而重新分布;（4）扩大北冰洋沉积物来源数据库。 这项工作是关于北冰洋沉积作用的基本信息，代表了对地质信息的重大投资，这对侧重于北极过去气候和最近活跃的地质过程的其他项目很有价值。 ***

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. ***