Multitracers to Predict Paleoproductivity in the California Current System from Sediment and Sediment Trap Materials

长期沉积物捕集器的部署为检验深海沉积物作为近表层海洋过程记录者的保真度提供了机会。这些研究是重要的，因为古海洋学研究的一个基本假设是，微古生物学和沉积物化学记录可以用来检查长期地质时间尺度上海面条件的变化。目前建议的奖金将支持对海洋沉积物中“输入”和“保存”关系的多示踪剂研究。稳定同位素、地球化学和微古生物学标准的使用应该能够准确地评估沉积沉积物和初始地表水输入之间的差异。该项目的现场阶段将在加利福尼亚洋流系统中部署一系列沉积物陷阱，该系统在净生产力和表面海洋学方面具有很强的季节性梯度。对沉积物圈闭物质和地表沉积物的分析将用于开发一套独立的净生产力代用物。最有可能提供这一信息的成分包括：生物、钙质和硅质微化石；重晶石和生物限制性微量元素，如铜和锌；有机物质和某些含氮化合物，包括碘、溴和磷。这样的分析应该能够准确地定义那些与净生物生产力高度相关的信号载体。主要研究人员具备承担该项目的实地和分析部分的高素质，并且已经成功完成了以前的沉积物圈闭项目。强烈建议按下列数额提供资金：87财政年度= $224 750；Fy88 = 229,615美元；Fy89 = 201,299美元。

Long-term sediment trap deployment provide an opportunity to examine the fidelity of deep-sea sediments as recorders of near- surface oceanic processes. Such studies are important because a fundamental assumption of paleoceanographic research is that the micropaleontologic and sediment chemistry record can be used to examine changes in sea surface conditions over long geologic time scales. The present recommended award will support a multitracer study of the relation of "imput" and "preservation" in marine sediments. The use of stable isotope, geochemical, and micropaleontologic criteria should allow an accurate assessment of differences between deposited sediments and the initial surface water input. The field phase of the project will deploy an array of sediment traps in the California Current system which has strong seasonal gradients in net productivity and surface oceanography. Analyses on the sediment trap material and surface sediments will be used to develop a set of independent proxies for net productivity. Components most likely to provide this information include: biogenous, calcareous, and siliceous microfossils; barite and bio-limiting trace elements such as copper and zinc; and organic matter and certain of its nitrogenous compounds including iodine, bromine, and phosphorous. Such analyses should allow an accurate definition of those signal carriers most highly correlated to net biologic productivity. The principal investigators are highly qualified to undertake the field and analysis portion of the project and have successfully completed previous sediment trap projects. Funding is strongly recommended at the following levels: FY87 = $224,750; FY88 = $229,615; FY89 = $201,299.