ABR: Siliceous Paleoceanography: (Ge/SI)opal - IV

9315110 Froelich在我们了解海洋硅藻对Ge/Si的轻微生物分馏方面的最新进展表明，在晚更新世活塞芯和新生代钻芯中测量到的Ge/Si的蛋白石变化记录了由于大陆风化强度和河流入海通量的快速和大范围冰川至间冰期变化所引起的全海洋(Ge/Si)海水变化。如果是这样的话，显然重要的是在岩心中产生高分辨率的(Ge/Si)蛋白石记录，并在转变过程中建立良好的18O和14C地层学，以确定相对于其他气候和风化指标的海洋Ge/Si响应的形状和时间。此外，面对微小的生物分馏效应，为了解决整个海洋的变化，有必要仔细评估和消除地方志中Ge/Si分馏的影响。随着快速、高灵敏的氢化物发生-电感耦合等离子体质谱-GE-方法的发展，这些问题可以得到解决，并且可以开始解开原因和时间以及海洋化学变化。因此，这项工作旨在实现两个主要目标：(1)在含有丰富硅藻和有孔虫的岩心中产生高分辨率的晚更新世(Ge/Si)蛋白石记录；(2)与其他人对同一岩心(例如87Sr/86Sr)适当的古地球化学示踪剂的测量合作，提供测试，以完善硅藻培养、水文和岩心顶部断面以及汉堡大洋Ge/Si模型的运行的Ge/Si生物分馏的影响。此外，还将继续在南极(扩展到北太平洋和南太平洋)开展蛋白石古生产力工作，以及其他辅助方案。

9315110 FROELICH Recent advances in our understanding of minor biological fractionation of Ge/Si by oceanic diatoms suggest that Ge/Si)opal variations measured in late Pleistocene piston cores and Cenozoic drill cores are recording whole ocean (Ge/Si)seawater variations driven by rapid and large glacial to interglacial changes in continental weathering intensity and river fluxes to the sea. If so, then it is clearly important to produce high resolution records of (Ge/Si)opal in cores with well-established 18 O and 14C stratigraphies across transitions to establish the shape and timing of the oceanic Ge/Si response relative to other climate and weathering indicators. In addition, in order to resolve whole ocean changes in the face of small biological fractionation effects, it is necessary to carefully evaluate and remove the effects of Ge/Si fractionation in local records. With the development of a rapid and highly-sensitive HG-ICP-MS Ge-method, these problems can be addressed and unraveling the causes and timing and ocean chemical variations can begin. As a result, this is aimed at accomplishing two major goals: (1) Produce high resolution late Pleistocene (Ge/Si)opal records in cores that contain abundant diatoms and forams in collaboration with others' measurements of the appropriate paleogeochemical tracers in the same cores (e.g. 87Sr/86Sr); and (2) Provide tests to refine the effects of Ge/Si biological fractionation with diatom cultures, hydrographic and core top transects, and runs of the Hamburg ocean Ge/Si model. In addition, opal paleoproductivity work in the Antarctic (expanding into the North and South Pacific Oceans), and other ancillary programs will be continued.