Fundamental Investigation of Glacial/interglacial Deep-sea pH and Carbonate Saturation Effects on Paired Benthic Foraminiferal Trace Element and Stable Isotope Signatures

深海有孔虫外壳中的微量元素和稳定同位素记录了它们钙化过程中的海洋环境信息。古海洋学家依靠这些有孔虫代用品来描述过去的环境条件（即，温度、盐度、冰川冰量）。我们假设，pH值的漂移，表现为在深海中的CO2浓度的变化，引起显着的变化，在底栖有孔虫生物矿化过程中，这反过来又会导致系统的微量元素和同位素paleoproxy校准的偏移。 我们建议测量的影响，pH值对金属纳入生物方解石生长在严格控制的环境条件下，在实验室中。 南卡罗来纳州大学拥有世界上唯一一个长期深海底栖有孔虫培养系统，专门用于实验性改变深海微量元素和pH值条件。选择实验pH值范围是为了代表深海中的化学物质，而不再现现场压力。该项目将扩大我们对与过去和现在深海化学有关的不同环境条件的替代反应的了解，并增进我们对动态海洋-大气系统的了解。它将直接支持至少两个研究生论文和两个本科科学专业，并将涉及传统上代表性不足的群体在科学本科和研究生水平。

Trace elements and stable isotopes incorporated into the shells of deep-sea foraminifera record information on the ocean environment during their calcification. Paleoceanographers depend on these foraminiferal proxies to characterize past environmental conditions (i.e., temperature, salinity, glacial ice volumes). We hypothesize that pH excursions, manifested by changing CO2 concentrations in the deep sea, induce significant changes in the benthic foraminiferal biomineralization process, which in turn can lead to systematic offsets of trace element and isotope paleoproxy calibrations. We propose to measure the effect that pH has on metal incorporation into biogenic calcite grown under stringently-controlled environmental conditions in the laboratory. The University of South Carolina maintains the only long-term deep-sea benthic foraminiferal culturing system in the world specifically designed to experimentally-vary deep-sea trace element and pH conditions. The experimental pH range is chosen to represent chemistries in the deep-ocean without reproducing in situ pressures. This project will broaden our understanding of proxy response to varying environmental conditions relevant to past and present deep-ocean chemistries and improve our knowledge of the dynamic ocean-atmosphere system. It will directly support at least two graduate student theses and two undergraduate science majors and will involve traditionally under-represented groups in science at the undergraduate and graduate levels.