Assessing the Fidelity of Foraminiferal Mg/Ca- d18O to Estimate Seawater d18Or: A Multispecies Calibration-Validation Study

该项目将校准和验证贝壳衍生的d18 O海水的估计，已来自配对分析的Mg/Ca和d18 O在南极有孔虫对观察到的d18 O海水梯度的三个d18 O核心断面（亚）热带太平洋，大西洋和西北非洲边缘。此外，还将利用最近在葡萄牙和非洲西北部海域进行的一次取芯巡航期间收集的浮游生物拖丝和d18 O海水表层水样本进行现场d18 O海水校准。该研究将测试他在一系列58个岩心样品中观察到的“过量Mg/Ca”及其与盐度的明显联系的假设，可以在更大的（亚）热带海洋区域中分离和量化。本研究还将研究有孔虫壳形态，重量和壳镁/钙异质性与“过量镁/钙”端元样品的系统变化。该项目的更广泛的影响部分包括博士生的支持，参与和指导本科生的研究元素，以及一个转型级问题的研究，这是许多正在进行的古海洋学研究计划的基本组成部分。

This project will calibrate and validate shell-derived d18Oseawater estimates that have been derived from paired analyses of Mg/Ca and d18O in planktonic foraminifera against observed d18Oseawater gradients for three meridional coretop transects in the (sub)tropical Pacific, Atlantic, and NW African margin. In addition, an in situ d18Oseawater calibration will be conducted using plankton tow and d18Oseawater surface water samples collected during a recent coring cruise off the Portuguese and NW African margins. The research will test the hypothesis that the "excess Mg/Ca" that he has observed in a series of 58 coretop samples, and its apparent link to salinity, can be isolated and quantified over a larger (sub)tropical ocean domain. This research will also examine systematic changes in foraminifera shell morphology, weight, and shell Mg/Ca heterogeneity associated with "excess Mg/Ca" endmember samples. The Broader Impacts component of this project include support of a PhD student, involvement and mentoring of undergraduate students in elements of the research, and the study of a transformative-level problem that is a fundamental component of many ongoing paleoceanographic research programs.