Accurate Calibration of Multiple Paleoceanographic Proxies in Benthic Foraminifera

根据该合同，pi将在几种底栖有孔虫物种中校准多种古海洋地球化学指标。本工作将对底栖有孔虫地球化学指标的认识和应用具有重要意义。由于这些测量构成了许多古气候研究的基础，因此改进的校准是必要的，并将得到广泛应用。代理包括温度和盐度（Mg/Ca, d18O），营养成分（Cd/Ca, Zn/Ca, d13C）， pH （d11B）以及可能的碳酸盐离子浓度（U/Ca, Li/Ca）的估计值。2002年，专门为此目的，在佛罗里达州和古巴之间的38个地点收集了一系列多核顶部和海水样本。这个集合代表了一个独特的校准机会，有几个原因：(1)丰富的底栖有孔虫，高沉积速率和大量收集的沉积物允许对近现代标本进行多次测量；(2)位点在目标参数的大范围内（如15℃，1.9 psu, 0.24 pH）；(3)从安装在多层盖上的Niskin瓶中收集的海水可以准确地测定现场的水条件，即盐度、d18O、元素浓度和碳酸盐系统参数（随附的CTD铸件可获得准确的温度）。

Under this award the PIs will calibrate multiple paleoceanographic geochemical proxies in several species of benthic foraminifera. This work should contribute significantly to the understanding and application of benthic foraminiferal geochemical proxies. Since such measurements form the foundation of many paleoclimatic studies, improved calibrations are essential and will be widely employed. Proxies include estimators for temperature and salinity (Mg/Ca, d18O), nutrient content (Cd/Ca, Zn/Ca, d13C), pH (d11B), and possibly carbonate ion concentration (U/Ca, Li/Ca). A series of multicore tops and seawater samples were collected from 38 locations between Florida and Cuba in 2002, expressly for this purpose. This collection represents a unique calibration opportunity for several reasons: (1) abundant benthic foraminifera, high sedimentation rates, and large volumes of collected sediment allow for multiple measurements of near-modern specimens; (2) the sites span large ranges of the targeted parameters (e.g., 15 C, 1.9 psu, 0.24 pH); and (3) seawater collected from a Niskin bottle mounted on the multicorer provides accurate determinations of in-situ water conditions, namely salinity, d18O, elemental concentrations, and carbonate system parameters (accurate temperatures are available from accompanying CTD casts).