Collaborative Research: A SIMS and ICP-MS Calibration of Benthic Foraminiferal Elemental Chemistry

利用成对的元素和稳定同位素测量来重建过去的气候和水文变化一直在迅速增长，但对于底栖有孔虫，其可靠性仍有许多悬而未决的问题。根据该合同，PI将使用西姆斯和SEM技术对先前沿着小巴哈马银行南翼收集的OCE 205箱形岩心的保存分段进行取样，以确定其高Mg/Ca值的来源。 这些岩心被用来校准Mg/Ca温度高于约12摄氏度，但有证据表明，该方程没有重现附近的核心从佛罗里达海峡。西姆斯和ICP-MS将用于测量底栖有孔虫物种测试之间的变异性，并将活（染色）个体与最近的化石个体进行比较，以确定早期成岩作用在改变主要Mg/Ca信号方面的程度。清洁实验将显示化学处理如何影响有孔虫试验中镁的分布和数量。这项研究将有助于确定这一方法在应用于底栖有孔虫和深海水文学研究时是否合理。这项研究的结果将在课堂上和WHOI和CU的研究生培训，CU和海洋教育协会的本科生讲座，国际会议和同行评审期刊上发表。

The use of paired elemental and stable isotopic measurements to reconstruct past changes in climate and hydrology has been growing rapidly yet for benthic foraminifera there are still many outstanding questions about its reliability. Under this award the PIs will use SIMS and SEM techniques in samples from preserved subsections of OCE205 box cores previously collected along the southern flank of Little Bahamas Bank to determine the source of their high Mg/Ca values. These cores were used to calibrate Mg/Ca temperatures higher than about 12 degrees C but there is evidence that the equations are not reproduced in nearby cores from the Florida Straits. SIMS and ICP-MS will be used to measure the variability between tests of benthic foraminiferal species and to compare live (stained) individuals with recent fossil individuals to determine the extent of early diagenesis in altering the primary Mg/Ca signal. Cleaning experiments will show how chemical treatment may affect the distribution and amount of magnesium in the foraminiferal test. This research will help to determine the soundness of this approach when applied to benthic foraminifera and studies of deep ocean hydrography. The results of this study will be presented in classes and for graduate training at WHOI and CU, undergraduate lectures at CU and Sea Education Association, international conferences and peer reviewed journals.