Evidence for Deepwater Circulation Changes in the Late Quaternary from the Nd Isotope Composition of Ferromanganese Precipitates in Marine Sediments

小行星9809253 该项目将分析跨越末次冰期/间冰期循环的大西洋沉积物中铁锰沉淀物中的Nd同位素。作者认为，Nd作为深水循环的示踪剂具有优势，因为它不受生物过程的影响。 将在开普盆地、格兰德河海隆、塞阿拉海隆和布莱克-巴哈马-百慕大海隆地区分析跨越北大西洋深水和南极底层水现代范围的岩心深度剖面。 同位素比率将与已知的水柱值进行比较，矿物学和地球化学测试将用于制定识别未蚀变物质的标准。 将对冰期和间冰期的样本进行比较，以评估以前通过其他技术得出的深水循环的推断。

9809253 Hemming This project will analyze Nd isotopes in ferromanganese precipitates from Atlantic Ocean Sediments spanning the last glacial/interglacial cycle. The authors propose that Nd offers advantages as tracer of deepwater circulation because it is unaffected by biologic processes. Depth transects of cores spanning the modern ranges of North Atlantic Deep Water and Antarctic Bottom Water will be analyzed in the Cape Basin, The Rio Grande Rise, the Ceara Rise, and the Blake-Bahama-Bermuda Rise regions. Isotopic ratios will be compared with known water-column values, and mineralogic and geochemical tests will be used to develop criteria to identify unaltered material. Samples from glaical and interglacial periods will be compared to assess previous inferences of deep water circulation derived by other techniques.