Boundary Nature of the DUPAL Anomaly in the South Atlantic

地幔中两大地球化学省的分界线位于南大西洋。以印度洋为中心的区域被称为DUPAL异常区。这种异常可能是由于冈瓦纳大陆分裂和分散期间次大陆岩石圈的分层或地球内部更深起源的地幔柱的分散而污染了大气。该项目将对南大西洋海底的盐进行Nd-Sr-Pb同位素和微量元素研究，以便在时间和空间上确定南大西洋DUPAL省的同位素和地球化学性质。首席研究员将进一步分析他收集的南大西洋玄武岩，以获得：已获得Pb、Sr和He同位素数据的同一玻璃样品上的Nd同位素比率，同一玻璃样品上的父/子浓度比率，以及更古老玄武岩上的Nd-Sr-Pb系统，以记录时间地幔变化。

The boundary between two major geochemical provinces in the earth's mantle lies in the South Atantic. The province centered over the Indian Ocean is referred as the DUPAL anomaly. This anomaly may be the result of contamination of the asthemosphere either by delamination of sub-continental lithosphere during the breakup and scatter of Gondwanaland or from the dispersal of mantle plumes of deeper origin within the Earth. This project will undertake a Nd-Sr-Pb isotope and trace element study of asalts from the South Atlantic seafloor to define in time and space the isotopic and geochemical nature of the DUPAL province in the South Atlantic. The principal investigator will further analyze his collection of South Atlantic basalts to obtain: Nd isotopic ratios on the same glass samples on which Pb,Sr, and He isotope data are already available, parent/daughter concentration ratios on the same glass samples, and Nd-Sr-Pb systematics on older basalts in order to document temporal mantle variations.