First Comprehensive Sampling of the Shona and Discovery Seamount Chains, South Atlantic - Plume Versus Shallow Sources

摘要- 07518437（类别）智力价值：这项研究是一项大型国际合作的一部分，该合作旨在研究南大西洋绍纳和发现热点地区海底及其下方的地质和地球物理现象。尽管仅根据在大洋中脊玄武岩中测量到的地球化学特征就提出了Shona和Discovery地幔柱的存在，但尚未对一个或多个地幔柱进行验证。它们的存在是重要的，因为它们构成了大陆碱性岩浆活动模式的基础，例如南非含钻石的金伯利岩和次大陆岩石圈地幔的再循环和扩散。研究将集中分析从德国北极星号邮轮到南大西洋修纳岭-阿古拉斯岭-海角隆起和发现海山地区疏通的样本。这项资助的工作将需要分析海底火山岩的Sr-Nd-Hf-Pb同位素组成。这些数据将与多学科国际调查小组提供的主要和微量元素数据以及地球物理数据相结合。综合数据集将用于确定长期存在的绍纳羽的存在，或者，或者，绍纳和发现测深异常的大陆起源。更广泛的影响：这项工作的影响包括与德国、荷兰和南非的国际跨学科合作。它将支助一名女性职业研究人员，并帮助培训一名来自开普敦大学的研究生，该研究生将接受分析方法和进行独立研究的培训。资金还将用于为拉蒙特·多尔蒂地球天文台的同位素实验室提供必要的设备。

ABSTRACT - 07518437 (Class)Intellectual Merit: This research is part of a larger international collaboration to examine geological and geophysical phenomena of the seafloor and the phenomena beneath it in the South Atlantic in the area of the Shona and Discovery hotspots. Although the existence of Shona and Discovery mantle plumes has been suggested based solely on geochemical signatures measured in Mid-Ocean Ridge basalts, the verification of one or more mantle plumes has yet to be made. The presence of these are important because they form the basis of models of continental alkaline magmatism such as the South African diamond-bearing kimberlites and for the recycling and dispersal of subcontinental lithospheric mantle. Research will focus on the analysis of samples from dredged from the German Polarstern cruise to the Shona Ridge - Agulhas Ridge - Cape Rise and Discovery Seamount areas in the South Atlantic. The funded work will entail analyses of seafloor volcanic rocks for Sr-Nd-Hf-Pb isotopic compositions. These data will be integrated with major and trace element data and geophysical data from a multidisciplinary, international team of investigators. The integrated data set will be used to determine the existence of a long-lived Shona plume or, alternatively, a continental origin for the Shona and Discovery bathymetric anomalies. Broader impacts: Impacts of this work include international cross-disciplinary collaboration with Germany, The Netherlands, and South Africa. It will support a female career researcher and help train a graduate student from the University of Cape Town who will be trained in analytical methods and conduction of independent research. Funding also will help provide essential equipment to the isotope lab at Lamont Doherty Earth Observatory.