Collaborative Research: Mantle Plume Dynamics and Noble Gases Isotope Systematics Along the Mid-Atlantic Ridge

这是罗彻斯特大学和罗德岛大学之间的一项合作研究，使用多种同位素示踪剂来研究热浮力地幔柱与沿大西洋中脊（79 N -6 S）枯竭的软流层相互作用时的放气动力学。该提案将侧重于稀有气体（He, Ne, Ar, Xe）的同位素分析和元素的父/子浓度（Rb/Sr, Sm/Nd, U/Pb， Th/Pb和Cl）。在精心挑选的MORB玻璃上，将建立一个完整的多同位素和浓度数据集，用于不同挥发性的元素，从Sr， Nd，Pb到He，Ne, Ar， Xe和Cl。通过将挥发性和亲石性同位素测量与地球物理数据相结合，本研究将试图约束地幔柱的放气行为，地幔非均质性的性质、尺度长度和混合特征以及地幔柱-软流圈混合动力学。调查的四个省份分别是：赤道大西洋、扬马扬-莫恩斯-尼波维奇海岭、冰岛-雷克雅斯-科尔拜西海岭和亚速尔-中大西洋海岭。每个区域都有独特的地球化学和构造特征，这将为地幔演化和地幔柱动力学提供见解。

9301602 Poreda This proposal is a collaborative research effort between the University of Rochester and the University of Rhode Island to use multiple isotopic tracers to investigate the dynamics of outgassing when thermally buoyant mantle plumes interact with the depleted asthenosphere along the Mid-Atlantic Ridge (79 N -6 S). This proposal will focus on the isotopic analyses of the noble gases (He, Ne, Ar, Xe) and on the elemental parent/daughter concentrations (Rb/Sr, Sm/Nd, U/Pb, Th/Pb and Cl). On hand-picked MORB glass, a complete multi-isotope and concentration data set will be established for elements of varying volatilities, ranging from Sr, Nd,Pb to He,Ne, Ar, Xe and Cl. By combining both volatile and lithophile isotope measurements with geophysical data, this research will attempt to constrain the outgassing behavior of mantle plumes, the nature, scale length and mixing characteristics of mantle heterogeneities and the dynamics of plume-asthenosphere mixing. The four provinces of investigation are: the Equatorial Atlantic, the Jan Mayen-Mohns-Knipovich Ridge, the Iceland-Reykjanes-Kolbeinsey Ridge and the Azores-Mid Atlantic Ridge . Each region has unique geochemical and tectonic characteristics that will provide insights into mantle evolution and plume dynamics.