Collaborative Research: A High-Resolution, Multi-Isotopic Study of Upper Mantle Heterogeneity Beneath the Southeast Indian Ridge

众所周知，在地球的地幔的融化条件有地理上的差异，这与地幔的温度和成分的差异有关。然而，这些变化与沿洋中脊喷发的熔岩的组成有何关系尚不清楚。本研究的重点是分析一组独特的玄武岩样品的化学相似性和差异性，这些样品来自印度洋东南印度洋脊脊1200公里脊顶的130个地点。目标是确定海底熔岩的时空变化，其程度在海底这部分是前所未有的，并将其趋势与潜在的地幔过程联系起来。在2009年对该地区进行的一次国际考察中已经收集的样品将被分析为He， Pb， Hf和sr的同位素。40个样品也将被分析为He和He同位素以及二氧化碳。这项工作的数据将与一个研究样品的国际科学家小组提供的互补的地球化学数据（即主要元素和微量元素）相结合。这项工作的更广泛影响包括与德国和法国科学家的国际合作以及研究和教育的整合。该项目涉及方法开发，这将促进实验室间分析校准，并为科学建立基础设施。

It is well known that there are geographic variations in the melting conditions in Earth's mantle and that these are tied to differences in mantle temperature and composition. How these variations relate to the composition of lavas erupted along mid-ocean ridges, however, is not well known. This research focuses on analyzing the chemical similarities and differences in a unique set of closely spaced samples of basalt from 130 localities along 1200 km of ridge crest of the Southeast Indian Ridge in the Indian Ocean. Goals are to determine the spatial and temporal variation of seafloor lavas to a degree that is unprecedented for this part of the seafloor and relate the trends to underlying mantle processes. Samples that are already in-hand and were collected on an international expedition to the area in 2009 will be analyzed for the isotopes of He, Pb, Hf, and Sr. Forty samples will also be analyzed for He and He isotopes and for CO2. Data from this work will be combined with complementary geochemical data (i.e., major and trace elements) from an international team of scientists working on the samples. Broader impacts of the work include international collaboration with German and French scientists and the integration of research and education. The project involves method development which will foster inter-laboratory calibration of analyses and builds infrastructure for science.