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

合作研究：东南印度洋中脊下方上地幔异质性的高分辨率、多同位素研究

• 批准号: 1029844
• 负责人: David Graham
• 金额: $ 18.4万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1029844&HistoricalAwards=false
• 关键词: Collaborative; Research; Resolution; Multi; Isotopic

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.

众所周知，地球地幔的熔化条件存在地理差异，这些差异与地幔温度和成分的差异有关。然而，这些变化与沿着大洋中脊喷发的熔岩成分之间的关系并不为人所知。这项研究的重点是分析化学的相似性和差异，在一组独特的紧密间隔的玄武岩样品，从130个地点沿沿着1200公里的脊顶的东南印度洋中。目标是确定海底熔岩在空间和时间上的变化程度，这种变化在这一部分海底是前所未有的，并将趋势与底层地幔过程联系起来。将对2009年在该地区进行国际考察时收集的样品进行He、Pb、Hf和Sr同位素分析。还将对40个样品进行He和He同位素以及CO2分析。这项工作的数据将与补充的地球化学数据（即，主要和微量元素）的国际科学家小组的工作样本。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，并建立科学基础设施。