Collaborative research: Water stratigraphy of the oceanic lithosphere using mantle xenoliths from Hawaii

合作研究：利用夏威夷地幔捕虏体进行海洋岩石圈水地层学

• 批准号: 1129280
• 负责人: Michael Bizimis
• 金额: $ 12.06万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129280&HistoricalAwards=false
• 关键词: Collaborative; research; Water; stratigraphy; oceanic

The funded project provides the first set of measurements of the H2O content of the oceanic mantle and involves collaboration between an academic institution and a private sector firm that has a unique capability to measure H2O in igneous minerals (high-resolution FTIR). The importance of this work lies in the fact that small differences in mantle H2O content can have profound effects on mantle rheology and seismic structure, both of which can impact magma generation and crustal movement and have implications for our understanding and prediction of geohazards. Because the mantle is not directly accessible, the investigators implemented a clever approach in which H2O will be measured in minerals coming from pieces of mantle rock (i.e., xenoliths) that were ripped up during the eruption and upward migration of magma of Hawaiian volcanoes. Using compositional relations of mineral pairs that indicate the depth at which the minerals formed, the depth of origin of the various xenoliths that are to be studied can be determined. Using these, the H2O content of the minerals will be examined by Fourier Transform Infra Red (FTIR) spectroscopy. Xenoliths distributed over 300 km along the Hawaiian Island chain and mantle depths to up to 100 km will be analyzed. Broader impacts of the work are robust and multifaceted. A major impact of the project is the provision of essential data that is needed to better interpret the seismic structure of the ocean crust, which will impact our ability to better model the source areas of geohazards like volcanoes and subduction zone earthquakes. The work also supports collaboration between a public university in an EPSCoR state and private industry. It also has a significant component of in-service teacher training where high school teachers in South Carolina work in the laboratory of the lead PI during the summer, getting a chance to engage in frontline research with academic scientist. The teacher?s research will form the basis for classroom and K-12 instructional materials. Workforce training will be carried through the involvement of graduate and undergraduate students in state-of-the-art geochemical analytical techniques. The Program notes that the graduate student is from a group under-represented in the science.

该资助项目提供了第一套海洋地幔水含量的测量方法，涉及一个学术机构和一家私营公司之间的合作，该公司具有测量火成岩矿物中水的独特能力（高分辨率FTIR）。这项工作的重要性在于，地幔水含量的微小差异可以对地幔流变学和地震结构产生深远的影响，这两者都可以影响岩浆的产生和地壳的运动，并对我们对地质灾害的认识和预测具有重要意义。由于地幔不能直接进入，研究人员采用了一种聪明的方法，即在夏威夷火山喷发和岩浆向上迁移期间被撕裂的地幔岩石碎片（即捕虏体）中的矿物质中测量H2O。利用表明矿物形成深度的矿物对的组成关系，可以确定要研究的各种捕虏体的起源深度。利用这些，矿物的水含量将被傅里叶变换红外光谱（FTIR）检查。捕虏体沿夏威夷岛链分布超过300公里，地幔深度可达100公里。这项工作的广泛影响是强有力的和多方面的。该项目的一个主要影响是提供了更好地解释海洋地壳地震结构所需的基本数据，这将影响我们更好地模拟火山和俯冲带地震等地质灾害源区的能力。这项工作还支持EPSCoR州内公立大学与私营企业之间的合作。它也有在职教师培训的重要组成部分，南卡罗来纳州的高中教师在夏季期间在首席PI的实验室工作，有机会与学术科学家一起从事前沿研究。老师吗?他的研究将成为课堂和K-12教学材料的基础。劳动力培训将通过研究生和本科生参与最先进的地球化学分析技术来进行。该项目指出，该研究生来自一个在科学领域代表性不足的群体。