Sr, Nd, Pb and Hf isotopes of basalts from the Quebrada/Discovery/Gofar transform fault system;key to test models of melt generation,transport and focusing beneath mid-ocean ridges

克布拉达/发现/戈法尔转换断层系统玄武岩的 Sr、Nd、Pb 和 Hf 同位素；测试大洋中脊下熔体生成、传输和聚焦模型的关键

• 批准号: 1355932
• 负责人: Alberto Saal
• 金额: $ 13.79万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2016-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1355932&HistoricalAwards=false
• 关键词: Sr; Nd; Pb; Hf; isotopes

Mid-ocean ridges are associated with the largest number of active volcanoes and volcanic features on Earth. Understanding how magmas erupting on the seafloor form and from what depths and parent compositions/lithologies they are sourced, is critical for being able to predict and model complex crustal processes. This research will complete the geochemical characterization of an important suite of lavas collected from the East Pacific Rise in the Central Pacific Ocean by producing the Sr, Nd, Pb, and Hf isotopic compositions of over eighty lavas from the Quebrada/Discovery/Gofar transform fault system. The isotope data will complement already existing major and trace element chemical suites and measurements of volatiles trapped in the volcanic glasses. By combining these new geochemical data with computer models of geodynamic processes, this research will allow the composition of mantle source material to be determined, as well as the physical condition under which melts are generated, transported, and aggregated under mid-ocean ridges. Broader impacts of this research are multifaceted and strong. They include tight integration of research and education, with undergraduates being involved in the full research process and being trained in state-of-the-art geochemical analytical work. Working with university programs that recruit minority scholars, the investigator will include minority students in his research group and train them in research thinking and high-end analytical work over the summer. Through the lead investigator and students involved in his laboratory, there will also be significant interaction with local elementary schools to help provide them with science programs and scientist role models to replace science educators who, due to budgetary constraints, have been cut from elementary school programs. Other broader impacts include support of an institution in an EPSCoR state (Rhode Island) and support of an NSF-funded analytical instrument which serves institutions across the state of Rhode Island.

大洋中脊与地球上数量最多的活火山和火山地貌有关。 了解海底岩浆喷发的形成方式以及它们来自什么深度和母岩成分/岩性，对于能够预测和模拟复杂的地壳过程至关重要。这项研究将完成一套重要的熔岩地球化学特征，从东太平洋隆起在中太平洋地区，通过生产的Sr，Nd，Pb和Hf同位素组成的80多个熔岩从Quebrada/发现/Gofar转换断层系统。同位素数据将补充现有的主要和微量元素化学套件以及对火山玻璃中挥发物的测量。通过将这些新的地球化学数据与地球动力学过程的计算机模型相结合，这项研究将能够确定地幔源物质的组成，以及洋中脊下熔融物产生、运输和聚集的物理条件。这项研究的广泛影响是多方面的和强大的。 它们包括研究和教育的紧密结合，本科生参与整个研究过程，并接受最先进的地球化学分析工作的培训。 与招收少数民族学者的大学项目合作，研究人员将在他的研究小组中包括少数民族学生，并在夏季对他们进行研究思维和高端分析工作的培训。通过首席研究员和参与他实验室的学生，还将与当地小学进行重要的互动，帮助他们提供科学课程和科学家榜样，以取代由于预算限制而被削减的科学教育工作者。其他更广泛的影响包括支持EPSCoR州（罗得岛）的一个机构，以及支持NSF资助的分析仪器，该仪器为罗得岛州的机构提供服务。