Petrogenesis of Hawaiian Tholeiites: Constraints from Non-Traditional Stable Isotopes

夏威夷拉斑玄武岩的岩石成因：非传统稳定同位素的制约

基本信息

批准号：
1524387
负责人：
Shichun Huang
金额：
$ 24.98万
依托单位：
University of Nevada Las Vegas
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1524387&HistoricalAwards=false
关键词：
Petrogenesis Hawaiian Tholeiites Constraints Non

项目摘要

This award will support an early career investigator to study the application of non-traditional stable isotopes, a novel tool, in the fields of high-temperature geochemistry and petrology. The ultimate goal of the project is to better understand the origin of Hawaiian volcanism. The proposed research involves educating and training graduate and undergraduate students in state-of-the-art analytical techniques and their applications to geosciences. The project will also help this early-career scientist build a state-of-the art laboratory that will support the research of a number of researchers and students not only at his own institution but also in other institutions allied to the Nevada System of Higher Education. The analytical geochemistry laboratory overseen by this investigator will serve a broad area of earth and environmental sciences, as well as to serve as regional infrastructure in an EPSCoR state. Finally, the proposed research will leverage previous NSF investments by using samples recovered from previous NSF funded programs, such as Hawaii Scientific Drilling Project.The Earth's mantle is thought to be composed of olivine-rich peridotite. However, the major element characteristics of some ocean island basalts (OIB), such as some Hawaiian lavas, cannot be produced by partial melting of peridotite. A variety of models have been suggested to explain the SiO2 variation in Hawaiian lavas, including melt-mantle reaction model, dacite magma model, and secondary pyroxenite model. On a global scale, Hawaiian lavas define the high-SiO2 endmember of the OIB compositional-isotopic spectrum. Consequently, understanding the origin of SiO2 variation within Hawaiian lavas is important in understanding the petrogenesis of global OIBs. Lavas from Mauna Kea, Koolau and Kahoolawe define two endmembers of the compositional-isotopic spectrum of Hawaiian lavas. The investigator proposes a detailed and systematic Mg and Fe isotopic study of Mauna Kea and Kahoolawe lavas to resolve this question. Koolau lavas have been extensively studied for Mg, Fe and Ca isotopic compositions. This effort expands on an ongoing study of the Ca isotopic compositions of these samples. It is suggested that non-traditional stable isotopic studies based on major elements such as Ca, Mg, and Fe may provide clues as to the nature of the compositional and isotopic variations shown in Hawaiian lavas. In the future, such approach can be applied to global OIBs to constrain their petrogenesis.

该奖项将支持早期职业研究者研究非传统稳定同位素（一种新工具）在高温地球化学和岩石学领域的应用。该项目的最终目标是更好地了解夏威夷火山的起源。拟议的研究涉及对研究生和本科生进行最先进的分析技术及其在地球科学中的应用的教育和培训。该项目还将帮助这位早期职业科学家建立一个最先进的实验室，不仅支持他自己所在机构的研究人员和学生的研究，还支持内华达州高等教育系统联盟的其他机构的研究人员和学生的研究。该调查员监督的分析地球化学实验室将服务于地球和环境科学的广泛领域，并作为 EPSCoR 州的区域基础设施。最后，拟议的研究将利用从以前的 NSF 资助项目（例如夏威夷科学钻探项目）中回收的样本来利用以前的 NSF 投资。地球的地幔被认为是由富含橄榄石的橄榄岩组成。然而，一些洋岛玄武岩（OIB）的主要元素特征，例如一些夏威夷熔岩，不能通过橄榄岩的部分熔融产生。人们提出了多种模型来解释夏威夷熔岩中 SiO2 的变化，包括熔体-地幔反应模型、英安岩岩浆模型和次生辉石岩模型。在全球范围内，夏威夷熔岩定义了 OIB 成分同位素谱的高 SiO2 端元。因此，了解夏威夷熔岩中 SiO2 变化的起源对于了解全球 OIB 的岩石成因非常重要。来自莫纳克亚山、库劳和卡胡拉维的熔岩定义了夏威夷熔岩成分同位素谱的两个端元。研究人员建议对莫纳克亚火山和卡胡拉维熔岩进行详细、系统的镁和铁同位素研究来解决这个问题。库劳熔岩的镁、铁和钙同位素组成已被广泛研究。这项工作扩展了正在进行的对这些样品的 Ca 同位素组成的研究。建议基于 Ca、Mg 和 Fe 等主要元素的非传统稳定同位素研究可以为夏威夷熔岩中显示的成分和同位素变化的性质提供线索。未来，这种方法可以应用于全球OIBs以限制其成岩作用。