Kinetics of Melt-Rock Reaction in the Mantle

地幔熔岩反应动力学

• 批准号: 0510606
• 负责人: Yan Liang
• 金额: $ 27.34万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510606&HistoricalAwards=false
• 关键词: Kinetics; Melt; Rock; Reaction; Mantle

Melt-rock reaction is a fundamental and ubiquitous process that is associated with melt migration in the Earth mantle. It is responsible or partially responsible for the development of high porosity melt channels under the mid-ocean ridge, the development of dunite-harzburgite-lherzolite sequences in ophiolites, the diversity of magmas observed in island arc, and possibly the growth of continental crust through geological times. In this project, the PI will use kinetic and thermodynamic principles, mass transfer models, and laboratory experiments to better understand the kinetics of melt-rock reaction associated with melt migration in the mantle. The project will focus on three closely related themes: (1) experimental studies of the kinetics of melt-rock reaction in the mantle, (2) experimental and numerical studies of grain growth and grain size distribution during melt-rock reaction in the mantle, and (3) applications to geological field observations through computer simulations of melt-rock reaction in porous rocks and microanalysis of samples from Trinity and Josephine ophiolites. The laboratory part of the project involves reactive dissolution experiments and will be used to constrain the rate and mechanism of melt-rock reaction. Grain growth study will be used to constrain the permeability of part of the mantle that undergoes reactive dissolution. Reactive flow modeling using laboratory calibrated reaction rates and grain size data will be used to evaluate the petrologic and geochemical consequences of melt-rock reaction in the mantle and to explore the significance of concentration gradients across the dunite-harzburgite-lherzolite sequences in ophiolites. Results from this study will also provide valuable information for a diverse group of geologists, promoting cross-discipline integration in Earth Sciences. The proposed project will provide hands on experience for undergraduates, research opportunities for senior thesis, experimental and computational experience for graduate students.

熔体-岩石反应是地幔熔体迁移过程中一个普遍存在的基本过程。它是负责或部分负责的高孔隙度熔体通道的发展，大洋中脊下，在蛇绿岩的纯橄岩-方辉橄榄岩-二辉橄榄岩序列的发展，在岛弧中观察到的岩浆的多样性，并可能通过地质时代的大陆地壳的增长。在这个项目中，PI将使用动力学和热力学原理，传质模型和实验室实验，以更好地了解与地幔中熔体迁移相关的熔体-岩石反应的动力学。该项目将侧重于三个密切相关的主题：（1）地幔熔体-岩石反应动力学的实验研究;（2）地幔熔体-岩石反应过程中颗粒生长和粒度分布的实验和数值研究;（3）通过计算机模拟熔融物在地质现场观测中的应用，多孔岩石中的岩石反应以及对Trinity和Josephine Ophiglium的样品进行微观分析。该项目的实验室部分涉及反应溶解实验，并将用于限制熔体-岩石反应的速率和机制。颗粒生长研究将用于限制地幔的部分，经历反应溶解的渗透性。使用实验室校准的反应速率和粒度数据的反应流模型将被用来评估地幔中的熔体岩石反应的岩石学和地球化学后果，并探讨蛇绿岩中的纯橄榄岩-方辉橄榄岩-二辉橄榄岩序列的浓度梯度的意义。这项研究的结果也将为不同的地质学家群体提供有价值的信息，促进地球科学的跨学科整合。该项目将为本科生提供实践经验，为毕业论文提供研究机会，为研究生提供实验和计算经验。