Collaborative Research: Serpentinization of oceanic crust: Integrated modeling of deformation, fracture, fluid flow, and heat transfer

合作研究：洋壳蛇纹石化：变形、断裂、流体流动和传热的综合建模

• 批准号: 1131471
• 负责人: Robert Lowell
• 金额: $ 18.28万
• 依托单位: Virginia Polytechnic Institute and State University
• 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 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1131471&HistoricalAwards=false
• 关键词: Collaborative; Research; Serpentinization; oceanic; crust

As the crust on and under the seafloor reacts with seawater, many of the minerals get altered from those without structural H2O to those with it. The most common of the latter minerals involved in seafloor alteration is serpentine. When this mineral forms, there is a large increase in the volume of the rock (up to a 40%). Due to the complex interplay of a variety of parameters such as temperature and temperature gradients, composition, water-rock ratio, mineral reaction, confining pressure, faulting, etc. our understanding of the impact of serpentinization on crack propagation in ocean crust, faulting, and other types of deformation both small and large, is limited. This research addresses this issue through an integrated approach that involves developing and applying theories for crack initiation and propagation in seafloor rocks and using the results to understand the formation of tectonic and structural features we see on and below the seafloor, features that tend to be associated with hydrothermal vent systems and seafloor faulting and deformation. Research will be carried out using mathematical models that have been revised to incorporate additional essential parameters and more precise equations to simulate crack initiation and propagation. Models will be modified to allow calculation of stresses and strains to determine the importance of large scale faulting and fracturing on internal and external serpentinized bodies. Results of the modeling will be checked against observational data from the Atlantis Massif, part of the Mid-Atlantic Ridge system and the Hyuganada Forearc region southwest of Japan. Broader impacts of the project include building infrastructure for science by producing models and modeling codes that have the potential to crossover into the fields of ore deposit and energy research. It also helps improve our ability to tap the potential of using mafic and ultramafic rocks on and below the seafloor as possible carbon sequestration sites for atmospheric carbon. Training of students, of which one is from a gender under-represented in the sciences, in computational geoscience is also involved, as is integration of research results into classroom training for undergraduate students.

当海底上下的地壳与海水发生反应时，许多矿物质会从不含结构水的矿物质变成含有结构水的矿物质。 参与海底蚀变的后一种矿物中最常见的是蛇纹石。 当这种矿物形成时，岩石的体积会大幅增加（高达 40%）。 由于温度和温度梯度、成分、水岩比、矿物反应、围压、断层等多种参数的复杂相互作用，我们对蛇纹石化对洋壳裂纹扩展、断层的影响的认识，而其他类型的变形无论大小，都是有限的。 这项研究通过一种综合方法解决了这个问题，该方法涉及开发和应用海底岩石中裂纹萌生和扩展的理论，并利用结果来了解我们在海底和海底看到的构造和结构特征的形成，这些特征往往是相关的。热液喷口系统和海底断层和变形。 研究将使用经过修改的数学模型进行，该模型已纳入额外的基本参数和更精确的方程来模拟裂纹的萌生和扩展。将修改模型以允许计算应力和应变，以确定内部和外部蛇纹石体上大规模断层和压裂的重要性。 建模结果将与来自亚特兰蒂斯地块（大西洋中脊系统的一部分）和日本西南部Hyuganada Forearc地区的观测数据进行检查。该项目更广泛的影响包括通过生成有可能交叉到矿床和能源研究领域的模型和建模代码来建设科学基础设施。 它还有助于提高我们挖掘利用海底上下的镁铁质和超镁铁质岩石作为大气碳可能的碳封存地点的潜力的能力。 还涉及计算地球科学方面的学生培训，其中包括对科学领域代表性不足的性别学生的培训，以及将研究成果纳入本科生课堂培训的内容。