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

当海底上和海底下的地壳与海水发生反应时，许多矿物质从没有水结构的变成了有水结构的。海底蚀变中最常见的后一种矿物是蛇纹石。当这种矿物形成时，岩石的体积会大大增加（高达40%）。由于温度和温度梯度、成分、水岩比、矿物反应、围压、断裂等多种参数的复杂相互作用，我们对海洋地壳蛇纹岩化对裂缝扩展、断裂和其他大小变形类型的影响的认识有限。本研究通过一种综合的方法解决了这个问题，包括开发和应用海底岩石中裂缝起裂和扩展的理论，并利用结果来理解我们在海底和海底下方看到的构造和结构特征的形成，这些特征往往与热液喷口系统和海底断裂和变形有关。研究将使用经过修订的数学模型来进行，以纳入额外的基本参数和更精确的方程来模拟裂纹的起裂和扩展。模型将被修改，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裂和破裂的重要性。模拟的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前弧地区的观测数据进行核对。该项目的更广泛影响包括通过生成模型和建模代码为科学建设基础设施，这些模型和代码有可能跨入矿床和能源研究领域。它还有助于提高我们利用海底和海底下的基性和超基性岩石作为大气碳的潜在固碳点的潜力。对学生（其中一名来自科学领域中性别代表性不足的学生）进行计算地球科学方面的培训，并将研究成果纳入本科生的课堂培训。

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.