Two-Phase Grain Damage and Geochemical Interactions: From Early Tectonic Evolution to Climate and Energy Transitions

两相颗粒损伤和地球化学相互作用：从早期构造演化到气候和能源转型

• 批准号: 1344538
• 负责人: David Bercovici
• 金额: $ 41.65万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1344538&HistoricalAwards=false
• 关键词: Two; Phase; Grain; Damage; Geochemical

The interaction between Earth's interior and surface occurs through complex processes and over widely varying time scales. On the geological time scale, plate tectonics and mantle overturn govern the long-term evolution of the surface, atmosphere and ocean. Conversely, on the human time scale, the rapid efflux of CO2 from burning fossil fuels is possibly best mitigated by returning it as rapidly to the mantle, through carbon sequestration in mafic and ultramafic rocks. However, carbon-sequestration is only one of many climate-change mitigation strategies, and low-emission fuels like natural gas, which bridge the decades-long transition from traditional fossil fuels to renewable energies, are important as well. These complex issues can be treated commonly with a field of material physics called damage theory, i.e., to treat weakening and focusing of tectonic plate boundaries as well as microcracking in near-surface fluid-bearing rocks. This project continues development of one such theory called two-phase grain-damage theory. This theory simply states the energy going into damage is deformational work that is stored as surface energy on micro-crack surfaces and/or the boundaries between mineral grains. In particular, plate-generation and early plate tectonic and surface evolution will be studied using grain-damage theory, since grain-reduction during deformation (as in field observations of rocks called mylonites) is likely important for generating weak plate boundaries. This project will seek to answer how grain-damage combines with other effects such as mantle melting and petrological changes at plate boundaries, which are important for understanding how plate tectonics originated in the ancient Archean Earth. Secondly, two-phase "micro-crack" damage with chemical reactions will be used to address mineral carbon sequestration in mantle derived (mafic and ultramafic) rocks, along with development of transitional energy such as shale-gas. Questions we seek to answer are how carbonation reaction affects damage (e.g., stress crack-corrosion), and how chemical reactions, grain growth and permeability evolution influence seismicity during fluid injection? The project involves a fundamental theory that contributes to many problems of geological and environmental fluid mechanics, rock mechanics, material science (e.g., metallurgy), climate-change and energy. Although the topics of plate tectonic evolution and energy transitions cover disparate geological and human time-scales, they are approachable with similar scientific advancements. Moreover, the long-term evolution of the Earth can inform us how to mitigate short-term imbalances. For example, reducing anthropogenic CO2, without pushing the problem onto future generations, requires a geologically long-term solution, and is therefore best addressed by mimicking the Earth's natural surface evolution and cycles.

地球内部和表面之间的相互作用是通过复杂的过程以及时间尺度变化的。在地质时间尺度上，板块构造和地幔倾覆了表面，大气和海洋的长期演变。相反，在人类的时间尺度上，通过在镁铁质和超镁铁质岩石中的碳固执，可以将二氧化碳从燃烧化石燃料产生的快速流出最佳地减轻。然而，碳序列只是许多气候变化策略之一，而诸如天然气之类的低排放燃料却弥合了从传统化石燃料到可再生能源的数十年过渡，也很重要。这些复杂的问题通常可以用称为损伤理论的物质物理领域来处理，即，以治疗构造板板边界的弱化和聚焦以及在近表面含水岩石中的微裂纹。该项目继续发展一种称为两相晶粒破坏理论的理论。该理论简单地表明，损伤的能量是变形工作，将其作为表面能量存储在微裂片表面和/或矿物晶粒之间的边界上。 特别是，将使用晶粒破坏理论研究板生成和早期板块构造和表面演化，因为变形过程中的晶粒还原（如在岩石的田间观测中）可能对产生弱板边界可能很重要。 该项目将寻求回答谷物损伤如何与其他效果相结合，例如板块边界的地幔熔化和岩石学变化，这对于理解板块构造如何起源于古代大帝地球很重要。 其次，使用化学反应的两相“微裂缝”损伤将用于解决地幔衍生（Mafic和Ultramafic）岩石中的矿物碳固存以及过渡能量（例如页岩气）的发展。我们寻求回答的问题是碳酸反应如何影响损害（例如，应力裂纹 - 腐蚀），以及化学反应，晶粒生长和渗透率的演化如何影响注入液体期间的地震性？该项目涉及一个基本理论，该理论助长了许多地质和环境力学，岩石力学，材料科学（例如冶金），气候变化和能量的问题。尽管板块构造进化和能量转变的主题涵盖了不同的地质和人类时间表，但它们具有相似的科学进步。此外，地球的长期演变可以告知我们如何减轻短期失衡。例如，减少人为CO2，而不将问题推向子孙后代，需要在地质上长期解决方案，因此可以通过模仿地球的自然表面演化和周期来最好地解决。