Deformation of the Earth: From Processes to Phenomena

地球变形：从过程到现象

• 批准号: RGPIN-2019-04423
• 负责人: White, Joseph
• 金额: $ 1.82万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=751193
• 关键词: Deformation; Earth; Processes; Phenomena

The research program seeks to understand processes by which rocks deform through consideration of natural examples, deformation experiments and theory. Particular interests are the triggers and mechanisms by which tectonic regions cycle between seismic (earthquakes) and aseismic (flow) deformation. Individual projects typically comprise combinations of fieldwork with laboratory analysis undertaken primarily by research students (undergraduate and graduate) as part of their disciplinary training. Field work includes classical geological mapping to determine the composition and geometry of distinct tectonic regimes, aided in turn by remote imaging such enhanced photogrammetry with drones, and LIDAR (light detection and ranging). Data are then integrated into 3-dimensional models of the geological structures. Analytical techniques range from optical (light) microscopy and scanning electron microscopy (SEM) to characterize textures at the scale of centimetres to micrometres (1 thousandth of a millimeter), and electron microprobe (EMP) for grain-scale chemical analysis. Electron beam scanning diffraction (EBSD) at the latter scales is capable of discerning not only compositional variations, but also crystallographic orientation differences among grains that are used to infer the progress of deformation "frozen" into the rock texture. A technique central to the research is transmission electron microscopy (TEM). TEM is capable of imaging mineral grains and particles to the nanometer scale (1 millionth of a millimeter), a necessary requirement for analyzing fault rocks in which particles often approximate this size. Because the ratio of surface area to volume for nanoparticles is so much greater than "normal" materials, it is not appropriate to simply extrapolate processes (diffusion, reactions, particle deformation) from standard observations to the ultra-fine-grained materials. Hence, TEM is able to acquire images, crystallographic data and chemical information at the scale needed to address the fundamental processes within deformed rocks. Imaging of 3-dimensional porosity and textural attributes is achieved by microCT x-ray analysis.    The research program relates to understanding dynamics of Earth seen as earthquakes, volcanoes, the formation of economic mineral deposits by fluid-rock interaction focussed along ancient faults and shear zones Although earthquake hazards are largely concentrated along the west coast of Canada, there is an additional indirect effect of hazard through financial losses by the domestic insurance industry and foreign aid and disaster assistance related to external disasters such as the 2010 Haiti earthquake. Reaction to such events argues for investment in systematic study of such phenomena in support of better predictive models.

该研究计划旨在通过考虑自然实例，变形实验和理论来了解岩石变形的过程。特别感兴趣的是触发器和机制，构造区域之间的地震（地震）和地震（流动）变形周期。个人项目通常包括实地考察与实验室分析的组合，主要由研究生（本科生和研究生）作为其学科培训的一部分。实地工作包括经典的地质测绘，以确定不同构造体系的组成和几何形状，反过来又通过远程成像（如无人机增强摄影测量）和激光雷达（光探测和测距）进行辅助。然后将数据整合到地质结构的三维模型中。分析技术包括光学显微镜和扫描电子显微镜（SEM），用于表征厘米至微米（千分之一毫米）尺度的纹理，以及用于颗粒尺度化学分析的电子微探针（EMP）。电子束扫描衍射（EBSD）在后者的规模是能够辨别不仅成分的变化，但也晶粒之间的结晶取向差异，用于推断变形的进展“冻结”到岩石纹理。这项研究的核心技术是透射电子显微镜（TEM）。TEM能够将矿物颗粒和粒子成像到纳米级（百万分之一毫米），这是分析断层岩的必要要求，其中颗粒通常接近该尺寸。由于纳米颗粒的表面积与体积之比“正常”材料大得多，因此不适合简单地从标准观察结果外推过程（扩散，反应，颗粒变形）到超细晶粒材料。因此，TEM能够在处理变形岩石内的基本过程所需的尺度上获取图像、晶体学数据和化学信息。三维孔隙度和纹理属性的成像通过microCT X射线分析实现。 该研究计划涉及了解地球的动力学，如地震，火山，通过流体-岩石相互作用形成的经济矿藏集中在沿着古老的断层和剪切带虽然地震灾害主要集中在沿着加拿大西海岸，还有一个额外的间接影响的危险，通过财政损失的国内保险业和外国援助和灾害援助有关的外部比如2010年海地地震。对这些事件的反应表明，需要投资于对这些现象的系统研究，以支持更好的预测模型。