Deformation of the Earth: From Processes to Phenomena

该研究项目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。特别感兴趣的是构造区域在地震（地震）和地震（流动）变形之间循环的触发和机制。个别项目通常包括实地工作和实验室分析的结合，主要由研究生（本科生和研究生）承担，作为其学科训练的一部分。野外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，并辅以远程成像，如增强的无人机摄影测量和激光雷达（光探测和测距）。然后将数据整合到地质结构的三维模型中。分析技术范围从光学（光）显微镜和扫描电子显微镜（SEM）在厘米到微米（千分之一毫米）的尺度上表征纹理，以及用于粒度化学分析的电子显微探针（EMP）。后一种尺度的电子束扫描衍射（EBSD）不仅能够识别成分变化，还能够识别晶粒之间的晶体取向差异，这些差异用于推断变形“冻结”到岩石结构中的过程。这项研究的核心技术是透射电子显微镜（TEM）。透射电镜能够成像纳米级（百万分之一毫米）的矿物颗粒和颗粒，这是分析断层岩石的必要条件，断层岩石中的颗粒通常接近纳米级。由于纳米颗粒的表面积与体积之比比“正常”材料大得多，因此从标准观察结果简单地推断超细颗粒材料的过程（扩散、反应、颗粒变形）是不合适的。因此，透射电镜能够获取图像、晶体学数据和化学信息，以解决变形岩石内部的基本过程。通过微ct x射线分析实现三维孔隙度和纹理属性成像。***该研究项目涉及了解地球动力学，如地震、火山、由流体-岩石相互作用形成的经济矿床，这些相互作用集中在古老的断层和剪切带上。还有一种额外的间接影响，即国内保险业以及与外部灾害（如2010年海地地震）相关的外国援助和灾害援助造成的经济损失。对这类事件的反应要求对这类现象进行系统研究，以支持更好的预测模型。*****

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.*****