Flow of rocks

随着板块之间的缓慢移动，地壳处于一种流动的状态。虽然它们每年只移动几厘米，但随着地质时间的推移，这会累积起来。例如，1厘米/年相当于100-1000年的1000公里。这是两块板块碰撞形成山链的合理时间跨度。为了让板块移动，它的底座和边缘必须变形。地表附近的运动由破裂(断层作用)来调节，这可能会导致地震。在深处，由于压力，它被韧性流动所容纳；结晶岩石作为固体流动，没有破裂。岩石越热，它流动的速度就越快。竖立在阳光下的蜡烛弯曲是一个延展的过程。冰川的行为类似于岩石，它们在深处像固体一样缓慢流动，并在地表附近形成断层(裂缝)。此外，在温暖的加拿大南部，它们的流动比在寒冷的南极洲要快得多。我对所有尺度的变形机制感兴趣，从板块到微观。其机制受岩石性质、温度、围压、变形速率和边界条件(例如板块碰撞或移动)等因素的影响。这些因素决定了变形岩石的特征，并通过对这些特征的考察，重建了变形历史。例如，板岩的裂隙是变形历史的产物；在较高温度下类似的历史产生片岩。我感兴趣的是解开选定地区(目前在加拿大科迪勒拉)的变形历史，以了解其一般过程和基本原理。我的工作方法包括实地观察、理论考虑、数值和物理实验、确定过去的温度和压力，以及确定历史上不同阶段的年代。这类工作是理解板块构造和相关现象的基础。

The earth's crust is in a state of flux as the plates slowly move relative to one another.  They only move centimetres per year, but over geological time this adds up. For example, 1 cm/year is equivalent to 1,000 km in 100,000,000 years. This is a reasonable time-span for the development of a mountain chain by the collision of two plates. For a plate to move, its base and edges have to deform. Movement near the surface is accommodated by fracturing (faulting), which may result in earthquakes. At depth, due to pressure, it is accommodated  by ductile flow; the crystalline rock flows as a solid, without fracturing. The hotter the rock the faster it flows. The bending of a candle standing in the sun is a ductile process. The behaviour of glaciers is similar to that of rocks, they flow slowly as a solid at depth, and form faults (crevasses) near the surface. Also, their flow is considerably faster in warm southern Canada than in frigid Antarctica. I am interested in the mechanisms responsible for deformation at all scales, from plate to microscopic. The mechanisms are influenced by such factors as: rock properties, temperature, confining pressure, rate of deformation and boundary conditions (e.g. plates colliding, or moving apart). These factors determine the characteristics of the deformed rock, and by examining the characteristics, I reconstruct the deformation history. For example the fissility of slate is a product of the deformation history; a similar history at higher temperature produces a schist. My interest is in unraveling the deformation history of selected areas (currently in the Canadian Cordillera), in order to understand the general processes and  basic principles. My modus operandi involves field observation, theoretical considerations, numerical and physical experimentation, determination of past temperature and pressure, and dating of the various stages in the history. Work of this type is fundamental to understanding plate tectonics and related phenomena.