Fracture Mechanics and Tectonics of Magma Transport Through the Lithosphere

[9219824] Rubin野外观察表明，在岩壁扩展的尖端产生的非弹性变形区可能比实验室岩石破裂实验中在裂缝尖端产生的非弹性变形区大得多。这与“断裂韧性”是一种独立于尺度和载荷配置的岩石属性的概念直接冲突。即使在较浅的深度，地球上的岩石破裂也会在足够高的围压下发生，而工程破裂力学的标准概念并不适用。这些结果主要应用于解释由堤坝产生的非弹性变形的露头尺度观测及其地质意义。这项工作将把这种分析和方法扩展到更大尺度的变形，特别是解释与火山地区岩浆运输有关的地震。＊＊＊

9219824 Rubin Field observations indicate that zones of inelastic deformation produced at the tips of propagating dikes can be much larger than those produced at crack tips in laboratory rock fracture experiments. This is in direct conflict with the concept that "fracture toughness" is a rock property, independent of scale and loading configuration. Even at shallow depths, rock fracture in the Earth takes place at sufficiently high confining pressure that standard concepts of engineering fracture mechanics do not apply. These results have been applied primarily to interpreting outcrop-scale observations of inelastic deformation produced by dikes and their geologic implications. This work will extend this analysis and approach to larger scales of deformation, and in particular to the interpretation of earthquakes associated with magma transport in volcanic regions. ***