Dike Growth and the Transition to Diapirism in Cracking, Flowing Rock

众所周知，深部的岩石可以以延性或脆性的方式变形，以响应更具流动性的物质(岩浆、水、盐等)的通过。从经验上看，赋存岩石和流动的流体之间的粘度差异越大，就越有可能在狭窄的裂缝和岩脉中找到流体，而在底辟和岩塞中找到流体的可能性就越小。尽管这一观察结果在直觉上很有吸引力，但迄今为止，几乎没有人努力量化宿主/流体粘度对比在确定可能或可能发生堤坝入侵的地质体制中的作用。PI将研究岩脉/底辟的转变，将岩脉作为粘弹性主岩中扩展的、充满流体的裂缝。这些结果除了具有普遍的地质学意义外，还应该特别应用于一些重要的问题和过程。这些问题包括花岗岩和蛇纹岩沿断层的浮力上升，花岗岩/地壳的粘性对比是否使得花岗岩可以通过断裂和流动的组合以高于斯托克流动溶液的速度上升(因此在冻结之前穿过更多的地壳)，以及在分叉(裂谷)的岩石圈块体之间浮力软流层上涌的问题。

It is well established that rock at depth can deform in either (or both) a ductile or brittle fashion in response to the passage of a more fluid material (magma, water, salt, etc.). Empirically, the greater the viscosity contrast between the host rock and the fluid moving around, the more likely one is to find the fluid in narrow cracks and dikes, and the less likely one is to find it in diapirs and plutions. Although this observation is intuitively appealing, as yet there has been little effort to quantify the role of host/fluid viscosity contrast in determining the geologic regimes under which dike intrusion is likely or possible. The PI will study the dike/diapir transition be treading dikes as propagating, fluid-filled cracks in viscoelastic host rock. The results, in addition to being of general geologic interest, should find particular application to a number of important questions and processes. These include the buoyant rise of granitic and serpentinite bodies along faults, the question of whether pluton/crustal viscosity contrasts are such that granities can ascend via a combination of fracture and flow, at rates greater than that of the Stoke's flow solution ( and hence traverse more of the crust before freezing), and the upwelling of buoyant asthenosphere between diverging (rifting) lithospheric blocks.