What happens to deformed rocks after deformation? A refined model for recovery based on numerical simulations
What happens to deformed rocks after deformation? A refined model for recovery based on numerical simulations
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DOI：
10.1144/sp394.11
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发表时间：
2013-12
期刊：
影响因子：
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通讯作者：
V. Borthwick;S. Piazolo;L. Evans;A. Griera;P. Bons
中科院分区：
文献类型：
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作者：
V. Borthwick;S. Piazolo;L. Evans;A. Griera;P. Bons
在中地壳的大部分地区，变形导致应变岩石由具有可变位错密度的晶粒和以逐渐变形和亚晶粒结构为特征的显微结构组成。这些岩石在高温下的变形后驻留通过静态恢复和重结晶导致微观结构调整。在这里，我们采用数值技术来模拟在温度或低于变形温度的晶内恢复。该模拟是基于存储的能量最小化，通过物理材料点相对于其直接环境的局部旋转与定向误差有关。系统地改变三个温度和/或变形几何形状相关参数：（1）变形诱导位错类型，（2）位错迁移率和（3）位错相互作用体积的大小。与先前发表的原位实验的比较表明，数值和实验结果的一致性。他们显示温度和位错类型依赖的小尺度波动在亚晶界的取向差和亚晶粒内的取向变化。这可以解释为位错相互作用体积的增加和攀移激活的综合效应。我们的工作表明，即使变形后的温度等于或低于变形温度，微观结构也会发生显着变化：这与大多数变形岩石相关。
Abstract Deformation, in large parts of the middle crust, results in strained rocks consisting of grains with variable dislocation densities and microstructures which are characterized by gradual distortion and subgrain structures. Post-deformation residence of these rocks at elevated temperatures results in microstructural adjustments through static recovery and recrystallization. Here, we employ a numerical technique to simulate intragrain recovery at temperatures at or below the deformation temperature. The simulation is based on minimization of the stored energy, related to misorientation through local rotation of physical material points relative to their immediate environment. Three temperature- and/or deformation-geometry-dependent parameters were systematically varied: (1) deformation-induced dislocation types, (2) dislocation mobility and (3) size of dislocation interaction volume. Comparison with previously published in situ experiments shows consistency of numerical and experimental results. They show temperature- and dislocation-type-dependent small-scale fluctuations in subgrain-boundary misorientations and orientation variation within subgrains. These can be explained by the combined effect of increase in dislocation interaction volume and activation of climb. Our work shows microstructure can be significantly modified even if the post-deformational temperature is at or below the deformation temperature: a scenario relevant for most deformed rocks.