Microstructural evolution in bitaxial crack‐seal veins: A phase‐field study
Microstructural evolution in bitaxial crack‐seal veins: A phase‐field study
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双轴裂缝封闭脉的微观结构演化：相场研究
DOI：
10.1002/2015jb011934
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
B. Nestler
中科院分区：
文献类型：
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作者：
K. Ankit;J. Urai;B. Nestler
通过外延晶体生长来封闭双轴裂纹是地壳中最常见的脉状形成过程，但这些过程中的微观结构过程的细节还没有被很好地了解。在这里，我们用相场方法在二维和三维上模拟了双轴裂隙封闭石英脉的演化。我们的数值模拟显示了不同的参数，如裂纹张开倾角、裂纹位置、晶粒度和取向等对织构演化的影响。我们研究了在石英外延生长过程中观察到的潜在的生长竞争。结果表明，与拉伸晶体等自然微结构有许多相似之处，并与先前的数值结果吻合较好。由于本研究选择的裂纹孔径与基质颗粒尺寸之比足够大，以便在完全封闭之前发生生长竞争，这将导致沿裂纹张开轨迹形成晶体碎片。我们解释了这种碎片痕迹如何作为裂缝密封静脉开放的潜在指示器，如果它们被证实在自然微结构中是常见的。最后，通过分析密封过程中二维和三维流体连通性的演变，强调了在数值模拟中考虑第三维的重要性。
Bitaxial crack sealing by epitaxial crystal growth is the most common vein‐forming process in Earth's crust, but the details of the microstructural processes in these are not well understood. Here we model the evolution of bitaxial crack‐seal quartz veins in two and three dimensions, using the phase‐field method. Our numerical simulations show the influence of different parameters, such as the obliquity of crack opening and crack location, grain size, and orientations on the evolving vein microstructure. We examine the underlying growth competition observed during epitaxial growth of quartz. Results show many similarities with natural microstructures such as stretched crystals and compare well with the previous numerical findings. As the ratio of crack aperture and matrix grain size for the present studies is chosen to be sufficiently large for growth competition to occur before complete sealing, it leads to the formation of crystal fragments along the crack‐opening trajectory. We explain how such fragment trails act as potential indicators of the opening of crack‐seal veins, if they are confirmed to be common in natural microstructures. Finally, we highlight the importance of accounting for the third dimension in the numerical simulations by analyzing the evolution of fluid connectivity in 2‐D and 3‐D during the sealing process.
DOI：
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发表时间：
2013
期刊：
The International Journal of High Performance Computing Applications
影响因子：
--
作者：
A. Vondrous;M. Selzer;J. Hötzer;B. Nestler
通讯作者：
B. Nestler