Crack geometries and deformation by the crack-seal mechanism in the Sambagawa metamorphic belt
Crack geometries and deformation by the crack-seal mechanism in the Sambagawa metamorphic belt
复制标题
三巴川变质带裂缝几何形状和裂缝封闭机制的变形
DOI：
10.1016/0040-1951(94)00238-5
复制
发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
E. Hara
中科院分区：
文献类型：
--
作者：
M. Toriumi;E. Hara
本文测量了桑巴川高压型变质带退变质作用中形成的石英封闭裂隙的几何形状。得到的裂纹宽度和长度之间的关系显示了幂律，具有幂指数范围从0.64到0.98的一个很宽的长度范围。裂纹的纵横比从0.008在云母区增加到0.03在黑云母区。填充石英的平均晶粒尺寸与裂纹宽度成正比，表明裂纹宽度由填充石英的生长速率决定。相邻裂纹间距的频率分布呈幂律关系。结合这些数据，推测裂缝封闭机制的变形受裂缝间距幂指数（分维）和填充石英的生长速率控制。由裂纹密封机制和位错蠕变制度的变形之间的边界划定为差应力，温度和裂纹分布图案的分形维数的函数。
Geometries of cracks sealed by quartz formed in the retrograde metamorphism of the Sambagawa high-pressure type metamorphic belt were measured. The relation obtained between width and length of cracks displays a power law having power exponents ranging from 0.64 to 0.98 for a wide range of lengths. The crack aspect ratios increase from 0.008 in the chlorite zone to 0.03 in the biotite zone. The average grain size of infilling quartz is proportional to the crack width, suggesting that the crack width is governed by the growth rate of infilling quartz. The frequency distribution of spacings of neighbouring cracks shows a power-law relation. Combining these data, deformation by the crack-seal mechanism is inferred to be controlled by the crack-spacing power index (fractal dimension) and growth rate of infilling quartz. The boundary between deformation by the crack-seal mechanism and the dislocation-creep regime is delineated as a function of differential stress, temperature and fractal dimension of the crack distribution pattern.