Prograde clay minerals reactions along a frontal thrust branching from a decollement in an ancient accretionary prism
Prograde clay minerals reactions along a frontal thrust branching from a decollement in an ancient accretionary prism
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沿着从古代增生棱柱中的滑脱分支分支的锋面推力进行的粘土矿物反应
DOI：
10.1016/j.tecto.2013.04.024
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发表时间：
2013
期刊：
影响因子：
2.9
通讯作者：
Kimura. G
中科院分区：
文献类型：
--
作者：
Kameda;J.;Yamamoto;Y.;Hamada;Y.;Kimura. G
在日本中部三浦岛和博索半岛的南部，发现了从古老的吸积棱柱(Miura-Boso吸积棱柱)的解体分支而来的叠瓦状冲断化石。通过对叠瓦式逆冲断裂之一的Shirako断裂沿线断层岩石的粘土矿物学分析，揭示了伊利-蒙皂石混层(I-S)的局部伊利石化和高岭石的部分破裂。X-射线衍射谱中I(001)-S(001)反射的形状表明，断层泥中的I-S微晶中的伊利石含量比围岩中的伊利石含量高约9%。这些结果表明，由于高速滑动引起的摩擦加热，在滑移带内存在局部温度异常。热模型结合I-S的伊利石化动力学模拟表明，该反应可能是由峰值温度为~450°C的多次高速滑移促进的，这表明地震破裂反复传播到棱柱脚趾，这也是从现代吸积棱柱(在南开海槽)中推断的。
Fossil imbricate thrusts, branching from a décollement in an ancient accretionary prism (the Miura–Boso accretionary prism), are exposed in the southern parts of the Miura and Boso peninsulas in central Japan. An analysis of the clay mineralogy of fault rocks along one of the imbricate thrust faults, the Shirako Fault, revealed local illitization of mixed-layer illite–smectite (I–S) and the partial breakdown of kaolinite. The shape of the I(001)–S(001) reflection in the X-ray diffraction pattern suggests that the illite fraction in I–S crystallites within the fault gouge is ~9% more than in the surrounding rocks. These results imply that there has been a local temperature anomaly within the slip zone, attributable to frictional heating induced by high-velocity slip. A thermal model, coupled with a kinetic simulation of illitization in I–S, suggests that the reaction was probably facilitated by multiple high-velocity slips at a peak temperature of ~450°C, suggesting repeated seismic rupture propagations to the prism toe, as also inferred from the modern accretionary prism (in the Nankai Trough).