Co-operative research of granite mylonites in Japan

本文对日本花岗岩糜棱岩进行了描述，并对其形成过程和构造进行了讨论。花岗岩糜棱岩以岩浆弧形式发育于Hida带、Ryoke带、Abukuma-Kitakami带、Hidaka带和Greentuff带。它们是岩浆弧中的应变集中带。因此，弄清大型花岗糜棱岩带的形成过程和运动图像对认识岩浆弧构造具有重要意义。Komatsu（1992）和Hara（1992）对飞驒带的花岗糜伦岩带进行了研究，明确其发育分为两个阶段，即与中P/T型片岩隆升有关的Unazuki阶段和与Hunatsu花岗岩侵入有关的Hunatsu阶段。Ui和Yokoyama（1992）、Takagi（1992）、Hara（1992）、More和Takeshita（1992）对位于中构造线的良带的大型糜棱岩带进行了研究，明确了它是作为一个平坦剪切带发育的。分析了其在白垩纪花岗岩侵入期至日本海扩张期的运动图像。Koshiya（1992）和Hara（1992）对Abukuma-Kitakami带的大型糜伦岩带进行了研究，澄清了它们与Ryoke带不同，是垂直剪切带和水平剪切带，尽管这两个带的剪切带是同一代的。丰岛（1992）和丰岛与原（1990）对飞隆带的大型糜棱岩带进行了研究，明确了其在MORB型岩浆侵入期和钙碱性岩浆侵入期两个阶段发育为平卧剪切带，火成岩侵入剪切带进入直立状态，形成大糜棱岩带（飞隆西缘糜棱岩带）。绿化带糜棱岩带沿伊藤川—静冈构造线发育。小坂和泷泽（1992）、泷泽和小坂（1992）和岛本（1992）对其显微纹理和运动图像进行了分析。Masuda et al.（1992）、Takizawa and Kosaka（1992）、Hara et al.（1992）、Kang et al.（1992）、Koshiya（1992）和Simamoto（1992）对mylonites的微观结构、形成过程、运动图像和应力估计进行了讨论。少

In this co-operative research have been performed descriptions of granite mylonites in Japan and their formation processes and tectonics have been discussed. Granite mylonites are developed as large-scale zones in the Hida belt, Ryoke belt, Abukuma-Kitakami belt, Hidaka belt and Greentuff belt as magma-arcs. They are zones of strain concentration in magma-arcs. In order to understand tectonic of magma-arcs, therefore, it is very important to clarify formation processes and movement pictures of large-scale granite mylonite zones. Granite mylonite zone in the Hida belt has been studied by Komatsu (1992) and Hara (1992) clarifying that it was developed during two phases, Unazuki phase for tectonics related to the uplifting of medium P/T type schists and Hunatsu phase for tectonics related to the intrusion of Hunatsu granites. Large-scale mylonite zone in the Ryoke belt, which is placed along the Median Tectonic Line, has been studied by Ui and Yokoyama (1992), Takagi (1992), Hara (1992) a … More nd Takeshita (1992) clarifying that it was developed as a flat-lying shear zone. Its movement picture has bee analyzed during the period from the phase of Cretaceous granite intrusion to the phase of the Japan-sea spreading. Large-scale mylonite zones in the Abukuma-Kitakami belt have been studied by Koshiya (1992) and Hara (1992), clarifying that they were developed as upright shear zones with horizontal shear unlike the case of the Ryoke belt, though the shear zones in both belts are of the same generation. Large-scale mylonite zone in the Hidaka belt has been studied by Toyoshima (1992) and Toyoshima and Hara (1990), clarifying that it was developed as flat-lying shear zone during two phases, phase of intrusion of MORB type magma and phase of intrusion of calcalkaline magma, and then the shear zone with igneous intrusion was moved into upright attitude giving rise to great mylonite zone (Hidaka western margin mylonite zone). Mylonite zone in the greentuff belt is developed along the Itoigawa-Shizuoka tectonic line. Its microtextures and movement picture have been analyzed by Kosaka and Takizawa (1992), Takizawa and Kosaka (1992) and Shimamoto (1992). Microtextures, formation processes, movement pictures andstress estimation of mylonites have been discussed by Masuda et al. (1992), Takizawa and Kosaka (1992), Hara et al. (1992), Kang et al. (1992), Koshiya (l992) and Simamoto (1992). Less