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自从上新世以后的某个时间起,日本海的东缘就处于会聚的地质构造状态。缝合线位于日本Yamato海盆与Tohoku(东北)弧之间的海—陆边界上。沿着这条缝合线,可以观测到洋壳和壳下层的早期俯冲和仰冲,沿此缝合线有许多N-S走向的、以断层为边界的海岭和海槽。沿该带发生的几个M=6.9—7.7的压缩型地震的震源机制解与几个地质逆断层的观测结果一致。日本海地区的会聚应力,可能是由于印度-欧亚碰撞及其有关的东亚地区板块内或微板块之间的运动形成的。阿穆尔板块向东运动,引起沿该板块西缘的贝加尔扩张,以及沿其东缘的日本海会聚。
Some time since the Pliocene, the eastern edge of the Sea of Japan is in a converging geological formation. The suture is located on the sea-land boundary between Japan’s Yamato Basin and Tohoku (northeast) arc. Along this line of suture, early subduction and overthrust can be observed in the oceanic crust and in the subfacies beneath which there are many N-S strike-bound deltas and troughs. Focal mechanism solutions for several compression-type earthquakes with M = 6.9-7.7 that occurred along the belt are consistent with observations of several geological thrust faults. Convergence stresses in the Sea of Japan region may have been caused by the collision between India and Eurasia and their movements within or across the plate in East Asia. The movement of the Amur plate eastward caused the expansion of Baikal along the western margin of the plate and the convergence of the Japan Sea along its eastern margin.