俯冲带是壳幔物质交换的关键环节,也是大陆地壳生长的重要场所。虽然对俯冲带的板块动力学机制、岛弧和弧后盆地演化开展了大量的研究,然而人们对于俯冲作用究竟是如何开始的却一直不太清楚。可能的机制包括“诱发说”和“自发说”两种假说。诱发说提出俯冲带的形成主要通过俯冲板块的拖拽(slab-pull)和洋脊的推挤作用(ridge-push)等外力的作用实现的,而自发说则强调较老的岩石圈板块沿岩石圈薄弱带(邻近年轻和较轻岩石圈的转换断层)的沉降作用 Subduction zone is the key link of material exchange between crust and mantle and also an important site for the growth of continental crust. Although a great deal of research has been carried out on the plate dynamics of subduction zones, the evolution of island arcs and backarc basins, it remains unclear exactly how subduction began. Possible mechanisms include the two “hypothesis” and “spontaneous said.” Induction suggests that the formation of subduction zones is achieved mainly by external forces such as slab-pull on the subducting segments and ridge-push on the ocean ridge, whereas the spontaneous argument emphasizes that the older lithospheric plate rocks along the rock Settlement of the zone weak zone (transition fault adjacent to young and lighter lithosphere)