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在板块构造格架中,海沟—岛弧—弧后体系中发生的基本机制据信是大洋岩石圈的俯冲作用。然而,这种模式多少是作为海底扩张的必然结果而发展起来的。现在的问题是这种俯冲模式能否解释海沟—岛弧—弧后体系的全部主要特征。很多特征是容易解释的,例如逆断型板内地震及和田—贝尼奥夫带上的深震。但要解释弧后区广泛扩张和高热流的发生,以及弧系的火山活动则是十分困难的。解决这类问题的途径或许可在所谓的“比较俯冲学”里找到,所谓“比较俯冲学”,即存在两种基本的俯冲方式:一种是智利型的,其在岛弧和弧后区造成挤压应力体制;另一种是马里亚纳型的,其造成的是引张应力体制。本文根据这两种俯冲方式,对全球俯冲带进行了分类,并讨论了这两种俯冲方式的构造含意和成因。
In the tectonic framework of the block, the underlying mechanism occurring in the trench-island arc-backarc system is believed to be the subduction of the oceanic lithosphere. However, how much of this model has been developed as a corollary of the expansion of the seabed. The question now is whether this subduction mode can explain all the main features of a trench-island arc-backarc system. Many features are easy to interpret, such as an intraseasonal intraplate earthquake and a deep shock on the Wada-Benioff belt. However, it is difficult to explain the widespread expansion of the backarc area and the occurrence of high heat flux, as well as the volcanic activity of the arc system. The solution to such problems may be found in the so-called “comparative subduction science”. The so-called “comparative subduction science” means that there are basically two subduction ways: one is of the Chilean type, Resulting in squeezing the stress system; the other is the Mariana type, which is caused by the tensile stress system. Based on these two subduction methods, this paper classifies the global subduction zones and discusses the tectonic implications and causes of the two subduction modes.