俯冲带岩浆作用与大陆地壳生长

Magmatism in Subduction Zones and Growth of Continental Crust

大陆地壳的起源、生长和改造一直都是国际地学界广泛关注的热点问题,目前仍存在一定的争议,特别体现在陆壳增生的方式和速率上.为了探讨大陆地壳的生长方式,简要综述了俯冲带及其岩浆作用和大陆地壳生长的研究成果.俯冲带可划分为洋洋俯冲带、洋陆俯冲带和陆陆俯冲带,其岩浆作用以产出弧岩浆岩为主要特征,被广泛接受为大陆地壳生长的主要方式.目前主要有两种陆壳生长的假说:玄武岩模式和安山岩模式.玄武岩模式主要通过拆沉和底垫过程来实现新生地壳向大陆地壳的演化;安山岩模式则强调陆壳直接形成于产出安山质岩浆的俯冲带岩浆弧环境.俯冲带和碰撞带等板块汇聚边界是显生宙大陆地壳生长和改造的主要位置,俯冲带岩浆作用对陆壳生长发挥着重要的作用.

The origin,growth and reworking of continental crust have always been a hot topics in the international geosciences,and there are still some disputes,particularly about the mode and rate of continental crust growth.In order to discuss continental crustal growth style,it briefly reviews the research achievements of subduction-related magmatism and continental crustal growth.Subduction zones can be divided into oceanic-oceanic subduction zones,oceanic-continental subduction zones and continental-continental subduction zones,characterized by arc magmatic rocks.Subduction-related magmatism has been widely accepted as the main continental crustal growth style.At present,there are two hypotheses of the growth of continental crust:basalt model and andesite model.The basalt model mainly highlights the evolution of the new crust to the continental crust through the processes of delamination and relamination,while the andesite model emphasizes that the continental crust is directly formed in the magmatic arc environments of the subduction zones where andesitic magmas occur.Plate convergent boundaries such as subduction and collision zones are considered to be the main locations for the growth and reworking of the Phanerozoic continental crust,and subduction-related magmatism is of great significance to continental crustal growth.