安第斯型大陆边缘的A型孪生花岗岩带—以福建沿海为例

本文中同熔和改造系列是以岩石形成的不同方式、条件和过程为基础而作出的花岗岩成因分类。以此为前提,我们发现同时代两个系列花岗岩带常常平行成对分布,与相应时期的B型或大陆内部挤压俯冲带构成有规律的平行分布序列,据此,我们提出了孪生花岗岩带的概念,并指出有A型、AB型和B型三种孪生分带型式。本文以福建沿海(晚)燕山期孪生花岗岩带为例,系统阐述了产于活动大陆边缘的A型孪生花岗岩带的特征、成因及其形成的板块构造模式,将花岗岩成因与板块构造的关系从地球的化学分异原理、规律和动力上联系起来。

A-TYPE TWIN GRANITE BELTS OF THE ANDEAN-TYPE CONTINENTAL MARGIN-WITH FUJIAN COASTAL AREA AS AN EXAMPLE

Syntexis-and transformation-series granitoids have been redefined by the present authors only according to their different petrogenic styles, conditions and processes.Our recent studies on distributions of the two series of granitoids and their relations to plate tectonics revealed a worldwide regularity that a syntexis-series and a transformation-series granite belts of the same geological time are commonly paired and both of them run parallel to the contemporary B-type or intracontinental compression-subduction zone. It is named twin granite belts and can be divided into 3 types respectively called A-, AB-and B-type twin granite belts. With the Fujian coastal area as an example, this paper elucidates systematically the characteristics and the genesis of A-type twin granite belts developed in Andean-type continental margin area, and proposes a petrogentic model for the twin belts involving oceanic plate subduction which connects granite genesis with plate movements in accordance with the rules and dynamics of the earth material differentiation.