华南花岗岩研究的回顾与展望

The Study of Granitic Rocks in South China: Looking Back and Forward

半个世纪以来 ,华南花岗岩研究经历了 3个发展阶段 :第一阶段 ,重点研究了花岗岩的时空分布。根据地质证据与同位素年龄数据 ,证实华南存在多旋回的花岗岩 ,即晚元古代花岗岩、加里东期花岗岩、海西 -印支期花岗岩和燕山期花岗岩。基本规律是 :不同的造山旋回伴有相应的花岗岩。大体上 ,自西北往东南 (向洋方向 )花岗岩时代呈愈来愈新的趋势 ;第二阶段 ,重点研究了花岗岩的成岩物质来源 ,划分为M型、I型、S型和A型 ,研究不同成因类型花岗岩形成的构造环境及其岩石地球化学标志 ;第三阶段 ,着重研究壳幔作用与花岗岩成因 ,例如研究玄武岩浆底侵作用与花岗岩的成因联系 ,以及岩浆混合作用与花岗岩成分多样性的原因。此阶段研究方兴未艾 ,仍在深入开展之中。今后主要研究方向 ,环绕 3个问题进行 :(一 )壳幔作用与A型花岗岩成因 ;(二 )陆内花岗岩浆产生的方式和原因 (变质核杂岩、花岗岩穹窿、复式花岗岩体 ) ;(三 )华南大花岗岩省成因。

The past half a century has witnessed three stages in the study of granitic rocks in South (China). Stage 1 began in the 1960s, focusing on the temporal and spatial distribution of granitic rocks. Based on geological evidence and isotopic dating, it was verified that there exist polycyclic granitic rocks in South China, including late Proterozoic, Caledonian, Hercynian-Indosinian and Yanshanian granitoids. It was recognized that different orogenic cycles were accompanied by corresponding granitic rocks. Generally, the age of granitic rocks tends to be younger and younger from northwest to southeast (towards the ocean side). Stage 2 was from the 1970s to the 1980s, concentrating on the petrogenic material sources of granitic rocks. Granitic rocks were classified into four types (types M, I, S and A) in terms of the mechanisms of their formation. During this period researchers also studied the tectonic environments in which various genetic types of granitic rocks were formed, as well as their petro-geochemical criteria. Stage 3 began in the 1990s and is still making progress. The research in this stage has been focusing on the relationships between crust-mantle interaction and the formation of granitic rocks, such as that between the underplating of basaltic magma and the genesis of granitic rocks, and that between magma mingling and the variation of granitic composition. The future research in this field should focus mainly on the following three topics: 1. the relationships between crust-mantle interaction and the genesis of A- type granitoids; 2. the mechanisms of formation of intracontinental granitic magma (metamorphic core complexes, granitic domes, and composite granitic plutons); and 3. the genesis of the great granitic provinces in South China.