中国变质核杂岩的基本特征

基于前人的研究基础之上 ,确立了中国变质核杂岩的三层结构 ,即盖层 (上部脆性变形层 )、滑脱层 (固态流变中间韧性层 )、核部 (变质核、同构造侵入岩 ) ,分析并总结了各层的主要特征。中国变质核杂岩的形成时间以燕山期为主 ,喜山期次之 ,还有晋宁期、加里东期、海西期以及印支期。依据中国变质核杂岩出露的大地构造位置 ,可分为板缘变质核杂岩和板内变质核杂岩两类 ,它们均与热异常和岩浆活动有密切的联系 ,变质核杂岩核部基本上都发生一期以上的岩体侵入 ,是找矿探矿的理想构造区。

REVIEW OF THE BASIC CHARACTERISTICS OF THE METAMORPHIC CORE COMPLEXS IN CHINA

Based on the predecessor's studies,a three-layer structure of the metamorphic core complex is established in this paper.The three layers include the cover (upside brittle distorted stratum), surge layer (the middle solid rheologic ductile layer) and the nucleus (metamorphic core and the paratectonic infracrustal rock).All the three-layer structure's major characters are summarized,and the forming time of the metamorphic core complex is marked out.The forming time is mostly Yanshan epoch,the second is Himalayan epoch, then Tsinning epoch,Caledonian epoch,Hercynian and Indosinian epoch.According to the metamorphic corecomplex's geotectonic locations,the author classifies the metamorphic core complex in China into two types.One is the plate edged metamorphic core complex and the other is the inner plate metamorphic core complex.All the metamorphic core complexs in China are related to anomalous thermality and magmatic activity.There are more than one time magmas invading in the nucleus of the metamorphic core complex.So metamorphic core complex is an ideal structure region for prospecting.