海南岛早前寒武纪片麻岩的岩石化学特征和构造意义的初步研究  

A Preliminary Study on Petrochemistry Features and Structural Significances of Early Precambrian Gneisses in the Hainan Island

作　　者：吴根耀[1] 侯威[2] 

机构地区：[1]中国科学院地质与地球物理研究所,北京 [2]中国科学院办公厅,北京

出　　处：《地球科学前沿（汉斯）》2023年第5期592-600,共9页Advances in Geosciences

摘　　要：海南岛九所–陵水断裂以北地区出露的中元古代花岗岩里有早前寒武纪花岗–绿岩地体的残块。片麻岩是英云闪长质–奥长花岗质–花岗闪长质片麻岩(常称TTG岩套或灰色片麻岩)和花岗质片麻岩组合,以低铝片麻岩为特征。岩石化学特征与扬子克拉通的早前寒武纪片麻岩相似,说明海南克拉通在起源上与扬子克拉通有亲缘性。中生代时海南岛地区位于福建以南,因新生代亚洲东南大陆边缘的裂解而与福建分离并向西南漂移。海南岛现今的北东向构造是福建沿海燕山期北北东向构造的南延,因海南岛逆时针旋转了约160˚而形成。片麻岩呈北东向条带状延伸即受这一新生代构造控制。North of the Jiusuo-Lingshui Fracture, there outcrop some relict blocks of Early Precambrian grano-greenstone belt terrene floating in the Meso-Proterozoic granites. The gneisses are composed of trondhjemitic-tonalitic-granodioritic gneiss (the TTG suite or gray gneiss) and granitic gneiss. The petrochemical features indicate the Hainan Gneiss being the low-Al2O3 type, similar with the basement gneisses of the Yangtze Craton. It means the Hainan Craton, originally, having an affinity with the Yangtze Craton. During Mesozoic, the Hainan district would locate in south of Fujian. The Cenozoic rifting of Asian SE continental margin resulted in that the Hainan Island disjointed from Fujian and drifted southwestwards in the South China Sea. Meanwhile, the Hainan Island rotated about 160˚ anticlockwisely. The schist extends in a northeastward band, which is controlled by this Cenozoic tectonic movement.

关 键 词：片麻岩 岩石化学 低铝型 北东向构造 早前寒武纪 海南岛 

分 类 号：P61[天文地球—矿床学]