英云闪长岩-奥长花岗岩-花岗闪长岩(TTG)岩石构造组合及其亚类划分  

Discussion on the tonalite-trondhjemite-granodiorite (TTG) petrotectonic assemblage and its subtypes

作　　者：邓晋福[1] 刘翠[1] 狄永军[1] 冯艳芳[2] 肖庆辉[3] 刘勇[3] 丁孝忠[3] 孟贵祥[4] 黄凡[4] 赵国春[1] 吴宗絮[1] DENG Jinfu;LIU Cui;DI Yongjun;FENG Yanfang;XIAO Qinghui;LIU Yong;DING Xiaozhong;MENG Guixiang;HUANG Fan;ZHAO Guochun;WU Zongxu(School of Earth Sciences and Resources,China University of Geosciences (Beijing),Beijing100083,China;Development Research Center of China Geological Survey,Beijing 100037,China;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质调查局发展研究中心,北京100037 [3]中国地质科学院地质研究所,北京100037 [4]中国地质科学院矿产资源研究所,北京100037

出　　处：《地学前缘》2018年第6期42-50,共9页Earth Science Frontiers

基　　金：中国地质调查局地质调查项目(DD2016-0345,DD20160346,1212011220928,DD20160123(DD-16-049),121201004000150013([2018]第62号))

摘　　要：TTG岩石构造组合(或岩类)表征洋壳俯冲作用。本文提出TTG岩类的4个亚类:(1)镁安山岩系列(MA)低压型TTG亚类,形成于非常年轻和很热的洋壳俯冲,压力≤1 500-1 600 MPa,深度≤50-60 km,例如活动洋中脊俯冲的板片窗的边缘;(2)镁安山岩系列(MA)高压型TTG亚类,形成于比较年轻和较热的洋壳俯冲,压力≥1 500-1 600 MPa,深度≥50-60 km;(3)低镁(或非镁)安山岩系列(LMA)低压型TTG亚类,形成于洋内弧下地壳,压力≤1 500-1 600 MPa,深度≤50-60 km;(4)低镁(或非镁)安山岩系列(LMA)高压型TTG亚类,形成了大陆边缘弧山根带,压力≥1 500-1 600 MPa,深度≥50-60 km。对TTG岩类4个亚类的研究,并结合对无TTG形成的老的冷的俯冲带洋壳和冷的弧地壳以及幔楔有无岩浆产生等方面的研究,可以重建岩浆弧的壳幔结构和热结构,进而可为与洋俯冲有关的成矿作用提供地质背景。The TTG petrotectonic assemblage (or igneous series) characterizes subduction of oceanic crust.In this paper,we suggest four subtypes of the TTG series:(1)The magnesium andesite (MA) lower pressure subtype is formed at a subduction zone of very young oceanic crust at highest temperature,≤1500-1600 MPa pressure and≤50-60 km depth,for example,at the margins of the slab-window of the active mid-oceanic ridge subduction.(2)The magnesium andesite(MA)higher pressure subtype is formed at a subduction zone of relatively young oceanic crust at high temperature,≥1500-1600 MPa pressure and≥50-60 km depth.(3)The lower(or non)magnesium andesite (LMA) lower pressure subtype is formed at a lower crust of the intra-oceanic island arc at≤1500-1600 MPa pressure and ≤50-60 km depth.And (4) The lower (or non) magnesium andesite (LMA) higher pressure subtype is formed at the mountain root of the continental arc at≥1500-1600 MPa pressure and≥50-60 km depth.Using a combination of the four TTG assemblage subtypes and non-magma generation at the subduction zone of older oceanic crust at low temperature with or without magma generation at the mantle wedge,we may reconstruct the crust-mantle and thermal structures of the magmatic arcs and provide a geologic basis for oceanic subduction related mineralization.

关 键 词：英云闪长岩-奥长花岗岩-花岗闪长岩(TTG) 岩浆弧与洋俯冲 TTG岩系的亚类 镁安山岩和低(或非)镁安山岩 高压与低压 

分 类 号：P583[天文地球—岩石学] P588.1[天文地球—地质学]