大兴安岭中南段构造岩浆岩带深部地质成矿作用  

Deep mineralization processes in the central—south Great Hinggan magmatic belt

作　　者：苏美霞 杨波[3] 吴艳君 颜萍 孟晓玲[1,2] SU Meixia;YANG Bo;WU Yanjun;YAN Ping;MENG Xiaoling(Geological Survey of Inner Mongolia,Hohhot,010020;Inner Mongolia Institute of Land and Resources Exploration and Development,Hohhot,010020;School of Earth Sciences,Zhejiang University,Hangzhou,310027)

机构地区：[1]内蒙古自治区岩浆活动与找矿重点实验室,呼和浩特010020 [2]内蒙古自治区地质调查院,呼和浩特010020 [3]浙江大学地球科学学院,杭州310027

出　　处：《地质论评》2020年第5期1321-1333,共13页Geological Review

基　　金：内蒙古自治区地质勘查基金管理中心院士项目“内蒙古北山—西拉木伦构造带深部构造与成矿预测研究”(编号:2017-YS02)的成果。

摘　　要：大兴安岭中南段位于索伦—西拉木伦断裂带与嫩江—白城断裂带交汇域,区内大规模岩浆活动、成矿作用与深部地质活动密切相关。深部地球物理研究成果显示:该区域上地幔存在埋藏较浅的低速、低阻、高热异常体,推断应是深部软流体局部上涌的显示;下地壳存在低密度、低速、高导层,推断是因软流体上涌,诱发下地壳重熔,形成所谓下地壳热流体引起。总之该区域软流层厚度大,热活动性强是引起大规模的岩浆活动及多金属矿床集中分布的深部地质因素。而古生代古亚洲洋洋壳俯冲消减,华北板块、西伯利亚板块陆—陆碰撞拼接及至中生代晚期太平洋板块俯冲作用是引起软流层上涌、下地壳重熔等强烈的壳幔相互作用之源动力。The central—south Great Hinggan Magmatic Belt is located in the intersection of Solon—Xar Moron River fault and Nenjiang—Baicheng fault.Large-scale magma activities and mineralization are closely related to deep geological processes in this region.The results from integrated geophysical surveys show that low-velocity,low-resistivity,hot anomalies probably exist in the lower-crust and upper mantle depth in this area.We propose that this low density,low-velocity and high-conductivity layer in the lower crust depth might be the hot fluid caused by mantle upwelling,then it melted the lower crust from heating.Generally,the thick asthenosphere and active thermal events in this region are the key factors which caused the large-scale magmatism and mineralization.We suggest that the strong interactions of the crust and mantle in this region,e.g.the upwelling from asthenosphere and the remelt of lower crust,may cause by the subduction of Paleo-Asian Ocean slab,the collision and collage between the North China craton and the Siberian craton,and the subduction of Pacific Plate starting from Late Mesozoic.

关 键 词：大兴安岭中南段 软流体 深部地质作用 

分 类 号：P611[天文地球—矿床学]