安庆——贵池矿集区及邻区深部电性结构研究  

The deep electrical structure across Anqing-Guichi ore concentration area

作　　者：王刚[1] 方慧[1] 仇根根[1] 黄继民[2] WANG Gang;FANG Hui;QIU Gengen;HUANG Jimin(Institute of Geophysical and Geochemical Exploration, CAGS, Langfang 065000, Hebei, China;No.3 Gold Geological Party,CAPF, Harbin 150006, Heilongjiang, China)

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [2]武警黄金第三支队,黑龙江哈尔滨150006

出　　处：《中国地质》2019年第4期795-806,共12页Geology in China

基　　金：国家自然科学基金项目“江南造山带东段岩石圈三维电性结构研究”（41574068）;国家重点研发计划项目“华南北段地壳三维电性结构探测研究”（2016YFC0600201）;中国地质调查局地质调查项目“钦杭结合带及邻区深部地质调查”（121201108000160913,DD201682,DD20190012）“武夷山成矿带区域大地电磁测深”（12120114005801）;中国地质科学院基本科研业务费项目“江南造山带东段岩石圈结构的地震学成像研究”(AS2017J05)联合资助~~

摘　　要：长江中下游地区经历了多期次的地质构造演化具有丰富的矿产资源,对重要矿集区及其邻区的深部电性结构进行研究具有重要意义。通过对穿过安庆-贵池矿集区的一条宽频带大地电磁测深长剖面数据进行分频段以及分区反演,构建了覆盖大别造山带至下扬子地块东缘的二维电性结构模型。发现矿集区的深部电性结构与邻区的构造单元具有显著差异,大别造山带和江南隆起带与浙赣凹陷之间的地壳整体表现为高阻特征,而下扬子坳陷和江南隆起带之间存在岩石圈上地幔尺度的高导电异常体并且与地壳浅部的高导体相连。安庆-贵池矿集区的成矿机制主要为燕山期陆内俯冲以及早白垩时期的伸展作用,矿集区下地壳加厚、拆沉和上地壳丰富的断裂系统起到了重要的控矿作用。The middle and lower reaches of the Yangtze River have experienced multiple stages of geological evolution and are rich in mineral resources. In this paper, a two-dimensional electrical structure model covering the Dabie orogenic belt and the Lower Yangtze block was constructed by inverting a long magnetotelluric profile passing through the Anqing-Guichi ore concentration area by sub-band and sub-segment inversion scheme. According to the obtained electrical structure, the lithospheric structure beneath the ore concentration area is significantly different from that of the adjacent areas. Both the crusts under Dabie orogenic belt and between Jiangnan uplift belt and Zhegan depression are characterized by high resistivity, while the lithospheric upper mantle between Lower Yangtze depression and Jiangnan uplift belt is electrically conductive with a deep conductor extending upward to the conductors in the upper crust. The metallogenic mechanism of Anqing-Guichi ore concentration area was mainly the Yanshanian intra-continental subduction and the early Cretaceous extension deformation. The thickening and sinking of the lower crust and the abundant fault system in the upper crust underneath the ore concentration area may have played an important role in mineralization.

关 键 词：长江中下游成矿带 安庆-贵池矿集区 大地电磁测深 壳幔电性结构 

分 类 号：P631.3[天文地球—地质矿产勘探]