滁州褶冲亚带深部地质特征的综合物探解译:对铜金矿床找矿的启示  

Deep Geological Features of Chuzhou Fold-trust Sub-belt and the Enlightenment to the Prospecting of Copper-gold Deposits:Inference from Comprehensive Magnetic-Gravity-AMT

作　　者：张嵩松 杨晓勇[1] 王光杰[3] 赵文广[2] 王金鑫 张志 ZHANG Songsong;YANG Xiaoyong;WANG Guangjie;ZHAO Wenguang;WANG Jinxin;ZHANG Zhi(School of Earth and Space Sciences,China University of Science and Technology,Hefei 230001,Anhui,China;Geological Survey of Anhui Province,Hefei 230001,Anhui,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Geological Exploration Technology Institute of Anhui Province,Hefei 230001,Anhui,China;No.327 Team of Bureau of Geology and Mineral Exploration of Anhui Province,Hefei 230001,Anhui,China)

机构地区：[1]中国科学技术大学地球和空间科学学院,安徽合肥230001 [2]安徽省地质调查院,安徽合肥230001 [3]中国科学院地质与地球物理研究所,北京100029 [4]安徽省勘查技术院,安徽合肥230001 [5]安徽省地质矿产勘查局327地质队,安徽合肥230001

出　　处：《大地构造与成矿学》2022年第4期710-727,共18页Geotectonica et Metallogenia

基　　金：国家重点研发计划项目(2016YFC0600404);国家自然科学基金项目(41673040);安徽省公益性地质项目(2014-g-6);安徽省重点研究与开发计划项目(2022I07020010)联合资助。

摘　　要：滁州褶冲亚带是位于长江中下游地区重要的铜金成矿区带,以西侧黄破断裂与东侧滁河断裂为边界,深入了解本区的深部地质特征对于该区隐伏铜金矿床的矿产勘查工作具有重要意义。本文结合实测地质剖面,通过解译三条与本区主要构造方向垂直的重力、磁法和音频大地电磁测深(AMT)综合剖面,提取深部构造信息并进行解译。地质体深部解译主要依据电阻率的变化、ΔT化极磁异常、布格重力异常的曲线特征和实测剖面进行综合推断,获得以下结论和认识:①黄破断裂两侧存在较大规模的隐伏断层,在不同地区主断面的深部形态和逆冲推覆距离不同;②滁河主断裂倾向北西,倾角60°~70°,形态较为稳定,在苏家湾-夏阁地区除主断裂外,南东侧还发育较大规模的反冲断层;③区域内隐伏岩体顶界隐伏深度普遍在0.5~1.5 km之间,其围岩主要为震旦系和寒武系的碳酸盐岩;④黄破断裂主断面西侧震旦纪地层内次级断裂较多,地层产状变化较大;南东侧深部的相对低阻特征指示深部的褶皱变形更加强烈。总体来说,重力、磁法和AMT综合剖面对该区深部构造形态具有良好的探测效果,结合区域成矿模型,推断隐伏岩体与碳酸盐岩地层的接触带部位是矽卡岩型铜金矿床的有利成矿部位,推荐以高精度重磁方法为主继续开展找矿工作;隐伏断裂形成的构造破碎带以及其与褶皱构造相交的部位是微细浸染型金矿的有利成矿位置,建议先明确隐伏次级断裂的空间位置以间接找矿。The Chuzhou fold thrust sub-belt is an important Cu-Au metallogenic zone in the Middle-Lower Yangtze Metallogenic Belt,which is bounded by the Huangpo fault in the west and the Chuhe fault in the east.A thorough understanding of the geological characteristics of this area will shed light on the exploration of concealed Cu-Au deposits.Combined with the geological background,the deep geological structures were inferred through interpretation of three gravity-magnetic-AMT composite profiles perpendicular to the mainly NE trend structures in this area.The deep geological bodies are interpreted mainly on the basis of the changes of resistivity,characteristics of reduction-to-the-pole of magnetic anomalies and bouguer gravity anomalies,as well as the features of outcrops.Macroscopically,the Huangpo fault has a relatively long nappe distance and dip angles varying from 70°,to 30°and then to 70°from shallow to deep.Interestingly,a large concealed fault is detected about 8 km to the east the main fault,which is NW inclining with a dipping angle of 50°-60°.In the Sujiawan-Xiage area,however,the Huangpo fault dips 40°-70°from shallow to deep,with a relatively short nappe distance.On its west side,a large concealed fault develops within the Cambrian strata,NW inclining with a dipping angle of 60°-80°.The Chuhe fault mainly dives NW direction with a dip angle of 50°-70°.In the Sujiawan-Xiage area,particularly,at a distance of 4-6 km to the SE of its main fault section,there is a concealed fault dipping SE with a dip angle of 60°-70°.The buried depth of the intrusive rock masses is generally between 0.5 km and 1.5 km,with the Sinian and Cambrian carbonate strata as the main wall rocks.The developing subordinate faults within the Sinian strata,on the west side of the main section of the Huangpo fault,led to the significant occurrence changes of the strata.On the other hand,fold structures developed in the Cambrian carbonate strata on the southeast side of the Huangpo fault,in particular,are characterized by intensi

关 键 词：滁州褶冲亚带 黄破断裂 滁河断裂 重磁勘探 音频大地电磁测量法(AMT) 深部地质特征解译 矽卡岩型铜金矿 微细浸染型金矿 

分 类 号：P612[天文地球—矿床学]