基于重磁场多尺度边缘检测的地质构造信息识别与提取——以铜陵矿集区为例  

Identification and extraction of geological structure information based on multi-scale edge detection of gravity and magnetic fields:An example of the Tongling ore concentration area

作　　者：严加永[1,2] 吕庆田[2,3] 陈明春 邓震[1,2] 祁光[1,2] 张昆[1,2] 刘振东[1,2] 汪杰[1,2] 刘彦[1,2] 

机构地区：[1]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质科学院地球深部探测中心,北京100037 [3]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 [4]中石化地球物理有限公司云南分公司,昆明650233

出　　处：《地球物理学报》2015年第12期4450-4464,共15页Chinese Journal of Geophysics

基　　金："十二五"国家科技支撑计划课题(2011BAB04B01);国家深部探测专项第3项目(SinoProbe-03);中国地质科学院基本科研业务费专项经费(YYWF201526);地质调查项目(1212011220243);国家自然科学基金项目(41574133;41104061)联合资助

摘　　要：重磁场是地下地质体密度、磁性分别响应的综合,蕴涵着丰富的地质构造信息,如何将其有效地提取出来是正确认识地下结构的关键环节.本文在总结重磁场构造信息提取研究进展的基础上,将构造信息提取突破口归结为重磁场的边缘增强与检测.通过构建理论模型,对常用的边缘检测方法开展了对比试验,并以长江中下游成矿带中的铜陵矿集区为例,开展了实际资料的处理和研究.获得以下认识和结论:(1)多尺度边缘检测方法较其他方法更能准确提取模型边界,更适合于构造信息识别与提取;(2)在铜陵矿集区识别出18条断裂构造,确定了铜陵隆起的边界,断裂构造的走向主要为北东向,前人所谓"棋盘格式"断裂构造系统并不存在;(3)圈定了岩体的分布范围,在铜陵矿集区北缘,发现了2处隐伏岩体;(4)施家冲、戴家汇岩体周边是寻找矽卡岩型、斑岩型铜金矿的有利地段,铜陵隆起和繁昌火山岩盆地分界断裂两侧是寻找热液型铅锌矿和金矿的重要靶区.Gravitational and magnetic fields are the integrated response of density and magnetismof subsurface geological bodies,which contain abundant information about geological structure.How to identify and extract them effectively is the key to understand subsurface structure.Based on summary of the research progress in structural information extraction of gravitational and magnetic fields,we attributed such effort to the edge enhancement and detection of gravitational and magnetic fields.The contrast experiment of common methods of edge detection on a theoretical model shows that the multi-scale edge detection method can accurately delineate the boundary of the model from the gravitational and magnetic anomalies.It is proved that this method is suitable for recognition and extraction of structural information.Finally,we applied this method to the actual processing of gravity and magnetic data acquired from the Tongling ore concentration area,the middle and lower reaches of the Yangtze River.The results reveal the main structural faults and determine the edge of the Tongling uplift.These faults trend mainly in the northeast direction and the so called ＂checkerboard＂-like fault system does not exist.We delineated the distribution boundary of plutons according to multi-scale edge detection and found2 canceled plutons in the north of the Tongling ore concentration area.We predicted that the surrounding of Shijiachong and Daijiahui plutons are the prospective targets for skarn-type and porphyry-type copper or gold deposits.And both sides of the fault between the Tongling uplift and Fanchang volcanic basin are important target areas for hydrothermal-type lead-zinc and gold deposits.In summary,the research results show that multi-scale edge detection of gravitational and magnetic fields can provide much information for recognizing regional tectonics and prospecting prediction.This work also indicates that this method can be applied to similar fields.

关 键 词：重磁场 多尺度边缘检测 构造 识别与提取 铜陵矿集区 

分 类 号：P631[天文地球—地质矿产勘探]