滇西南哀牢山构造带李子冲矿区综合物探的应用研究
Application of Comprehensive Geophysical Exploration in the Lizichong Mining Area,Ailaoshan Tectonic Belt,Southwest Yunnan Province
于慧敏 1沈晓丽 1苏虎虎 2贾文臣 3张宝林 4苏捷5
作者信息
- 1. 山东科技大学地球科学与工程学院,山东青岛 266590
- 2. 湖北省地质局冶金地质勘探大队,湖北十堰 442000
- 3. 中铁资源集团有限公司北京技术咨询分公司,北京 100039
- 4. 中国科学院地质与地球物理研究所矿产资源研究重点实验室,北京 100029
- 5. 红河州自然资源和规划局,云南红河 661100
- 折叠
摘要
云南省金平县李子冲铁铜矿区地处扬子板块与印支板块交接部位的哀牢山构造带南段,其外围已发现大量的铁铜矿床(点),是云南重要的铁铜矿产基地.但研究区高山植被覆盖严重,地形起伏较大,地质构造复杂,岩浆活动强烈,找矿困难.为克服单一勘探方法找矿的局限性,选择高精度磁法、双频激电法和EH4电磁测深法对矿区进行综合地球物理勘探,结合地质调查资料,对矿区构造、隐伏岩体及矿化体的深部延伸情况进行解译,并总结找矿信息.综合物探结果表明,矿化体主要在哀牢山群变质岩系产出,与基性侵入岩和花岗闪长岩体关系密切,并伴有多种矿化现象;铁矿化区显示高磁、低视电阻率、高视幅频率特征,铜矿化区则具有低磁、低视电阻率、高视幅频率特征.根据磁力线突变或弯曲变形的磁异常现象和低视电阻率的激电异常及EH4剖面测量解译结果,推测矿区可能存在形成时间较早的北西向张性断裂和形成时间较晚的北东向剪性断裂,近北西向断裂有利于成矿而近北东向断裂对矿体具有破坏作用.对矿区内激电异常与磁异常整体套合较好且EH4电磁测深揭露深部具有成矿潜力的位置进行工程验证,结果显示,矿体在深部具有一定程度的延伸,近北西向断裂构造及其次级构造是主要的赋矿区域,相对低缓的磁异常区域深部可能存在新的铁铜矿化体,有扩大储量的可能,这对下一步地质勘查工作具有指导意义.
Abstract
The Lizichong iron-copper deposit is located in the southern section of the Ailaoshan tectonic belt,between the Yangtze Plate and the Indian Plate in Yunnan Province.A large number of iron-copper deposits have been found in the periphery of this area,making it an important iron-copper mineral base in Yunnan Prov-ince.However,this study area is covered by alpine vegetation and has large topographic variations,complex geological structures,intense magmatic activities,making ore exploration challenging.To overcome the limita-tions of a single exploration method,we used high-precision magnetic method,dual-frequency IP methods,and EH4 electromagnetic sounding methods to conduct a comprehensive geophysical exploration in the mining area.Combined with a geological survey,the deep extension of the structure,buried magmatic rock and mineralized body in the mining area were interpreted,and the prospecting information was summarized.Comprehensive geo-physical results show that the mineralized bodies are mainly hosted in the metamorphic rock series in the Ailaos-han Group and are closely related to the basic intrusive rocks and the granodiorite porphyry rock with various types of mineralization.The iron-mineralized area shows high magnetism,low apparent resistivity and high ap-parent amplitude frequency,while the copper-mineralized area is characterized by low magnetism,low apparent resistivity and high apparent amplitude frequency.According to the magnetic anomalies of abrupt or bending de-formation of magnetic field lines,IP anomalies of low apparent resistivity and the measurement and interpretation results of EH4 profiles,there may be earlier-formed NW-trending tensile faults and subsequently-formed NE-trending shear faults.The NW-trending fault is conducive to mineralization,while the NE-trending fault is de-structive to the ore body.In the mining area,the positions with a good combination of IP anomalies and magnet-ic anomalies,and deep ore-forming potential revealed by EH4 electromagnetic sounding have been verified by engineering operations.The results show that the ore body,to some extent,extends into the deep,and that the NW-trending fault and its secondary structure are the main ore-bearing area.There may be new iron-copper mineralization bodies in the deeper locations with relatively low and gentle magnetic anomalies,which have the potential to expand the reserve.This has significance for further geological exploration.
关键词
哀牢山变质杂岩带/李子冲铁铜矿/高精度磁法/双频激电法/EH4电磁测深Key words
Ailaoshan metamorphic complex belt/Lizichong iron-copper deposit/high precision magnetic sur-vey/dual frequency induced polarization method/EH4 electromagnetic sounding引用本文复制引用
基金项目
山东省自然科学基金项目(ZR2023MD023)
山东省高等教育科技计划项目(J18KA213)
山东科技大学人才引进科研基金(2017RCJJ029)
出版年
2024
国家科技期刊平台
NSTL
万方数据