摘要
研究区位于北西向垭都—蟒洞构造带中部,区内铜矿山、海坝和篾匠冲3个矿段发现零星铅锌氧化矿、硫化矿、硫铁矿和多个褐铁矿体,其中海贝矿段曾通过物探TEM发现较大铅锌氧化矿体,其成矿条件与临区猪拱塘超大型铅锌矿床相似,分析深部找矿潜力巨大,因地形、信号干扰和物探方法勘探深度的局限性,后期找矿进展缓慢。本文总结分析了该区以往找矿勘查存在的难点,结合研究区地质背景特征,系统对岩(矿)石进行物性测量和分析发现,硫化矿石在频率0.1~10 Hz表现为高相位高极化率异常,异常强度大,与地层差异凸显,能有效压制地层带来干扰异常;在此基础上设计长周期大极距激电扫面探测,引入η/ρ绘制等值线平面异常进行异常划分,有效压制了高阻高极化异常,发现了不同强度的低阻高极化异常13个,对其中条带状(6)号中高极化低阻异常进行扩频激电法双边三极测深验证显示,深部YC74-1板状高极化率异常明显,异常位于高低电阻率密集接触带,极化率异常强度大,与围岩差异明显,推断该异常由深部硫化矿引起。钻孔验证发现深部隐伏硫铁矿体,矿体直接产出F_(0)断层破碎带中,赋矿围岩为二叠系栖霞组灰岩—泥盆系高坡场组白云质灰岩,矿体真厚3.33~12.47 m,平均厚7.65 m,Ts:17.32%~42.57%,Ts平均:28.54%,矿体埋深310.50~472.18 m。其中ZK74-2钻孔深度692.38 m见细脉状铅锌硫化矿,矿体真厚4.00 m。找矿实践证明,根据系统的电性测试结果,合理设计激电不同装置组合探测,可以在该区硫化矿的勘查中获得较好找矿效果。
The research area is located in the central part of the northwest trending Yadu-Mangdong tectonic belt.Multiple sporadic Pb-Zn oxide,Pb-Zn sulfide,pyrite,and limonite deposits have been discovered in the Tongkuangshan,Haiba,and Meijiangchong ore sections within the area.Among them,the Haibei ore section has previously discovered a larger Pb-Zn oxide deposit through TEM method,and its mineralization conditions are similar to the giant Pb-Zn deposit in the nearby Zhugongtang area.Analysis shows that there is huge potential for deep exploration.However,due to limitations in terrain,signal interference,and the depth of current geophysical exploration method,the progress of exploration in the later stage is slow.This paper summarizes and analyzes the difficulties existing in the previous mineral exploration in this area.It systematically collects and measures the physical properties of rocks(ores)by combining the geological background characteristics of the exploration area,and finds that the sulfide ores in frequency 0.1-10 Hz band show high phase and high polarization anomalies,with large anomaly intensity,and the differences with the strata are highlighted,which can effectively suppress the interference anomalies brought by the strata;on this basis,we designed an IP exploration with long-cycle current sources and large pole distance,and introduced a parameterη/ρto plot contour map for anomaly delineation,effectively suppressed the high-resistivity high-polarization anomalies,and discovered 13 low-resistivity highpolarization anomalies with different intensities,and verified the low-resistivity high-polarization anomalies in strip No.6 with forward and inverse pole-dipole sounding of the spread-spectrum induced polarization method,which showed that the high-polarization anomaly of the deep YC74-1 plate was obvious,and the anomaly was located in the dense high-and low-resistivity contact zone,and the intensity of polarization rate anomaly was high,with obvi⁃ous difference from the surrounding rocks,and it is assumed that the anomaly is caused by sulfide ore in the deep part.The drill holes verified the hidden sulfide ore body in the depth,the ore body is directly produced in the F_(0) fault fracture zone,and the surrounding rocks are limestone of Permian Qixia Formation to dolomitic graywacke of the Devonian Gaopaoba Formation,the true thickness of the ore body is 3.33-12.47 m,the average thickness is 7.65 m,the Ts is 17.32%-42.57%,and the average Ts is 28.54%,and the burial depth of the ore body is 310.50 m-472.18 m.There is fine vein-like lead-zinc sulfide ore at the drill hole depth of 692.38 m of ZK74-2,the true thickness ore body is 4.00 m.The practice of discovering ore bodies proves that,according to the electri⁃cal test results of the rock and ore samples,the reasonable design of the induced polarization method with different array combination for prospecting can have better effect of finding deposits in the exploration of sulfide ores in this area.
作者
卢卯
陈儒军
邓耀辉
黄凯
农观海
蒲庆隆
LU Mao;CHEN Rujun;DENG Yaohui;HUANG Kai;NONG Guanhai;PU Qinglong(Institute of Geological and Mineral Exploration,Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang 550005,Guizhou,China;School of Geoscience and Info-Physics,Central South University,Changsha 410083,Hunan,China;AIoT Innovation and Entrepreneurship Education Center for Geology and Geophysics,Central South University,Changsha 410083,Hunan,China;The Key Laboratory of Nonferrous Metal Mineralization Prediction and Geological Environment Detection of Ministry of Education,Changsha 410083,Hunan,China;Hunan Key Laboratory of Non-ferrous Resources and Geological Disaster Exploration,Changsha 410083,Hunan,China)
出处
《矿产勘查》
2024年第9期1671-1682,共12页
Mineral Exploration
基金
贵州省自然资源厅毕节试验区优势矿产资源大普查项目“毕节试验区赫章县垭都铅锌矿外围普查”(2130810)资助。
关键词
垭都
硫铁矿
铅锌矿
扩频激电
双边三极
Yadu
sulfide iron deposit
lead-zinc deposit
spread-spectrum induced polarization
forward and inverse pole-dipole
