摘要
茫崖河东金矿位于东昆仑成矿带西段祁漫塔格地区,属于典型的浅覆盖区,也是重要的金及多金属矿成矿集中区。为了实现该区金矿找矿突破,开展了1∶2.5万地球化学测量工作,圈定金异常63处,以Au为主元素的综合异常5处。利用数理统计方法对Au、As和Sb这3种元素进行变异系数、相关性分析和聚类分析,结果显示:Au异常分布不均匀,离散程度较大,为主要成矿元素。通过开展1∶1万土壤测量及异常查证工作,结合成矿地质条件和矿化特征,新发现含构造金蚀变带5条,带内圈定金矿体18条,矿床规模已达中型,构造叠加晕分析显示主矿体向深部延伸空间较大。研究表明:在茫崖河东地区开展不同尺度的地球化学测量工作,能够快速、准确地圈定金矿找矿靶区及矿化蚀变范围,取得了显著的找矿效果,能够有效评价深部找矿前景,是行之有效的找矿方法组合,可为同类型金矿找矿工作提供重要参考,值得推广应用。
The Eastern Kunlun Metallogenic Belt is recognized as one of the most significant gold ore concentration regions in both Qinghai Province and China as a whole.The eastern segment of this belt is home to prominent gold fields such as Wulonggou,Kaihuangbei,and Gouli,whereas the western segment contains fewer and smaller-scale deposits.The Mangyahedong gold deposit,situated in the Qimantage area within the western segment of the Eastern Kunlun Metallogenic Belt,exemplifies a typical shallow coverage zone and serves as a crucial metallogenic concentration area for gold and polymetallic mineralization.To facilitate advancements in gold exploration within this region,geochemical surveys at a 1∶25000 scale were conducted,identifying 63 gold anomalies and 5 composite anomalies predominantly characterized by gold.These gold anomalies are primarily located along the Mangyahedong-Hongweishan Heishigou zone,forming a NW-SEtrending banded pattern that aligns with the orientation of regional fault structures.The anomalies exhibit high intensity,often displaying a three-tiered concentration zonation.An analysis of elemental enrichment characteristics indicates that the coefficients of variation(CV)for Au,As,and Sb all exceed 2.0,suggesting strong differentiation(e.g.,the CV for Au in OSQ_(2)reaches 12.12).The enrichment coefficients(EF)exceed 2.0,indicating enriched conditions.The pronounced degree of enrichment and the marked heterogeneity in element distribution suggest a substantial potential for mineralization.Cluster analysis reveals that the F4 factor encompasses Au and As,with loadings surpassing 0.7,indicating an association with low-temperature tectonic activity.Analysis of elemental content across geological units indicates that the OSQ_(2)stratum(altered andesitic basalt)has an average Au content of 5.4×10^(-9),which is nearly three times the regional average.Subsequent soil surveys at a 1∶10000 scale identified 12 composite anomalies primarily characterized by Au and Cu,notable for their extensive scale,high intensity,and strong reproducibility.For example,the AP3 Au anomaly spans 0.36 km2 with a peak value of 1890×10^(-9)and shows a strong spatial correlation with As and Sb.Follow-up verification of key anomalies revealed promising indicators of gold mineralization.Within the GA11-Jia1 Au anomaly(AP1-AP3),five gold-bearing structural alteration zones were identified through surface tracing and trench drilling.These zones extend 0.5~5.2 km in length and 0.8~9.9 m in width,trending NW and dipping SW.Fourteen gold orebodies have been delineated,exhibiting lengths ranging from 140 to 1300 m,true thicknesses between 0.80 and 9.34 m,and grades of 0.8 to 26.4 g/t,with an average grade of 2.27 g/t.Structural superimposed halo analyses reveal that proximal halos near the main orebody at depth display inner/strong zone anomalies,whereas leading halos are characterized by outer zones and tail halos by mid-inner zones.This suggests a significant downward extension of the orebodies or the potential presence of blind orebodies at depth.In conclusion,multi-scale geochemical surveys conducted in the Mangyahedong area have proven effective in delineating gold exploration targets and alteration zones,thereby demonstrating substantial prospecting efficacy and facilitating a robust assessment of deep mineralization potential.This methodological approach serves as a practical exploration strategy and offers critical insights for the exploration of analogous gold deposits,with wide applicability and significant promotional value.
作者
马文君
谢海林
李少南
王斌
韩玉
李培庚
陈苏龙
王震
李斐斐
马海云
MA Wenjun;XIE Hailin;LI Shaonan;WANG Bin;HAN Yu;LI Peigeng;CHEN Sulong;WANG Zhen;LI Feifei;MA Haiyun(The First Geological Exploration Institute of Qinghai Province,Haidong 810600,Qinghai,China;Qinghai Engineering Research Center of Deep Exploration Technology for Large and Ultra-large Gold Deposits Around Qaidam Basin,Haidong 810600,Qinghai,China)
出处
《黄金科学技术》
北大核心
2025年第4期717-734,共18页
Gold Science and Technology
基金
青海省地质矿产勘查开发局基金项目“东昆仑奥陶纪钴矿成矿环境及找矿潜力”(编号:青地矿科[2024]67号)
“青海省格尔木市长山—红卫山地区1∶2.5万地球化学测量”(编号:青地矿科[2022]6号)联合资助。
关键词
地球化学测量
成矿地质条件
找矿靶区
找矿效果
茫崖河东金矿
东昆仑
geochemical measurement
metallogenic geological condition
prospecting target area
prospecting effect
Mangyahedong gold mine
Eastern Kunlun
作者简介
马文君(1987-),男,青海海东人,高级工程师,从事战略性矿产勘查及研究工作。E-mail:414425506@qq.com;通信作者:李少南(1985-),男,宁夏吴忠人,高级工程师,从事金矿矿产勘查工作。E-mail:690226320@qq.com;通信作者:陈苏龙(1982-),男,甘肃定西人,高级工程师,从事矿产勘查及管理工作。E-mail:115507653@qq.com。
