高精度磁测在柴达木盆地北缘三角顶金矿床找矿中的应用  

Application of high precision magnetic survey in the gold prospecting Sanjiaoding area in the north margin of Qaidam Basin

作　　者：周豪 李善平[2] 王亚栋[2] 逯永卓 张鑫利[2] 封建平[2] ZHOU Hao;LI Shanping;WANG Yadong;LU Yongzhuo;ZHANG Xinli;FENG Jianping(Department of Geological Engineering,Qinghai University,XiNing 810000,Qinghai,China;Qinghai Geological Survey Institute Key Laboratory of Geological Processes and Mineral Resources in Northern Qinghai-Tibet Plateau of Qinghai Province,Xining 810012,Qinghai,China)

机构地区：[1]青海大学地质工程系,青海西宁810000 [2]青海省地质调查院青海省青藏高原北部地质过程与矿产资源重点实验室,青海西宁810012

出　　处：《矿产勘查》2024年第6期999-1006,共8页Mineral Exploration

基　　金：国家重点研发计划项目(2021YFC2901902)资助。

摘　　要：三角顶金矿床位于柴北缘结合带滩间山岩浆弧,是区域造山型金矿成矿事件响应的产物;研究区主要出露寒武系—奥陶系滩间山群火山岩组,岩性主要为玄武岩、硅质岩等;岩浆活动强烈,主要为晚泥盆世花岗闪长岩、二长花岗岩等,岩体中发育辉绿岩脉、石英脉等;基性—酸性岩中磁性由强变弱,其中辉长岩、二长花岗岩磁化率最高分别为8815.6×10^(-6)×4π·SI、5992.4×10^(-6)×4π·SI,可能由磁铁矿化、黄铁矿化引起强磁化率;磁异常呈锯齿状不规则跳跃,强度中等,梯度变化大,幅值为-733~820 nT;高精度磁法测量对与金矿成矿关系密切的断裂构造、破碎蚀变带等地质体有较好的分辨效果,经高精度磁法探测出局部异常呈串珠状分布,沿异常轴部存在断裂构造。经部分工程验证,在区内圈定构造蚀变带12条、金矿体7条、金矿化体40余条,M18-2异常与区内化探异常、深部工程验证等找矿信息相吻合,为区内进一步金矿找矿方向提供了依据。The Jiangding gold deposit is located in the magmatic arc of the interbank mountains in the junction zone of the northern margin of Qaidam,and is the response product of regional orogenic gold mineralization events.The volcanic rocks of the Cambrian-Ordovician Tanjianshan Group are mainly found in the study area,and the lithology is mainly basalt and siliceous rock.The magmatic activity is strong,mainly in the Late Devonian granodiorite,monzonitic granite,diabase veins,quartz veins,etc.The magnetic properties of basic-acid rocks change from strong to weak,and the highest magnetic susceptibility of gabbro and monzonitic granite is 8815.6×10^(-6)×4π·SI and 5992.4×10^(-6)×4π·SI respectively,which may be caused by magnetization and pyritization.The magnetic anomalies showed jagged irregular jumps with moderate intensity and large gradient variation,ranging from-733 to 820 nT.The high precision magnetic method can distinguish the fault structure and the fracture alteration belt which are closely related to gold mineralization.The high precision magnetic method can detect the distribution of local anomalies in beaded shape,and there are fault structures along the anomaly axis.Through some engineering verification,12 structural alteration zones,7 gold orebodies and more than 40 gold mineralized bodies have been delineated in the area.The M18-2 anomaly is consistent with the geochemical anomaly and deep engineering verification,which provides a basis for further gold prospecting direction in the area.

关 键 词：金矿床 石英脉型 高精度磁测 应用效果 三角顶 

分 类 号：F426.1[经济管理—产业经济]