陕西勉县王家沟金矿区物化探勘查技术应用及找矿预测

通过对区域成矿规律研究,总结勉略宁三角区南部成矿带的找矿标志为:①地层为元古宇基底变质火山岩系及靠近该岩系的碎屑岩、碳酸盐岩沉积;②呈NE—NNE向的断裂构造活动发育;③沿构造充填的中基性—基性岩脉发育区;④Au、Ag、Cu、Zn等为代表的地球化学异常区。对研究区进行成矿条件分析,认为区内具有寻找与断裂构造有关金矿的有利条件。首先选用激电中梯法在矿区快速准确地圈定了Ⅰ、Ⅱ两个NE向平行排列的高极化率、中低电阻率异常带,然后垂直异常带布置了两条单极—偶极测深及土壤地球化学剖面,结合地质资料进行解译,预测这两个异常带是由两个隐伏的含矿断裂构造引起的。布置硐探工程进行验证,在Ⅰ号异常带下部发现一条含多金属硫化物的石英脉型金矿体,推测规模和强度均大于Ⅰ号的Ⅱ号异常带下部存在更大规模的金矿体。

The application of geophysical and geochemical exploration and metallogenic prediction in the Wangjiagou gold ore district of Mianxian County, Shaanxi Province

Based on a study of regional metallogenic regularity,this paper summarizes the prospecting criteria for the southern metallogenic belt in the Mian-Lue-Ning triangle area as follows: ① strata composed of Proterozoic basement metamorphic volcanic rocks and adjacent clastic rock and carbonate rocks;② well-developed NENNE trending faults;③ areas where fractures are filled with intermediate-basic veins;④ geochemical anomaly areas of such elements as Au,Ag,Cu and Zn.The authors analyzed the metallogenic conditions of the study area and considered that the study area had favorable conditions in search for gold deposits related to fractures.First,using the IP intermediate gradient method,the authors quickly and accurately delineated two parallel NE-trending anomaly zones(No.Ⅰ,No.Ⅱ) which had high polarizability and low resistivity,and then disposed two polarization pole-dipole array sounding and soil geochemical profiles perpendicular to the anomaly zones.Combining geological data with interpretation,the authors predicted that the two anomaly zones were caused by two concealed ore-bearing fractures.Using adit engineering under the No.Ⅰ anomaly zone,the authors found a quartz vein type gold ore body which contained polymetallic sulfides.It is thus inferred that there exists a larger gold ore body under the No.Ⅱ anomaly zone,which has stronger and greater anomaly intensity than No.Ⅰ.