Orefield Structural Analysis And Prediction Of Yinkeng Pb-Zn-Ag Ore-field In The South Jiangxi Region

The Yinkeng deposit, located in the east part of the Yudu-Ganxian ore field, isone of the most important Pb-Zn-Ag deposits in the east part of the Nanlingmetallogenic belt. The ore bodies in the shallow place is insufficient to the continuingexploitation, thus the exploration in the deep place is severely needed. Structure in oredeposit is regarded as a key factor to ore mineralization and is of importance for oreprospecting.On the basis of detailed field observation and geological mapping, this paperpresents several new achievements about geological features of the deposit. Forexample, we finished the map of structures and ore bodies of the deposit on a scale of1:10000, analyzed the geometrical features of the joints and sedimentary strata,determined bulk-rock and H-O isotopic composition for the deposit.The Qiaozikeng-Shuangyuankeng is a synclinoriumis whose axial plane is in thedirection of282°and trending towards84°and whose hub is in the direction of31°tonorth and in the direction of173°to the south. The Qinzikeng is a synclinoriumiswhose axial plane is in the direction of254°and dipping to88°with its axial plane inthe direction of350°, dipping to10°, classifying them to the extruded steep closedfolds.The nappe structures F1and F2in the ore deposit trusted in the first period butthen glissaded. The north parts of faults are in the direction of36°with a dip angle of52°, whereas the south parts are in the19°with a dip angle of75°. The F5fault can bedivided into the north part and south part. The north part is north trending withsteeping compressional schistosity belt, whereas the south part is northeast trendingwith a dip angle of60°.The directions of the compressional stress in the ore deposit changed fromNW-SE to NWW-SEE, then to NNE-SSW, and finally to NEE-SWW during theIndosinian–Yanshanian on the basis of geometrical analyses of the joints. Most of thejoints of the study area are in the direction of290～320°. Additionally, the north trending Au-Cu-Pb-Zn bearing tectonic-metallogenicbelts are also observed in our study. Trace element and H-O isotopic analysis indicatethat these ore bodies have different mineralization types to other ore bodies in thesame deposit. these ore bodies are better prospecting target.