新疆若羌喀腊达坂铅锌矿床S同位素特征及找矿预测

S Isotope Characteristics and Prospecting Prediction of Kaladaban Pb-Zn Deposit in Ruoqiang County,Xinjiang

喀腊达坂铅锌矿床位于新疆阿尔金山脉东段喀腊大湾地区,矿床内矿体主要赋存于晚寒武世拉配泉组第二、三岩性段中。结合野外地质调查成果,选取了与成矿有关的硫化物样品进行S同位素示踪研究,结果表明:成矿流体w(^(34)S)大体为2.6‰~7.7‰,甚至小于2.6‰,硫化物的S同位素组成具有深源岩浆硫的特征。通过对矿区矿化蚀变特征、控矿要素及成矿地质体特征的研究,并结合S同位素特征,综合分析认为喀腊达坂铅锌矿床为受构造破碎带控制、与中酸性岩浆侵入作用有关的中低温热液型矿床,成矿时代为439.9 Ma。在此基础上构建了喀腊达坂铅锌矿床的找矿预测模型,即岩浆沿喀腊达坂断裂带及其分支系统上侵,在岩浆侵位及其流体出溶阶段派生出容矿断裂系统,其中主成矿断裂可能为成矿前断裂的再活动,分支断裂属于成矿期同生断裂,矿化类型为角砾岩带砾间充填型及其上盘裂隙带中的裂隙充填型。根据该模型开展了找矿预测及工程验证工作,在矿区及其外围共圈定了5个隐伏主矿体,新增了可观的Pb+Zn资源量,对于矿区后续找矿预测工作有一定的参考价值。

Kaladaban Pb-Zn deposit is located in the Kaladawan Area,which lies in the east part of Altyn Mountains in Xinjiang,the ore-bodies in the mining area are mainly hosted in the second and third lithology members of Late Cambrian Lapeiquan Formation.Combing with the field geological investigation results of the mining area,the sulphide samples related to mineralization are selected to carry out S isotope tracer study,the results show that w（34 S） value of metallogenic fluid is mainly from 2.6‰ to 7.7‰,especially for lowering than 2.6‰,the S isotopic composition of sulphide samples is characterized by deep source magmatic sulfur.The mineralized alteration characteristics,ore-controlling factor and characteristics of metallogenic geological bodies of the mining area are studied,combing with the S isotopic characteristics,the comprehensive analysis results indicated that the genesis type of Kaladaban Pb-Zn deposit is the medium-low temperature hydrothermal one that is related to intermediate-acid magmatic intrusion and controlled by structural fracture belts.Based on the above discussion results,the prospecting model of Kaladaban Pb-Zn deposit is established,the model can be described that the magma is invaded along the Kaladaban fault belt and its branch tectonic system,in the magmatic emplacement and its fluid release phase,the ore-bearing fracture system is developed,the branch faults is belongs to ones developed in the metallogenic period,the mineralization types is inter breccia filling type and fracture filling type developed in the fissure belts in the upper plate of breccia belt.Under the guiding of the prospecting model,some related prospecting prediction work and engineering verification works are conducted,about five main concealed ore-bodies are controlled in the mining area or its peripheral area,considerable Pb＋Zn resources are obtained,which can provide some reliable reference for the further prospecting work in the mining area.