西藏德新铅多金属矿床地球物理与地球化学综合找矿研究

Study on Geophysical and Geochemical Comprehensive Prospecting of Dexin Lead Polymetallic Deposit in Tibet

德新铅多金属矿床是冈底斯多金属成矿带西段受构造—岩浆控制的中—低温热液型多金属矿床之一。通过对岩(矿)石电阻率、极化率及主微量元素等物性参数和地球化学特征进行分析,综合解释矿区矿致异常,并利用多元统计分析方法对成矿元素进行研究。结果表明:德新铅多金属矿床矿体的极化率及电阻率与围岩存在明显差异,可划分为低阻高极化和高阻高极化2种类型,对应8处激电异常,推测JD3-5和JD4低阻高极化异常为矿致异常,具有深部找矿潜力,是区内找矿勘查的重点区域之一;Pb、Zn、Cu、Mo、Ni和In等元素相关性显著,是德新铅多金属矿床的主要成矿元素;成矿过程前期主要受中—高温岩浆热液矿化类型Zn-Mo-Pb和Cu-Ni-In的影响,后期主要受含有Sc-Cr-Li和Hf-Be元素的流体及围岩的影响,其中Pb元素受Ni、Mo和In影响强烈,Zn元素受Mo的影响强烈。上述认识能够为找矿预测提供有用的宏观及微观信息,对该区域综合找矿具有重要的指导意义。

Dexin lead polymetallic deposit is one of the midium-low temperature hydrothermal polymetallic deposits controlled by structure-magmatic in the western section of the Gangdese polymetallic metallogenic belt.In order to delineate the IP intermediate gradient anomaly in this area,find out the ore-forming elements combination and narrow the prospecting target area,the physical parameters of resistivity,polarizability,main and trace elements and geochemical characteristics of the rock(ore)in Dexin lead polymetallic deposit were analyzed,and the ore-forming anomalies in the mining area were comprehensively explained,and multivariate statistical analysis of ore-forming elements was carrid out.It is found that there are obvious differences in the polarization and resistivity between the orebody and surrounding rock in the Dexin lead polymetallic mining area.According to the apparent resistivity background,it can be divided into two types,namely low resistancehigh polarization and high resistance-high polarization.It is speculated that the low resistance-high polarization anomalies(JD3-5,JD4)are ore-induced anomalies with deep prospecting potential,which is one of the key areas for prospecting and exploration in the area.According to correlation,R-type clustering and principal component analysis,Pb,Zn,Cu,Mo,Ni,In and other elements have significant correlation,which are the main ore-forming elements in the Dexin mining area.The Dexin lead polymetallic deposit may have experienced multiple magmatic-hydrothermal geological processes at different stages of mineralization.The early stage was influenced by Zn-Mo-Pb and Cu-Ni-In mineralization of medium-high temperature magmatic-hydrothermal mineralization type,and the later stage was affected by fluid and surrounding rock including Sc-Cr-Li and Hf-Be elements.Through the multiple stepwise linear regression analysis of the main ore-forming elements Pb,Zn,Cu and Ni,it is concluded that Pb is strongly influenced by Ni,Mo and In,Zn is strongly influenced by Mo,Cu is significantly influenced by In and Pb,and the influence degree of Ni from large to small is In,Be,Sc and Zn.According to the empirical equation,it is found that the fitting effect is good,which can provide certain microscopic information for Pb polymetallic mineralization.This understanding can provide useful macro and micro information for prospecting prediction,and has important guiding significance for comprehensive prospecting in this area.