广东省典型铅锌多金属矿床镉的分布特征

以广东省典型铅锌多金属矿床为例,探讨各矿区镉的含量特征及不同类型矿床闪锌矿中镉的含量及锌镉比值分布特点,结果显示,镉富集程度受不同矿区地球化学背景的影响较大;不同矿区镉与锌均表现出相关—强相关关系,表明两者在成矿过程中具有相似的地球化学特征;高镉含量与低锌镉比值叠合区主要位于已知铅锌矿床分布地段,向四周镉的富集程度有所降低;不同矿床的闪锌矿中,镉的富集系数及锌镉比值具明显阶梯性,除受控于闪锌矿的形成温度、颜色及类型外,还与矿区富银关系密切。该研究为了解广东省镉分布特征及镉矿地质评价工作提供了科学依据。

DISTRIBUTION CHARACTERISTICS OF CADMIUM IN TYPICAL Pb-Zn POLYMETALLIC DEPOSITS OF GUANGDONG PROVINCE

Exemplified by typical Pb-Zn polymetallic deposits in Guangdong Province,the authors studied the content characteristics of cadmium in various mining areas and the distribution characteristics of the cadmium content and w(Zn)/w(Cd) ratios in sphalerite from different types of ore deposits.The results show that different geochemical backgrounds in different mining areas have exerted great influences on the enrichment degree of cadmium.In various mining areas,Cd and Zn show correlation or even strong correlation,suggesting that they had similar geochemical characteristics during the ore-forming process.The superimposition of high cadmium content and low w(Zn)/w(Cd) ratios mainly occurs in the distribution areas of known Pb-Zn polymetallic deposits,and the enrichment degree of cadmium somewhat decreases in all directions.The enrichment coefficient of cadmium and w(Zn)/w(Cd) ratios in sphalerite from different types of ore deposits show obvious ladder-like variations,which were not only controlled by the temperature and color during the ore-forming processes of different types of sphalerite but also closely related to silver enrichment in the mining area.This study provides scientific basis for understanding distribution characteristics of cadmium and making geological evaluation of cadmium deposits in Guangdong Province.