云南省富乐铅锌矿床闪锌矿中微量元素地球化学特征——兼论深色闪锌矿富集Cd的原因

GEOCHEMICAL CHARACTER OF TRACE ELEMENTS IN SPHALERITE FROM FULE Pb-Zn DEPOSIT,YUNNAN PROVENCE

富乐铅锌矿床位于川滇黔铅锌多金属成矿域东南部,其闪锌矿中Cd含量居全国前列。单矿物常量分析表明闪锌矿内w(Fe)低,平均0.23%。微量分析和电子探针微区分析显示,微量元素w(B)主要为Cd 16 183×10-6,Cu 1 514×10-6;Ni 414×10-6;As215×10-6;Se 163×10-6;Ge 135×10-6;Ga 86×10-6;Sb 35×10-6;Ag 16×10-6,其次为Cr,Co,Mn,Ba,Ti,Sr,Mo等,其含量一般1×10-6～10×10-6。Cd与Cu,Ag,Sb,As,Ni等呈正相关。闪锌矿的颜色由这些微量元素共同引起,Ni使闪锌矿呈紫色,Cu使闪锌矿呈红色,Ga使闪锌矿呈黄色。Cd不影响闪锌矿颜色,Cd之所以在深色闪锌矿中相对富集,是因为Cd与引起闪锌矿颜色改变的这些微量元素含量正相关,它们同步进入闪锌矿的晶格。Fe因为含量过低,对闪锌矿颜色影响不明显。

The Fule Pb-Zn deposit is located in the southeast part of Sichuan-Yunnan-Guizhou lead-zinc polymetallic district. Based on systematic studies on major elements, trace elements, and electron probe X-ray microanalysis, following achievements have been obtained. The sphalerite trace elements areCd（16 183×10^-6）;Cu（1 514×10^-6）;Ni（414×10^-6）;As（215×10^-6）;Se（163 ×10^-6）;Ge（135×10^-6） ;Ga（86 ×10^-6 ） ; Sb（35×10^-6）; Ag（16×10^-6 ） ,and Cr, Co, Mn,Ba, Ti, Sr,Mo,average content of ×10^-6-10×10^-6. There is correlation among Cd and Cu,Ag,Sb, As,Ni. The variation of colors of sphalerite is caused by these trace elements,Ni induces purple, Cu red and Ga yellow. The enrichment of Cadmium in sphalerite is correlated positively with those trace elements,which enter into lattice of sphalerite and change the colors of sphalerite. In fact, the color becomes heavier as the trace elementsbecomes richer. However,Cd and Fe do not affect the color of sphalerite.