安徽铜陵新桥铜硫铁矿床胶状黄铁矿主、微量元素特征

摘要

利用电子探针(EPMA)对安徽铜陵新桥铜硫铁矿床的胶状黄铁矿进行原位微区主、微量元素成分分析，研究结果表明：胶状黄铁矿的w(Fe)/w(S)为0.803~1.058、w(Co)/w(Ni)为0.571~79.000、w(S)/w(Se)为1650.656~8711.600、w(Zn)/[w(Zn)+w(Pb)]为0.027~0.460，胶状黄铁矿为热液成因，其形成温度高于结晶黄铁矿的形成温度；在胶状黄铁矿内部，元素Fe和S含量稳定，Cu和Pb在核部较为富集。在此基础上，对新桥矿区的黄铁矿进行主微量元素相关性分析，得出胶状黄铁矿中As可能以固溶体的形式出现，且早期成矿流体中As含量较为稳定，但后期成矿流体中As含量却逐步提高。%The contents of major and trace elements of colloidal pyrite in Xinqiao, Tongling, Anhui Province, China, were measured by EPMA. The analysis data suggest that w(Fe)/w(S), w(Co)/w(Ni), w(S)/w(Se) and w(Zn)/[w(Zn)+w(Pb)] of colloidal pyrite is from 0.803 to 1.058, 0.57 to 79.000, 1 650.656 to 8 711.600 and 0.027 to 0.460, respectively, which indicates that the colloidal pyrite forms because of hydrotherm, its forming temperature is higher than that of the crystal pyrite, the contents of Fe and S are consistent, and Cu and Pb enrich in the center of colloidal pyrite. On this basis, correlation analysis of major and trace elements of pyrites was carried out, and the results show that As in the colloidal pyrite might be in the from of solid solution, and the content of As in the early metallogenic hydrotherm is consistent , while the one in the late metallogenic hydrotherm increases step by step.