广西三黎Pb-Zn矿床闪锌矿元素地球化学研究

Element Geochemistry and Its Significance of sphalerite from Sanli Pb-Zn Deposit in the Guangxi Zhuang Autonomous Region

三黎矿床位于广西大明山地区中部，为一个产于寒武系砂页岩中的石英脉型Pb-Zn矿床。为了查明矿床成因，笔者对该矿床中闪锌矿利用ICP-MS开展了微量元素（含稀土元素）地球化学研究。结果表明，闪锌矿富集Mn（136.40~23520×10-6）、Cu（69.11~1263.00×10-6）、As（90.48~1090.00×10-6）、Cd（2549.00~12990.00×10-6）、Pb（0.41~349.20×10-6）和In（36.87~36690.00×10-6）等元素；闪锌矿的Ga/In比值介于0.01~11.03之间，均值为3.70；Zn/Cd比值变化于43.36~201.29之间，均值为107.15。闪锌矿的稀土元素含量较低（1.02~5.43×10-6），富集轻稀土（LREE/HREE=2.92~13.79），弱的Eu和Ce的负异常（δEu=0.67~1.08和δCe=0.57~1.02）；Y/Ho比值变化较大，介于22~69.67之间，均值为34.94；在球粒陨石标准化的配分模式图上，稀土配分曲线整体呈右倾弱Eu和Ce负异常的模式。三黎Pb-Zn矿床属岩浆热液型矿床，形成于中低温、富F、还原的成矿环境，其深部具有寻找隐伏矽卡岩型Pb-Zn矿体和石英脉型W矿体的潜能。

The Sanli deposit, located in the central part of the Damingshan areas, Guangxi Zhuang Autonomous Region, is a quartz-vein type Pb-Zn deposit hosted by a set of sandstone and shale in age of Cambrian. In order to clarify its ore genesis, mineral element geochemistry （including rare earth element and yttrium） of sphalerite from the Sanli deposit are studied by ICP-MS in this study. The sphalerite from the Sanli deposit is enriched in Mn （136.40~23520×10-6）, Cu （69.11~1263.00×10-6）, As （90.48~1090.00×10-6）, Cd （2549.00~12990.00×10-6）, Pb （0.41~349.20×10-6） and In（36.87~36690.00×10-6）;the Ga/In ratios vary from 0.01 to 11.03, with a mean value of 3.70;and the Zn/Cd ratios range from 43.36 to 201.29, with an average of 107.15. Besides, the sphalerite from this deposit is depleted in rare earth element （1.02~5.43×10-6） and yttrium, and enrich in LREE （LREE/HREE=2.92~13.79）, with slight Eu and Ce negative anomalies （Eu=0.67~1.08和δCe=0.57~1.02）;and the Y/Ho ratios range from 22 to 69.67, with a mean value of 34.94. Those sphalerite from the Sanli deposit display a LREE-rich rare earth element and yttrium pattern in the chrondrite-normalized diagram. Combined ore geological and geochemical data, we conform that the Sanli deposit are form in the medium and low temperature with a F-rich ore forming fluid;and the Sanli deposit should be a magmatic-hydrothermal origin and displays a huge ore prospecting potential, especially, concealed skarn Pb-Zn and quartz vein W ore body.