西藏查藏错铜铅锌矿床成因:C-H-O-S-Pb同位素制约

查藏错铜铅锌矿床是近年来在冈底斯成矿带北亚带西部林子宗群火山岩中发现的一个铜多金属矿床.到目前为止，对其矿床成因还缺乏明确的认识.C、H、O、S、Pb同位素分析结果表明:δ13C_V-PDB值为-5.60‰~-2.40‰，δD_V-SMOW值为-111.00‰~-68.00‰，δ18O_V-SMOW值为-8.65‰~0.27‰，显示成矿流体早期主要来自岩浆热液，后期大气降水有所混入.δ34S_CDT值集中分布在0.50‰~2.50‰，具塔式分布特征，表明硫的来源为相对单一的岩浆源.Pb同位素比值较为稳定，μ值较大(>9.58)，具有上地壳铅源的特征，与冈底斯成矿带北亚带矿床矿石硫化物的铅同位素特征比较相似，但明显不同于典中组火山岩的铅同位素特征，推测成矿物质主要来自上地壳的岩浆源.结合矿床地质特征，并与国内外典型岩浆热液脉型矿床对比，认为其属岩浆热液脉型矿床. 

Genesis of Chazangcuo Cu-Pb-Zn Deposit,Tibet:Constraints from C-H-O-S-Pb Isotope Geochemistry

Chazangcuo Cu-Pb-Zn deposit, hosted by the Linzizong Group volcanic rocks in the west of Gangdese metallogenic belt, is a copper polymetallic deposit discovered in recent years. So far, the genesis of the deposit is still lack of clear understanding. The results of C, H, O, S, Pb isotopic analysis show that the δ13C_V-PDB values range from -5.60‰ to -2.40‰, δD_V-SMOW values range from -111.00‰ to -68.00‰, and δ18O_V-SMOW values range from -8.65‰ to 0.27‰, indicating that the ore-forming fluid mainly derived from the magma hydrothermal in the early time, however, with the mineralization continuing, the proportion of atmospheric precipitation gradually turned larger. δ34S_CDT values range from 0.50‰ to 2.50‰ and possess the distribution characteristics of tower, indicating that the sulfur isotope derived from the single magma source. Lead isotope ratios are relatively stable and have large μ values (more than 9.58), possessing the characteristics of the upper crust lead. The lead isotope characteristics are similar to the ore sulfides from the deposits in the north subzone of Gangdese metallogenic belt, but obviously different from the lead isotope characteristics of volcanic rocks of Dianzhong Formation. Therefore, the authors infer that the source of ore-forming materials mainly came from the magmatic source of the upper crust. Combining with the geological characteristics of Chazangcuo deposit, and contrasting the typical magmatic hydrothermal vein-type deposit at home and abroad, the authors think that it belongs to the typical magmatic hydrothermal vein-type deposit.