中文摘要：

黔西北铅锌成矿区内广泛发育中．小型铅锌矿床，这些矿床的分布严格受到区域性构造的控制，特别是北西向构造。本文以产于不同构造中典型矿床为代表，在分析和收集热液方解石、蚀变围岩和远矿围岩C-O同位素组成基础上，探讨成矿流体中C02可能的来源。结果显示，热液方解石C-0同位素组成介于海相碳酸盐岩和地幔C-0同位素组成之间，更靠近海相碳酸盐岩，同时热液方解石C和0同位素组成间略呈负相关关系，表明成矿流体中的c02来源比较复杂，可能地幔、沉积物有机质和海相碳酸盐岩都有贡献。不同矿床间热液方解石C-0同位素组成略有差别，可能与热液流体与不同矿床围岩间C-0同位素交换程度不同或各端元参与程度不同有关。本文分析显示系统的C-0同位素地球化学研究有望揭示成矿流体演化过程或约束不同端元贡献比例。

英文摘要：

More than 100 Pb-Zn deposits have been found in the NW Guizhou province, which are mainly structurally controlled by regional NW tectonic systems. This paper takes the typical Pb-Zn deposits in different tectonic system as examples, by analyzing C-O isotopic compositions of hydrothermal calcite, altered wall rocks and host rocks, discuss the sources of CO2 in the hydrothermal fluids. Results show that C-O isotopic compositions of hydrothermal calcite are between those of mantle and marine carbonates, but near marine carbonates, with a feature of negative correlation between 613CpDB and 518OsMow values. This indicates that sources of CO2 in the hydrothermal fluids are complex, and mantle, marine carbonates and organic matter may supply CO2. The δ13CpDB and 618Osuow values have a little differences among different deposits, suggesting that different contents of water/rocks reaction or degrees of participation of different end members. This study also suggests that the system research on C-O isotope can reveal the evolution of ore-forming fluids or contributions of different end members.