The Tiantang Cu-Pb-Zn polymetallic deposit of Guangdong Province occurs at the northeast edge of Yangchun basin, which is located in the Qinzhou-Hangzhou metallogenic belt. On the basis of geological field observations, the authors selected main sulfides in the deposit as the object to study the mineralogical characteristics, and analyzed the S-Pb isotopic composition so as to trace and discuss the sources of ore-forming metal materials. Representative results 1 of electron microprobe analysis show that Fe and S content and atomic ratios of S/Fe in pyrite are higher than theoretical values, there exist Cu, Sb and As, and the ratios of Co/Ni are between 0.21 and 2.28, usually higher than 1, suggesting a hydrothermal environment of relatively high sulfur fugacity; in sphalerite the Zn content is lower than theoretical values while the atomic ratios of S/Zn and the S content are higher than theoretical values, with the existence of some Pb, Fe, Co and Se; some elements in galena, chalcopyrite and other sulfides occur in isomorphism. Δ 34S values of the main ore minerals of this deposit have a narrow range of -2.1%o～2.6%o,with peaks at -0.8%o～0.4%o, showing tower-shaped distribution effect and features of magmatic sulfur. Lead isotopic compositions of ores are basically coincident, and 208Pb/204Pb, 207Pb/204Pb and 206Pb/204Pb ratios of ores vary from 38.765 to 39.137, 15.523 to 15.751 and 18.450 to 18.667, respectively. These lead compositions indicate that the ore-forming materials not only had features of the lower crust or the upper mandebut also had characteristics of the upper crust, indicating that there should have been several sources for ore-forming materials in the Tiantang deposit, belonging to crust-mande mixture, and the ore deposit was formed due to lithospheric extension in southern China since the Late Mesozoic.%广东天堂矽卡岩型铜铅锌多金属矿床位于钦州—杭州成矿带阳春盆地的东北端边缘.在野外地质观察的基础上,选取该矿床主要金属硫化物开展矿物学特征研究,测定S、Pb同位素组成,探讨其成矿物质来源.电子探针分析发现:黄铁矿中Fe、S含量和S/Fe原子比普遍高于理论值,存在一定量的Cu、Sb、As,Co/Ni比值变化范围为0.21～2.28,一般大于1,指示硫逸度较高的热液环境;闪锌矿中Zn含量比理论值稍低,S/Zn原子比和S含量较理论值偏高,含一定量的Pb、Fe、Co和Se等元素；方铅矿、黄铜矿等硫化物元素间均有类质同象现象的发生.硫化物的δ 34S组成范围比较窄,变化范围为-2.1‰～2.6‰,多数集中在-0.8‰～0.4‰,具有明显的塔式分布特征.矿石矿物Pb同位素组成亦比较稳定,208Pb/204Pb、207Pb/204Pb、206Pb/204Pb的变化范围分别为38.765～39.137、15.523～15.751、18.450～18.667,矿石铅既具有下地壳或者上地幔的特征,又具有上地壳的特征,显示混合源特征,表明成矿物质属于壳幔混合型,具有多种物质来源,可能是晚中生代以来华南地区岩石圈伸展作用的产物.
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