为了探讨西藏墨竹工卡县洞中拉铅锌矿的成矿物质来源,研究矿床成矿机制,对该矿床的矿石样品进行了硫和铅同位素分析,并对其变化规律和成因意义进行讨论.研究结果表明,6件金属硫化物样品(闪锌矿、黄铜矿、方铅矿)的δ34S值变化于2.2‰～4.8‰之间,显示硫同位素组成比较稳定.根据共生硫化物对所确定的温度,该矿床属中低温热液矿床.6件金属硫化物样品206 Pb/204 Pb、207Pb/204Pb和208Pb/204Pb变化范围分别为18.628 0～18.629 6、15.698 0～15.699 9、39.077 5 ～39.082 4,平均值分别为18.628 70、15.699 02和39.079 37.硫和铅同位素研究结果表明,洞中拉铅锌矿床的硫主要来自沉积围岩,主要为无机还原成因,有少量硫来自本地区燕山晚期花岗岩;洞中拉铅锌矿床矿石铅主要来自上地壳物质.%In order to discuss the ore-forming material sources of the Dongzhongla Pb-Zn deposits and study the metallogenic mechanism, we analyzed the sulfur and lead isotope from the orebody, discussed the changing regularity and significance. The results show that the δ34S values of the six metal sulfides vary from 2. 2%c to 4. 8%e, and that the sulfur isotope composition is stable. The temperatures calculated from sulfide-paras show that the deposits are the middle-low temperature deposits. The 206Pb/204Pb,207Pb/204Pb and 208Pb/204 Pb ratios of 6 sulfide samples of orebody vary in ranges of 18.628 0 - 18.629 6, 15. 698 - 15. 699 9, 39.0775 -39. 082 4, with the average values of 18. 628 7, 15. 699 02 and 39. 079 37, respectively. The results of sulfur and lead isotope show that the ore-forming materials of Dongzhongla Pb-Zn deposits came from the Permian volcanic sedimentary rock and late Yanshan period granite.
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