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文章对西藏玉龙斑岩铜钼矿含矿斑岩体及外围岩体进行了系统的锆石Hf同位素原位分析,测得玉龙含矿斑岩体的176Hf/177Hf值为0.282681～0.282884,εHf(t)为1.60～4.86,矿区外围北部甘龙拉石英二长斑岩岩体176Hf/177Hf值为0.282812～0.282884,εHf(t)为2.39～4.92,矿区外围南部的纳加扎Y3石英二长斑岩岩体176Hf/177Hf值为0.282449～0.282894,εHf(t)为0.81～10.51,Hf同位素测试结果与亏损地幔地球化学储库的Hf同位素特征较为相似,表明本区成矿斑岩的源岩或源区可能来自亏损地幔,结合区域地球物理资料,认为玉龙斑岩铜矿带斑岩体是由软流圈上涌及其诱发的强烈底侵作用,使得本区地壳增厚继而发生部分熔融而形成。
The systematic zircon Hf isotopic analysis of zircons in the Yulong porphyry copper-molybdenum ore-bearing porphyry and its surrounding rocks in Tibet shows that the 176Hf / 177Hf values of the Yulong-bearing porphyry are 0.282681 ~ 0.282884 and εHf t) ranged from 1.60 to 4.86. The 176Hf / 177Hf value of the Kamullala quartz porphyrite in the northern part of the mine area ranged from 0.282812 to 0.282884 and the εHf (t) ranged from 2.39 to 4.92. The Nagarza Y3 quartz spot The 176Hf / 177Hf values of the rock mass range from 0.282449 to 0.282894 and the εHf (t) ranges from 0.81 to 10.51. The Hf isotopic results of the Hf isotope test are similar to those of the depleted mantle geochemical reservoir, indicating that the source rocks or The source area may come from the depleted mantle. Combined with the regional geophysical data, it is considered that the porphyry in the Yulong porphyry copper belt is caused by the upwelling of the asthenosphere and the strong underplating induced by it, which makes the crust thicken and then partially melted form.