The Zhunuo porphyry copper deposit in the Gangdese belt of southern Tibet contains 2.37 Mt at 0.57% Cu. In this deposit, Eocene rhyolite (51.6 ± 1.0 Ma) and quartz porphyry (49.1 ± 0.6 Ma) were intruded by monzogranite (14.7 ± 0.3 Ma) and monzogranite porphyry (14.5 ± 0.2 Ma) which commonly host mafic microgranular enclaves (14.9 ± 0.3 Ma). Late-mineralization diorite porphyry (14.2 ± 0.2 Ma) and post-mineralization lamprophyre dikes (12.2 ± 0.1 Ma) and granite porphyry (12.0 ± 0.2 Ma) crosscut the Miocene intrusions. Two quartz–molybdenittie veins yielded molybdenite Re-Os model ages of 14.8 ± 0.1 Ma and 14.4 ± 0.1 Ma, and another two quartz–muscovite–llite–pyrite–molybdenite veins yielded molybdenite Re-Os model ages of 14.2 ± 0.1 Ma and 13.5 ± 0.1 Ma. Zhunuo is characterized by early potassic alteration and associated quartz A veins centered on the monzogranite porphyry and adjacent monzogranite, distal propylitic alteration in the rhyolite, and late-stage phyllic alteration and associated quartz B veins, followed by D veins that affected quartz porphyry and potassic-altered rocks. Copper ores are mainly distributed in the potassic alteration zone that was overprinted by phyllic alteration. Copper mineralization likely occurred during potassic alteration stage and was locally remobilized and redeposited during phyllic alteration stage, or occurred during phyllic alteration stage. The post-mineralization granite porphyry has lower whole-rock Sr/Y (< 20) and ε Nd (t) (− 9.3 to − 9.0) and higher zircon U/Yb (4 to 27) than the Miocene intrusions (Sr/Y > 40; ε Nd (t) = − 6.9 to − 6.1; U/Yb = 1 to 10). Limited input of juvenile melts could explain the low potential for copper mineralization in the post-mineralization granite porphyry at Zhunuo.

中文翻译：

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藏南冈底斯带朱诺斑岩铜矿地质及成因

藏南冈底斯带朱诺斑岩铜矿床含铜2.37 Mt，铜含量0.57%。在该矿床中，始新世流纹岩（51.6±1.0 Ma）和石英斑岩（49.1±0.6 Ma）被二长花岗岩（14.7±0.3 Ma）和二长斑岩（14.5±0.2 Ma）侵入，二长斑岩（14.5±0.2 Ma）通常是镁铁质微粒（10.43.9嘛）。晚成矿闪长斑岩 (14.2 ± 0.2 Ma) 和后成矿斑岩 (12.2 ± 0.1 Ma) 和花岗岩斑岩 (12.0 ± 0.2 Ma) 横切中新世侵入体。两条石英-辉钼矿脉产生的辉钼矿 Re-Os 模型年龄分别为 14.8 ± 0.1 Ma 和 14.4 ± 0.1 Ma，另外两条石英-白云母-伊利石-黄铁矿-辉钼矿脉产生的辉钼矿 Re-Os 模型年龄分别为 14.2 ± 0.1 Ma 和 135 Ma。 ± 0.1 毫安。朱诺以二长斑岩及相邻二长花岗岩为中心的早期钾蚀变及伴生石英A脉，流纹岩远期青纹岩蚀变，晚期叶状蚀变及伴生石英B脉，其次为影响石英斑岩及钾质的D脉- 变质的岩石。铜矿主要分布在被叶系蚀变叠印的钾蚀带。铜矿化可能发生在钾蚀变阶段，在叶系蚀变阶段局部再动员和再沉积，或发生在叶系蚀变阶段。与中新世侵入体 (Sr/Y) 相比，矿化后的花岗岩斑岩具有较低的全岩 Sr/Y (< 20) 和 ε Nd (t) (− 9.3 至 − 9.0) 和更高的锆石 U/Yb (4 至 27) > 40；ε Nd (t) = − 6.9 至 − 6.1；U/Yb = 1 到 10）。年轻熔体的有限输入可以解释朱诺矿化后花岗岩斑岩中铜矿化的低潜力。