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普朗斑岩铜矿在中国斑岩铜矿床中有其特殊性,无论对中甸岛弧带的基础地质还是矿产资源评价预测的研究,都具有重要意义。然而,该斑岩铜矿床无确切的年代学数据。通过作辉钼矿Re-Os年龄和单矿物K-Ar年龄测定,首次确定了普朗斑岩铜矿床内具有钾硅酸盐化的黑云石英二长斑岩成矿作用的活动时间为(235.4±2.4)Ma～(221.5±2.0)Ma,石英-辉钼矿阶段的辉钼矿Re-Os年龄大致为(213±3.8)Ma,两者十分相近。表明普朗斑岩铜矿床的成矿作用是在印支期完成的。主矿体钾长石K-Ar年龄显示热液活动持续到(182.5±1.8)Ma左右,说明与斑岩铜矿有关的热液系统寿命可达40Ma之久。这种长寿命的热液系统是高品位大规模的斑岩铜矿形成的必要条件之一。
The Pulang porphyry copper deposit has its own particularity in the porphyry copper deposit in China. It is of great significance not only for the study of the basic geology and mineral resources evaluation and prediction of the arc belt of Zhongdian Island. However, the porphyry copper deposit has no exact chronological data. Through the determination of the Re-Os age of molybdenite and the K-Ar age of single mineral, the activity time of potash-silicified biotite-quartz porphyry in the Pulang porphyry copper deposit was first determined as ( 235.4 ± 2.4) Ma ~ (221.5 ± 2.0) Ma. The Re-Os age of molybdenite in the quartz-molybdenite stage is approximately (213 ± 3.8) Ma, which are similar to each other. It shows that the mineralization of the Pulang porphyry copper deposit was completed in the Indosinian. The K-Ar ages of main feldspar kyanites show that the hydrothermal activity lasts to (182.5 ± 1.8) Ma, indicating that the hydrothermal system related to porphyry copper deposits can reach a lifetime of 40Ma. This long-lived hydrothermal system is one of the necessary conditions for the formation of high-grade, large-scale porphyry copper deposits.