Understanding the magmatic-hydrothermal cooling and exhumation history is fundamental for investigating porphyry deposit formation and preservation. In the Zhunuo porphyry copper deposit of southern Tibet, hydrothermal biotite related to early potassic alteration likely formed from 14.7 ± 0.3 Ma (zircon U-Pb age) to 14.23 ± 0.13 Ma (molybdenite Re-Os age) and cooled below the closure temperature for 40Ar/39Ar system at 13.91 ± 0.05 Ma (hydrothermal biotite 40Ar/39Ar plateau age). The 40Ar/39Ar spectra of another hydrothermal biotite sample that was selectively replaced by chlorite record the timing of late phyllic alteration at 13.53 ± 0.08 Ma. Zhunuo hydrothermal alteration and mineralization likely ceased at 13.09 ± 0.07 Ma based on the 40Ar/39Ar plateau age of the fresh magmatic biotite crystals. The biotite 40Ar/39Ar systematics have not been reset by ~ 12.0 Ma post-mineralization granite porphyry within ore district, which is likely due to rapid cooling and/or absence of fluid exsolution for the granite porphyry. In combination with previous zircon U-Pb and molybdenite Re-Os data, two-pulses of magmatic-hydrothermal activity from 14.78 ± 0.11 to 14.44 ± 0.05 Ma and from 14.23 ± 0.13 to 13.53 ± 0.08 Ma can be recognized at Zhunuo. (U-Th)/He thermochronological data on zircon and apatite from the inter-mineralization monzogranite porphyry suggest three cooling events characterized by first-stage magmatic cooling at a rate of ~ 1850 °C/m.y., and two later phases of uplift and exhumation at ~ 70 °C/m.y. and ~ 10 °C/m.y. Approximately 1.4-km thickness of materials have been removed from the Zhunuo Miocene monzogranite porphyry during uplift and erosion, including a large volume of ore.

中文翻译：

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藏南冈底斯带朱诺斑岩铜矿40Ar/39Ar和(U-Th)/He新定年：对脉冲岩浆-热液过程和矿石折返与保存的意义

了解岩浆-热液冷却和折返历史是研究斑岩沉积形成和保存的基础。在藏南朱诺斑岩铜矿床中，与早期钾化蚀变有关的热液黑云母可能形成于 14.7±0.3 Ma（锆石 U-Pb 年龄）至 14.23±0.13 Ma（辉钼矿 Re-Os 年龄）并冷却至闭合温度以下40Ar/39Ar 系统在 13.91 ± 0.05 Ma（热液黑云母 40Ar/39Ar 高原时代）。另一个被绿泥石选择性取代的热液黑云母样品的 40Ar/39Ar 光谱记录了晚叶状体蚀变的时间在 13.53 ± 0.08 Ma。根据新鲜岩浆黑云母晶体的 40Ar/39Ar 高原年龄，朱诺热液蚀变和矿化可能在 13.09±0.07 Ma 停止。黑云母 40Ar/39Ar 系统尚未被矿区内约 12.0 Ma 后矿化花岗岩斑岩重置，这可能是由于花岗岩斑岩的快速冷却和/或缺乏流体出溶。结合先前的锆石 U-Pb 和辉钼矿 Re-Os 数据，在竹奴可以识别出 14.78 ± 0.11 至 14.44 ± 0.05 Ma 和 14.23 ± 0.13 至 13.53 ± 0.08 Ma 的两个岩浆热液活动脉冲。(U-Th)/He 来自矿化间二长花岗岩斑岩的锆石和磷灰石的热年代学数据表明三个冷却事件的特征是第一阶段岩浆冷却的速度约为 1850 °C/my，以及两个后期的隆起和折返阶段在 ~ 70 °C/my 和 ~ 10 °C/my 大约 1.