Abstract

The first data of a U–Pb isotopic study (LA-ICP-MS method) of zircon from leucocratic granites of the giant Tyrnyauz Mo–W deposit (North Caucasus) are presented. The emplacement of this granite separated the formation stages of Mo–W skarns and younger large stockworks with Mo-mineralization. Two types of zircons are distinguished among the grains identified. The first type is represented by rare tabular and short-prismatic crystals (xenocrysts) of an ancient zircon, with large variations of the U–Pb isotopic age (from about 300 Ma to almost 1500 Ma). The second type includes more abundant long-prismatic crystals of a young zircon; its weighted average U–Pb isotopic age (2.67 ± 0.04 Ma) corresponds to the time of leucocratic granite crystallization.

中文翻译：

---

来自 Tyrnyauz Mo-W 矿床（俄罗斯北高加索）的白晶花岗岩的锆石 U-Pb 同位素年龄的第一批数据（LA-ICP-MS 方法）

摘要

展示了来自巨型 Tyrnyauz Mo-W 矿床（北高加索）的白斑花岗岩的锆石 U-Pb 同位素研究（LA-ICP-MS 方法）的第一批数据。这种花岗岩的就位将 Mo-W 矽卡岩的形成阶段和具有 Mo 矿化作用的较年轻的大型网厂分开。在鉴定的晶粒中可以区分两种类型的锆石。第一种类型以古老锆石的稀有板状和短棱柱状晶体（异晶）为代表，U-Pb 同位素年龄变化很大（从约 300 Ma 到近 1500 Ma）。第二种类型包括更丰富的年轻锆石长棱柱晶体；其加权平均 U-Pb 同位素年龄 (2.67 ± 0.04 Ma) 对应于白斑花岗岩结晶的时间。