红旗岭3号含矿岩体地质年龄及其岩石学特征

以1号和7号岩体为代表的红旗岭铜镍硫化物矿床，是兴蒙造山带中典型的岩浆熔离型矿床。矿区内共有30多个镁铁-超镁铁质岩体，3号岩体是其中的含矿岩体，多年来因其地质产状与主要含矿岩体不同被认为形成于燕山期。本次工作对采自不同深度岩心样品中的单矿物角闪石进行⁴⁰Ar/³⁹Ar同位素年代学研究，得到（228.2±3.0 ）Ma的坪年龄和（230.1±7.1）Ma的等时线年龄。该年龄和近年发表的红旗岭1号岩体地质年龄基本一致，说明它们均为早印支期岩浆作用的产物。通过对比分析1号和7号主含矿岩体与3号岩体的岩石地球化学特征发现，无论是稀土元素还是微量元素图解均显示了它们具有相同的配分模式，暗示了这些岩体的同源性特点。

Mineralization Age of the No.3 Ore-bearing Intrusion and Its Petrological Significance in Hongqiling Cu-Ni Sulfide Deposits, Jilin Province

The Hongqiling magmatic Cu-Ni sulfide deposit represented by No.1 and No.7 intrusions belongs to a typical magmatic liquation deposit in Xing’an-Mongolia orogenic belt. More than 30 mafic-ultramafic intrusions have been found in the Hongqiling mining district. The No.3 intrusion, whose geological occurrence were different from those of other ore-bearing rock bodies, was once thought to be formed during the Yanshanian era. The ⁴⁰Ar/³⁹Ar isotopic dating of amphiboles collected from different depths of core samples in No.3 intrusion gave a （228.2±3.0） Ma plateau age and a （230.1±7.1） Ma isochron age. These isotopic ages consist generally with the ages of No. 1 intrusion published before, all being derived from the Early Indosinian magmatism. Geochemical studies of No.1, No.3, and No.7 ore-bearing intrusions also suggest these intrusions were derived from a common source according to their similar curve patterns of REE and trace elements. This opinion could be significant for guiding further exploration of the magmatic Cu-Ni deposits in the area.