Abstract:

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.

Key words: magmatic Cu-Ni sulfide deposit, Hongqiling Jilin Province, Xing’an-Mongolia orogenic belt, geochronology