Origin and Geochronology of Chang'anpu Mo-Cu Deposit in Jilin Province: Constraints from Molybdenite Re-Os Isotope Systematics

Abstract

The east-central part of Jilin Province, located on the continental margin of northeast China along the eastern Xing-Meng orogenic belt, hosts more than 10 large-and medium-scale Mo deposits. The major types of mineralization include porphyry, skarn, and quartz vein types. The Chang'anpu Mo-Cu deposit is a newly discovered large-scale porphyry deposit in central Jilin Province; the age of mineralization is unknown. The geological characteristics of the deposit were investigated and molybdenite Re-Os isotope dating was applied, to constrain the age of mineralization. The molybdenite Re-Os model ages range from 167.3±2.4 to 168.7±2.4 Ma with a weighted mean model age of 168.0±1.0 Ma. The isochron age is 168.0±6.2 Ma, which indicates that the Chang'anpu Mo-Cu deposit was formed in the Middle Jurassic, belonging to the large-scale Yanshanian molybdenum metallogenic period of North China. The Re content of the molybdenite varies from 25.17 to 34.80 μg/g, suggesting that the ore-forming materials may come from a crust-mantle mixed source and mainly from the crustal source. Combining published molybdenite Re-Os and zircon U-Pb ages in east-central Jilin Province, suggests that the Mo mineralization occurred in the Early-Middle Jurassic (167-196 Ma), thereby providing a scientific basis for Mo resources prospecting in Jilin.

Keywords

• molybdenite
• re-os isotopic dating
• middle jurassic
• chang'anpu mo-cu deposit
• central jilin province