Abstract:

The forming age of the Meizikeng molybdenum deposits located in Jiuling-Zhanggongshan ploymetallic metallogenic belt, northern Jiangxi Province, has been determined by the Re-Os isotopic dating method in this paper. The Re-Os dating of 5 molybdenite samples yielded average model ages from 148.2 to 150.7 Ma, with a weighted average of (150±1) Ma, and an isochron age of (148.9±4.4) Ma. Evidently, we can constrain the forming age of Meizikeng deposits at ca.150 Ma. The geological characteristics of the deposit show that the molybdenum mineralization in this deposit is closely related to the Late Jurassic magmatic activities, which accounted for the constant pressure triggered by the simultaneous subduction of the Pacific plate. The forming ages of some deposits in the metallogenic belt allows further inference about the existence of different mineralization processes. The molybdenum polymetallic mineralization was caused by the extension and reduction of the lithosphere (135 Ma±). Moreover, the Late Jurassic mineralization was also found in this metallogenic belt, which was formed by the convergence of lithosphere plate in East Asia since the Late Middle Jurassic period (150 Ma±).The accurate ore-forming age will contribute to mineral exploration in Jiuling-Zhanggongshan polymetallic metallogenic belt, northern Jiangxi Province.

Key words: Re-Os isotopic age, molybdenite, Meizikeng molybdenum deposit, isotope, northern Jiangxi Province