U-Pb SHRIMP dating of zircons from Duobaoshan granodiorite in Heilongjiang and its geological significance

Abstract

SHRIMP U-Pb dating of zircons from Duobaoshan granodiorite is 479.5±4.6 Ma. According to Re-Os isotopic isochron age(506±14 Ma)for molybdenite in Duobaoshan and Tongshan copper(molybdenum)deposit,as well as the regional geological data,it is considered that the emplacement age of Duobaoshan granodiorite is in pre-Ordovician. Meanwhile,the age of wall rocks,main metallogenic stage,ore-control structures and host structures in Duobaoshan deposit all belong to pre-Ordovician. Duobaoshan granodiorite formed in volcanic arc tectonic setting or active continental margin structural environment,and the magma source mainly came from mantle with partial crustal substance.