Abstract

Info

Title:: Zircon U-Pb Dating and Geological Significance of Gneissic Granite in Xinli Gold Deposit of Heilongjiang

Author(s):: ZHANG Lin; YANG Yan-chen; HAN Shi-jiong; BO Jun-wei; WANG Feng-bo; NIE Shi-jia; College of Earth Sciences, Jilin University, Changchun 130061, Jilin, China

Keywords:: gneissic granite; I-type granite; petrogeochemistry; zircon U-Pb age; metallogenic age; Xinli gold deposit; Heilongjiang

Abstract:: Xinli gold deposit in Heilongjiang is located in the center of Jiamusi massif, which belongs to the eastern section of Xing-Meng orogenic belt. The ore bodies are hosted in interstratified fracture belt of Liumao Formation mica-quartzose schist. LA-ICP-MS zircon U-Pb dating of gneissic granite was analyzed, and the geochemistry characteristics of whole rock major and trace elements were reported, and the petrogenesis, formation age and tectonic setting were discussed. The petrogeochemistry shows that gneissic granite is characterized by calc-alkaline and metaluminous-peraluminous rocks, and is enriched in large ion lithophile elements(Rb, K and Ba), and is depleted with different degrees in high field strength elements(U, Ta, Nb, Zr, Ti and Hf); the fractionation of light and heavy rare earth elements is obvious, and heavy rare earth element is depleted, and negative Eu anomaly is weak. LA-ICP-MS zircon U-Pb age of gneissic granite is (266.0±4.7)Ma. The ore-forming fluids are produced in late period during granitic magma evolution, so that the metallogenic age of Xinli gold deposit maybe Late Permian. The gneissic granite belongs to I-type granite, and is formed by the subduction of Paleo-Asian Ocean Plate in Late Paleozoic.