The Origin Of Granitic Rocks And Its Implications For The Genesis Of Suyunhe Mo Deposit In West Junggar,Xinjiang

The Suyunhe molybdenum deposit is located in the western section of Barruk,Western Junggar,and is a large-scale porphyry molybdenum deposit discovered in the region in recent years.The main intrusions in the mining area are long granite porphyry,monzogranite,and granodiorite.The No.1 rock and No.III rock are mainly peraluminous high-K calc-alkaline granites.Rock genetic analysis shows that it is between type I and S granites.The main body of the rock body is molybdenum mineralization,and the No.II rock body is a dissimilar I-type granite,belonging to the weakly peraluminous high-K calcalkaline granite.The zircon U-Pb ages of the I,II,and III rock masses is 295.8±3.1 Ma,293.3±6.4 Ma,and 296.9±3.4 Ma,respectively,which formed in the post-collision environment of the Early Permian.The three rock masses in the mining area all show trace elements enriched in Rb,U,La,and Hf,and depleted in Ba,Nb,Sr,P,and Ti.Among them,the negative anomalies of Ba,Sr,P,and Ti appear in the No.2 rock mass.The main elements of the three rock masses have similar trends in the Huck plot,indicating that the three ore-bearing rock masses are the same magmatic continuous evolution products.The crystallization temperature of the rock calculated from the zircon Ti temperature of the Suyun River porphyry molybdenum is: Ti temperature range I is between 707°C and 896°C with an average temperature of 805°C;the Ti temperature of the Tier II rock body is between 657°C and Between 832 °C,the average is 723 °C;III rock zircon Ti temperature between 737 °C to 850 °C,with an average of 809 °C.The conclusions indicate that the three rock masses related to mineralization all have higher crystallization temperature of magma.The crystallizing temperatures of No.I and III rock masses are similar,and the crystallization temperature of No.II rock mass is low.Oxygen fugacity of the rock mass ranged from-4.22 to-23.10,with most of the data concentrated between-10 and-20 with an average of-11.68.The zircon ? Ce ratio of the No.II rock mass was 10.33-89.79 with an average of 34.47.The oxygen fugacity ranged from-1.67 to-9.43 with an average value of-11.02.Most of the data were concentrated between-10 and 15,and the ratio of zircon ?Ce in the III rock mass was 2.96-127.32 with an average of 51.37.Degrees range from-0.13 to-23.40 with an average of-8.5.It shows that the ore body is formed in the oxygen fugacity environment in the higher source area.All three rock masses show low 87Sr/86 Sr and high ?Nd(t)and younger Nd model ages.The main intrusions combined with the Suyun River deposit have similarly high ?Hf(t)values and a young age of the second-order model,falling on and near the depleted mantle in the Hf-age diagram.The three granites associated with metallogenesis in the Suyunhe Molybdenum deposit should be remelted by the Neogene lower crust instead of the ancient crust.The Suyunhe molybdenum ore-bearing rock mass is formed in a high-source oxygen fugacity environment and is similar to other large-ultra-large porphyry deposits in the Central Asia orogenic belt,showing that a high oxygen fugacity environment may be conducive to large-scale Formation of rock deposits.