Rhenium-Osmium Isotope Constraints on the Origin of the Tianyu Cu-Ni Deposit in the East Tianshan Orogenic Belt, Xinjiang, NW China  

作　　者：HAN Chunming XIAO Wenjiao AO Songjian ZHANG Jien SONG Dongfang ZHANG Zhiyong SONG Shuaihua XIE Mingcai 

机构地区：[1]Key Laboratory of Mineral Resource,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Xinjiang Research Center for Mineral Resources,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China

出　　处：《Acta Geologica Sinica(English Edition)》2022年第2期525-535,共11页地质学报（英文版）

基　　金：financially supported by funds of the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0801);the National Key R&D Program of China(Grant Nos.2021YFC2901704)。

摘　　要：The Tianyu Cu-Ni sulfide deposit occurs in the north margin of the Central Tianshan Arc in East Tianshan orogenic belt, Xinjiang, NW China. The intrusions consist of gabbro, peridotite, and olivine pyroxenite. The peridotite and pyroxenite are the main host rock for the Cu-Ni ores. Rhenium and osmium isotopic analyses of Ni-and Cu-bearing sulfide minerals from the deposit have been used to determine the source of osmium, and by inference, the sources of ore metals. Sulfide ore samples have Os and Re concentrations varying in the ranges 1.85 to 4.58 ppb and 93.56 to 146.00 ppb, respectively. An initial ^(187)Os/^(188)Os ratio ranges from 0.86 to 1.23 for the ores and the γOs values from 592 to 2227. Osmium isotopic data suggest that the Tianyu intrusion and associated Cu-Ni mineralization has derived from crustal-contaminated mantle melts. The intrusions early show island-arc geochemical signatures, which indicate that the Hulu mafic–ultramafic intrusions, along with the Cu-Ni deposit, formed as a result of subduction of oceanic crust in the Early Permian.

关 键 词：rhenium-osmium isotope Cu-Ni deposit Tianyu intrusion East Tianshan orogenic belt XINJIANG 

分 类 号：P618.41[天文地球—矿床学] P618.63[天文地球—地质学]