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Hao Y.-J.,Jilin University | Ren Y.-S.,Jilin University | Ren Y.-S.,Key Laboratory of Mineral Resources Evaluation in Northeast Asia | Yang Q.,Jilin University | And 4 more authors.
Resource Geology | Year: 2015

The Gaogangshan Mo deposit, located in the northern part of the Lesser Xing'an Range (the eastern part of the Xing'an-Mongolia Orogenic Belt), is one of the newly discovered Mo deposits in northeast China. Ore bodies occur in the granite and are generally in vein and stockwork forms. Major metallic minerals in the ore include pyrite and molybdenite. The styles of mineralization are disseminated, veinlet-disseminated, and veinlet. The major types of wall-rock alteration are silicification-potassic alteration, phyllic alteration and propylitization. Fluid inclusion analyses indicate that the ore-forming fluid during the major mineralization stage is an H2O-NaCl-CO2 system, with wide homogenization temperature and salinity ranges. The abundant CO2-rich and coexisting halite-bearing fluid inclusion assemblages in the main stage of mineralization highlight the significance of intensive fluid boiling for porphyry Mo mineralization. Comprehensive study of the ore-forming conditions, geological features of the deposit, micro-thermometric analysis of fluid inclusions and comparison of the Gaogangshan deposit with other typical porphyry deposits leads to the conclusion that the deposit is a porphyry type. We obtained a weighted mean age of the molybdenite deposit at Gaogangshan of 250.7±1.8 Ma. The isotopic dating results indicate that the Gaogangshan deposit was formed in the Permo-Triassic, which is the earliest Mo-only deposit in northeast China. The formation of the Gaogangshan Mo deposit may be related to the extension and break-up of the Songnen Block and Jiamusi Block in the Permo-Triassic. © 2015 The Society of Resource Geology. Source

Chen C.,Jilin University | Ren Y.-S.,Jilin University | Ren Y.-S.,Key Laboratory of Mineral Resources Evaluation in Northeast Asia | Zhao H.-L.,Jilin University | And 3 more authors.
International Geology Review | Year: 2014

The Wudaogou Group in eastern Yanbian, Northeast China, plays a key role in constraining the timing and eastward termination of the Solonker-Xra Moron River-Changchun Suture, where the Palaeo-Asian Ocean closed. The Wudaogou Group consists of schist, gneiss, amphibolite, metasedimentary, and metavolcanic rocks, all of which underwent greenschist- to epidote-amphibolite-facies regional metamorphism, with some hornfels resulting from contact metamorphism. To determine the age of deposition, the timing and grade of metamorphism, and the tectonic setting of the Wudaogou Group, we investigated the petrography and geochronology of the metamorphic rocks in this group. Zircons from the metasedimentary rocks of this group can be divided into metamorphic zircons and detrital zircons of magmatic origin. U-Pb ages of metamorphic zircons dated by LA-ICP-MS vary from 249 ± 4 to 266 ± 4 Ma, approximating the age of regional metamorphism in the eastern Yanbian area. Detrital zircons yield U-Pb ages ranging from 253 ± 5 to 818 ± 5 Ma, and indicate that the provenance of the Wudaogou Group experienced four tectonic-thermal events between 818 and 253 Ma: Neoproterozoic (ca. 818-580 Ma), Cambro-Ordovician (ca. 500-489 Ma), Devonian-Carboniferous (ca. 422-300 Ma), and middle-late Permian (ca. 269-253 Ma). The youngest detrital zircon, with a U-Pb age of 253 ± 5 Ma, defines the maximum depositional age of the Wudaogou Group. The presence of the Cambro-Ordovician and Neoproterozoic detrital zircons implies that the source of the Wudaogou Group had an affinity with Northeast China, which leads us to conclude that the Solonker-Xra Moron River-Changchun Suture extends from Wangqing to Hunchun in eastern Yanbian, and that the Palaeo-Asian Ocean may have closed at the end of the Permian or Early Triassic period. © 2014 Taylor & Francis. Source

Chen C.,Jilin University | Ren Y.,Jilin University | Ren Y.,Key Laboratory of Mineral Resources Evaluation in Northeast Asia | Zhao H.,Tianjin Institute of Geology and Mineral Resources | And 2 more authors.
Resource Geology | Year: 2015

The late Paleozoic Wudaogou Group, one of the oldest metamorphic units in the eastern Yanbian area, has important tectonic and metallogenic significance. Here, we provide new insights into their protoliths, tectonic setting of the metamorphic rocks and their relationships with the gold and tungsten mineralization, using new petrographic and whole-rock geochemical data for various lithologies within the Wudaogou Group. The protolith of the metamorphic rocks of the Wudaogou Group was intermediate-basic volcanic rocks (e.g. basaltic andesite, trachyandesite, and basalt) and sedimentary rocks including argillaceous rocks, quartz sandstone, arkose and clayish greywacke, as well as pyroclastic sedimentary rock, covering tuffaceous sandstone. Before undergoing late Paleozoic epidote-amphibolite facies regional metamorphism, these protoliths were formed during the middle-late Permian in an island arc setting within a continental margin collage zone. Combined with the regional tectonic evolution, it can be speculated that the formation and the subsequent metamorphism of the protoliths of the metamorphic rocks from the Wudaogou Group were influenced by the change from subduction to collision of the Paleo-Asian Ocean. Similarities of the rare earth element (REE) patterns and parameters among the metamorphic rocks within the Wudaogou Group, auriferous ores from the Xiaoxi'nancha gold (copper) deposit, and scheelites from the Yangjingou tungsten deposit, together with the favorable metallogenic element contents within the metamorphic rock series, imply that the Wudaogou Group could provide parts of metallic material for the gold and tungsten mineralization in the eastern Yanbian area, as exemplified by the Yangjingou deposit and Xiaoxi'nancha deposit, respectively. Further, the metamorphic sedimentary rocks, especially the metamorphic sandstones, quartz schists and quartz mica schists within the Wudaogou Group, have closer genetic relationships with the Yangjingou tungsten mineralization. However, the specific lithologies within this group which control the gold mineralization are still uncertain, and need further research. © 2015 The Society of Resource Geology. Source

Liu Y.,Jilin University | Liu Y.,Key Laboratory of Mineral Resources Evaluation in Northeast Asia | Liu Y.,Northwest University, China | Li W.,Jilin University | And 8 more authors.
Gondwana Research | Year: 2016

The Central Asian Orogenic Belt (CAOB) is the largest accretionary orogen in the world, which is responsible for considerable Phanerozoic juvenile crustal growth. The NE China and its adjacent areas compose the eastern segment of the CAOB, which is a key area for providing important evidence of the CAOB evolution and understanding the NE Asian tectonics. The eastern segment of the CAOB is composed tectonically of four micro-blocks and four sutures, i.e. Erguna block (EB), Xing'an block (XB), Songliao-Xilinhot block (SXB), Jiamusi block (JB), Xinlin-Xiguitu suture (XXS), Heihe-Hegenshan suture (HHS), Mudanjiang-Yilan suture (MYS) and Solonker-Xar Moron-Changchun-Yanji suture (SXCYS). The EB and XB were amalgamated by westward subduction, oceanic island accretions and final collision in ca. 500. Ma. The XB and SXB were amalgamated by subduction-related Early Paleozoic marginal arc, Late Paleozoic marginal arc and final collision in the late Early Carboniferous to early Late Carboniferous. The JB probably had been attached to the SXB in the Early Paleozoic, but broken apart from the SXB in the Triassic and collided back in the Jurassic. The closure of Paleo-Asian Ocean had experienced a long continue/episodic subduction-accretion processes on margins of the NCC to the south and the SXB to the north from the Early to Late Paleozoic. The final closure happened along the SXCYS, from west Solonker, Sonid Youqi, Kedanshan (Keshenketengqi), Xar Moron River through Songliao Basin via Kailu, Tongliao, Horqin Zuoyizhongqi, Changchun, to the east Panshi, Huadian, Dunhua, Yanji, with a scissors style closure in time from the Late Permian-Early Triassic in the west to the Late Permian-Middle Triassic in the east. The amalgamated blocks should compose a united micro-continent, named as Jiamusi-Mongolia Block (JMB) after Early Carboniferous, which bounded by Mongo-Okhotsk suture to the northwest, Solonker-Xar Moron-Changchun suture to the south and the eastern margin of JB to the east. © 2016 International Association for Gondwana Research. Source

Yang Q.,Jilin University | Ren Y.,Jilin University | Ren Y.,Key Laboratory of Mineral Resources Evaluation in Northeast Asia | Chen C.,Jilin University | And 2 more authors.
Geological Bulletin of China | Year: 2015

The Dongfengbeishan molybdenum deposit is located in northeastern Tianbaoshan ore concentration area in Yanbian Prefecture, Northeast China. Almost all discovered orebodies are controlled by faults and fractures in biotite quartz diorite, and characterized by veins and veinlets. The deposit experienced three metallogenic stages, namely quartz-molybdenite stage, quartz-polymetallic sulfide stage and quartz-calcite stage. Fluid inclusions in ore-bearing quartz veins can be classified into liquid-rich phase, gas-rich phase, daughter mineral-bearing three-phase and minor CO2-bearing three-phase occasional pure CO2 inclusions. Fluid boiling occurred during ore-forming evolution and might have played a very important role in metal elements precipitation. Besides H2O vapor, the gas phase in different types of inclusions, analyzed by Laser Raman Spectrum, also contains small amounts of CO2 and CH4, which indicates that the ore-forming fluid belongs to the H2O-NaCl±CO2±CH4 magmatic fluid system with medium-high temperature and medium-high salinity. The discovered vein molybdenum orebodies in the Dongfengbeishan molybdenum deposit resulted from the porphyry molybdenum mineralization, which implies that the metallogenic porphyry intrusion should have occurred under the biotite quartz diorite. The veinlet disseminated molybdenum mineralization has important guiding implications for further theoretical research and geological prospecting. ©, 2015, Science Press. All right reserved. Source

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