Fluid inclusion study of the Baishan porphyry Mo deposit in the eastern Tianshan ore field, Xinjiang Province
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摘要:
白山钼矿位于东天山觉罗塔格成矿带东段，是新疆极具代表性的大型-超大型斑岩钼矿。根据矿物共生组合和脉体穿插关系，脉体发育顺序依次为：早期石英-钾长石脉、石英-钾长石-辉钼矿脉、石英-辉钼矿脉、石英-多金属硫化物脉和晚期石英-碳酸盐-萤石脉。早期石英-钾长石脉中主要发育纯CH4包裹体(PC型)、CH4-H2O型包裹体(C1型) 和水溶液包裹体(W型)，均一温度集中在320~420℃，盐度为1.98%~8.79% NaCleqv；石英-钾长石-辉钼矿脉中发育含子晶包裹体(S型) 和W型包裹体，均一温度集中在260~400℃，盐度为1.49%~8.65% NaCleqv；石英-辉钼矿脉和石英-多金属硫化物脉发育W型、S型和CO2-H2O型包裹体(C2型)，均一温度分别为200~240℃和140~240℃，盐度分别为2.14%~8.10% NaCleqv和0.33%~10.22% NaCleqv，不包括不熔子矿物的贡献；晚期石英-碳酸盐-萤石脉只发育W型包裹体，均一温度和盐度明显下降，分别为100~160℃和0.17%~4.86% NaCleqv。估算的石英-钾长石脉体和石英-多金属硫化物脉形成压力分别为105~221MPa和15~285MPa。成矿流体由高温、富碳质、还原的岩浆流体向低温、低盐度、贫碳质的大气降水热液演化。成矿阶段温度下降，早期流体中的CH4还原HMoO4-的高价钼，从而形成辉钼矿，可能是导致成矿物质沉淀的重要因素。
Abstract:The Baishan Mo deposit in the eastern Tianshan, Xinjiang Province, is a large-giant porphyry deposit discovered in the eastern Jueluotag tectonic belt. According to paragenesis and crosscutting relationship of the stockworks, ore-forming veinlets in order from early to late are the early quartz-potassic feldspar veinlets, quartz-potassic feldspar-molybdenite veinlets, quartz-molybdenite veinlets, quartz-polymetallic sulfide veinlets and the late stage quartz-carbonate-fluorite veinlets. The hydrothermal quartz in the early quartz-potassic feldspar veinlets mainly contain pure CH4 (PC-type), CH4-H2O (C1-type) and NaCl-H2O (W-type); these fluid inclusions mainly homogenize at temperatures of 320℃ to 420℃, and yield salinities of 1.98% to 8.79% NaCleqv. The quartz-potassic feldspar-molybdenite veinlets contain daughter mineral-bearing (S-type) and W-type fluid inclusions, with homogenization temperatures ranging from 260℃ to 400℃ and salinities of 1.49% to 8.65% NaCleqv. The quartz-molybdenite veinlets and quartz-polymetallic sulfide veinlets contain W-, S-and C2 (CO2-H2O) types of fluid inclusions that are generally homogenized at temperatures of 200℃ to 240℃ and 140℃ to 240℃, with salinities of 2.14% to 8.10% NaCleqv and 0.33% to 10.22% NaCleqv, respectively. The late-stage quartz-carbonate-fluorite veinlets only contain the W-type fluid inclusions mainly which homogenize at 100℃ to 160℃, yielding salinities of 0.17% to 4.86% NaCleqv. The estimated pressures range from 105~221MPa for the early-stage veinlets to 15~285MPa for the quartz-polymetallic sulfide veinlets. In a word, the ore-forming fluids evolve from high temperature, carbonic and reducing magmatic to low temperature and low salinity meteoric. The decrease of temperature and the reduction of high-valent molybdenum of HMoO4- result in the precipitation of molybdenite.
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Key words:
- Fluid inclusion /
- Porphyry Mo deposit /
- Baishan Mo deposit /
- East Tianshan /
- Continental collision
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图 1
白山钼矿床区域地质图(据邓刚等, 2004修编)
Figure 1.
Regional geological map of the Baishan Mo deposit (modified after Deng et al., 2004)
图 3
白山钼矿床15线勘探剖面图(据新疆地矿局第六地质大队，2011)
Figure 3.
Geological profiles for prospecting line No. 15 of the Baishan Mo deposit
图 5
白山钼矿流体包裹体显微照片
Figure 5.
Photomicrographs of fluid inclusions in the Baishan Mo deposit
图 6
白山钼矿床流体包裹体均一温度、盐度直方图
Figure 6.
Histograms showing homogenization temperatures and salinities of fluid inclusions in Baishan Mo deposit
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Ague JJ and Brimhall GH. 1988. Regional variations in bulk chemistry, mineralogy, and the compositions of mafic and accessory minerals in the batholiths of California. Geological Society of America Bulletin, 100(6): 891-911
Bodnar RJ. 1993. Revised equation and table for determining the freezing point depression of H2O-NaCl solutions. Geochimica et Cosmochimica Acta, 57(3): 683-684
Brown PE. 1989. Flincor: A microcomputer program for the reducrion and investigation of fluid-inclusion data. American Mineralogist, 74: 1390-1393
Charvet J, Shu LS and Charvet SL. 2007. Paleozoic structural and geodynamic evolution of eastern Tianshan (NW China): welding of the Tarim and Junggar plates. Episodes, 30(3): 162-186
Chen YJ and Fu SG. 1992. Gold Mineralization in West Henan. Beijing: Seismological Press, 1-234 (in Chinese with English abstract)
Chen YJ. 2000. Progress in the study of Central Asia-type orogenesis-metallogenesis in Northwest China. Geological Journal of China Universities, 6(1): 17-22 (in Chinese with English abstract)
Chen YJ, Pirajno F and Sui YH. 2004. Isotope geochemistry of the Tieluping silver-lead deposit, Henan, China: A case study of orogenic silver-dominated deposits and related tectonic setting. Mineralium Deposita, 39(5-6): 560-575
Chen YJ, Pirajno F and Qi JP. 2005. Origin of gold metallogeny and sources of ore-forming fluids, Jiaodong province, eastern China. International Geology Review, 47(5): 530-549
Chen YJ, Chen HY, Zaw K, Pirajno F and Zhang ZJ. 2007. Geodynamic settings and tectonic model of skarn gold deposits in China: An overview. Ore Geology Reviews, 31(1-4): 139-169
Chen YJ, Ni P, Fan HR, Pirajno F, Lai Y, Su WC and Zhang H. 2007. Diagnostic fluid inclusions of different types hydrothermal gold deposits. Acta Petrologica Sinica, 23(9): 2085-2108 (in Chinese with English abstract)
Chen YJ and Li N. 2009. Nature of ore-fluids of intracontinental intrusion-related hypothermal deposits and its difference from those in island arcs. Acta Petrologica Sinica, 25(10): 2477-2508 (in Chinese with English abstract)
Chen YJ, Pirajno F, Li N, Guo DS and Lai Y. 2009. Isotope systematics and fluid inclusion studies of the Qiyugou breccia pipe-hosted gold deposit, Qinling Orogen, Henan Province, China: Implications for ore genesis. Ore Geology Reviews, 35(2): 245-261
Chen YJ. 2010. On epizonogenism and genetic classification of hydrothermal deposits. Earth Science Frontiers, 17(2): 27-34 (in Chinese with English abstract)
Chen YJ and Wang Y. 2011. Fluid inclusion study of the Tangjiaping Mo deposit, Dabie Shan, Henan Province: Implications for the nature of porphyry systems of the post-collisional tectonic settings. International Geology Review, 53(5-6): 635-655
Chen YJ, Pirajno F, Wu G, Qi JP and Xiong XL. 2012. Epithermal deposits in North Xinjiang, NW China. International Journal of Earth Science, 101(4): 889-917
Chen YJ. 2013. The development of continental collision metallogeny and its application. Acta Petrologica Sinica, 29(1): 1-17 (in Chinese with English abstract)
Collins PLF. 1979. Gas hydrates in CO2-bearing fluid inclusions and the use of freezing data for estimation of salinity. Economic Geology, 74(6): 1435-1444
Deng G, Wu H and Lu QM. 2004. Geological characteristics and prospecting mark of the Baishan porphyry Mo deposit, East Tianshan. Regional Geology of China, 22(5): 388-402(in Chinese with English abstract)
Fan HR, Zhai MG, Xie HY and Yang JH. 2003. Ore-forming fluids associated with granite-hosted gold mineralization at the Sanshandao deposit, Jiaodong gold province, China. Mineralium Deposita, 38(6): 739-750
Fan HR, Hu FF, Wilde SA, Yang KF and Jin CW. 2011. The Qiyugou gold-bearing breccia pipes, Xiong’ershan region, Central China: Fluid inclusion and stable-isotope evidence for an orgin from magmatic fluids. International Geology Review, 53(1): 25-45
Hu SX, Zhao YY, Sun JG, Ling HF, Ye Y, Lu B, Ji HZ, Xu B, Liu HY and Fang CQ. 2002. Fluids and their sources for gold mineralizations in the north China platform. Journal of Nanjing University (Natural Sciences), 38(3): 381-391 (in Chinese with English abstract)
Li HQ, Wu H, Chen FW, Deng G, Yang HM, Yang ZF, Mei YP and Guo J. 2005. Isotopic chronological evidence for Yanshanian diagenetic mineralization in Baishan rhenium-molybdenum mine, E. Tianshan Mountains. Acta Geologica Sinica, 79(2): 249-255 (in Chinese with English abstract)
Li HQ, Chen FW, Li JY, Qu WJ, Wang DH, Wu H, Deng G and Mei YP. 2006. Age of mineralization and host rocks in the Baishan rhenium-molybdenum district, East Tianshan, Xinjiang, China: Revisited. Geological Bulletin of China, 25(8): 916-922 (in Chinese with English abstract)
Li N, Carranza EJM, Ni ZY and Guo DS. 2012a. The CO2-rich magmatic-hydrothermal fluid of the Qiyugou breccia pipe, Henan Province, China: Implication for breccia genesis and gold mineralization. Geochemistry: Exploration, Environment, Analysis, 12(2): 147-160
Li N, Chen YJ, Ulrich T and Lai Y. 2012b. Fluid inclusion study of the Wunugetu Cu-Mo deposit, Inner Mongolia, China. Mineralium Deposita, 47(5): 467-482
Li N, Ulrich T, Chen YJ, Thomsen TB, Pease V and Pirajno F. 2012c. Fluid evolution of the Yuchiling porphyry Mo deposit, East Qinling, China. Ore Geology Reviews, 48: 442-459
Nie FJ, Jiang SH, Zhao XM and Bai DM. 2001. The discovery of two new precious metal deposits in the Inner Mongolia-Gansu-Xinjiang Juncture (Beishan) area and its geological significance. Acta Geoscientia Sinica, 22(5): 388-402 (in Chinese with English abstract)
Pirajno F. 2009. Hydrothermal Processes and Mineral Systems. Berlin: Springer, 1-1250
Pirajno F. 2013. The Geology and Tectonic Settings of China’s Mineral Deposits. Berlin: Springer
Pokrovski GS, Borisova AY, Roux J, Hazemann JL, Petdang A, Tella M and Testemale D. 2006. Antimony speciation in saline hydrothermal fluids: Acombined X-ray sbsorption fine structure spectroscopy and solubility study. Geochimica et Cosmochimica Acta 70(16): 4196-4214
Qin KZ, Sun S, Li JL, Xian WJ and Hao J. 2002. Division of six tectonic stages of major metallic deposits in Northern Xinjiang and its implications. Mineral Deposits, 21(Suppl.2): 203-206 (in Chinese)
Rowins SM. 1999. Reduced porphyry copper-gold deposits: A newly recognized style of gold mineralization. Geological Society of America, 31: A-92
Rowins SM. 2000. Reduced porphyry copper-gold deposits: A new variation on an old theme. Geology, 28(6): 491-494
Schmidt C, Thomas R and Heinrich W. 2005. Boron speciation in aqueous fluids at 22 to 600℃ and 0.1MPa to 2GPa. Geochimica et Cosmochimica Acta, 69(2): 275-281
Shen P, Shen YC, Wang JB, Zhu HP, Wang LJ and Meng L. 2010. Methane-rich fluid evolution of the Baogutu porphyry Cu-Mo-Au deposit, Xinjiang, NW China. Chemical Geology, 275(1-2): 78-98
Testemale D, Hazemann JL, Pokrovski GS, Joly Y, Roux J, Argoud R and Geaymond O. 2004. Structural and electronic evolution of the As(OH)3 molecule in high temperature aqueous solutions: An X-ray absorption investigation. Journal of Chemical Physics, 121(18): 8973-8982
Wang JB and Xu X. 2006. Post-collisional tectonic evolution and metallogenesis in northern Xinjiang, China. Acta Geologica Sinica, 80(1): 23-31 (in Chinese with English abstract)
Xiao WJ, Windley BF, Hao J and Zhai MG. 2003. Accretion leading to collision and the Permain Solonker suture, Inner Mongolia, China: Termination of the central Asian orogenic belt. Tectonics, 22(6): 1069-1089
Xiao WJ, Zhang LC, Qin KJ, Sun S and Li JL. 2004. Paleozoic accretionary and collisional tectonics of the eastern Tianshan (China): Implications for the continental growth of Central Asia. American Journal of Science, 304(4): 370-395
Xiao WJ, Han CM, Yuan C, Chen HL, Sun M, Lin TF, Li ZL, Mao QG, Zhang JE, Sun S and Li JL. 2006. Unique Carboniferous-Permian tectonic-metallogenic framework of northern Xinjiang (NW China): Constrains for the tectonics of the southern Paleoasian Domain. Acta Petrologica Sinica, 22(5): 1062-1076 (In Chinese with English abstract)
Xiao WJ, Han CM, Yuan C, Sun M, Lin SF, Chen HL, Li ZL, Li JL and Sun S. 2008. Middle Cambrian to Permian subduction-related accretionary orogenesis of northern Xinjiang, NW China: Implications for the tectonic evolution of central Asia. Journal of Asian Earth Sciences, 32(2-4): 102-117
Xiao WJ, Shu LS, Gao J, Xiong XL, Wang JB, Guo ZJ, Li JY and Sun M. 2008. Continental dynamics of the Central Asian orogenic belt and its metallogeny. Xinjiang Geology, 26(1): 4-8(In Chinese with English abstract)
Xiao WJ, Windley BF, Huang BC, Han CM, Yuan C, Chen HL, Sun M, Sun S and Li JL. 2009. End-Permian to Mid-Triassic termination of the accretionary processes of the southern Altaids: Inplications for the geodynamic evolution, Phanerozoic continental growth, and metallogeny of Central Asia. International Journal of Earth Sciences, 98(6): 1189-1217
Yang YF, Li N and Chen YJ. 2012. Fluid inclusion study of the Nannihu giant porphyry Mo-W deposit, Henan Province, China: Implications for the nature of porphyry ore-fluid systems formed in a continental collision setting. Ore Geology Reviews, 46: 83-94
Yang YF, Chen YJ, Li N, Mi M, Xu YL, Li FL and Wan SQ. 2013. Fluid inclusion and isotope geochemistry of the Qian’echong giant porphyry Mo deposit, Dabie Shan, China: A case of NaCl-poor, CO2-rich fluid systems. Journal of Geochemical Exploration, 124: 1-13
Zhai YS, Yao SZ and Cai KQ. 2011. Mineral Deposits. 3rd Edition. Beijing: Geological Publishing House (in Chinese)
Zhang DY, Zhou TF, Yuan F, Fan Y, Liu S and Qu WJ. 2009. A genetic analysis of Baishan molybdenum deposit in East Tianshan area, Xinjiang. Mineral Deposits, 28(5): 663-672 (in Chinese with English abstract)
Zhang LC, Xiao WJ, Qin KZ, Qu WJ and Du AD. 2005. Re-Os isotopic dating of molybdenite and pyrite in the Baishan Mo-Re deposit, eastern Tianshan, NW China, and its geological significance. Mineralium Deposita, 39(8): 960-969
Zhou TF, Yuan F, Zhang DY, Fan Y, Liu S, Peng MX and Zhang JD. 2010. Geochronology, tectonic setting and mineralization of granitoids in Jueluotage area, eastern Tianshan, Xinjiang. Acta Petrologica Sinica, 26(2): 478-502 (in Chinese with English abstract)
Zotov AV, Shikina ND and Akinfiev NN. 2003. Themogynamic properties of the Sb(III) hydroxide complex Sb(OH)3(aq) at hydrothermal conditions. Geochimica et Cosmochimica Acta, 67(10): 1821-1836
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