Journal of Jilin University(Earth Science Edition) ›› 2020, Vol. 50 ›› Issue (5): 1387-1403.doi: 10.13278/j.cnki.jjuese.20190301

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Characteristics of Gold-Bearing Minerals and Compositions of In-Situ Sulfur of Laojinchang Gold Deposit in Beishan, Gansu Province and Its Ore-Forming Implications

Huang Shiting1,2,3, Yu Xiaofei1, Lü Zhicheng1, Liu Jiajun2, Li Yongsheng1, Du Zezhong1, Lü Xin1, Sun Hairui1, Du Yilun1   

  1. 1. Development and Research Center, China Geological Survey/Mineral Exploration Technical Guidance Center, Ministry of Natural Resources, Beijing 100037, China;
    2. School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China;
    3. Jiangxi Copper Technology Research Institute Co., Ltd, Nanchang 330096, China
  • Received:2019-12-23 Online:2020-09-26 Published:2020-09-29
  • Supported by:
    Supported by Project of China Geological Survey (DD20160050, DD20190159)

Abstract: Laojinchang gold deposit is one of the most representative medium-sized magmatic hydrothermal gold deposits formed at medium-low temperature in the southern Beishan metallogenic belt. Based on the cross cutting relationships of the different auriferous veins, mineral paragenesis, ore texture and structure, its mineralization stages can be divided into quartz-pyrite stage(Ⅰ), quartz-arsenian pyrite-arsenopyrite stage(Ⅱ), quartz-pyrite-polysulfide stage(Ⅲ), and quartz-calcite stage(Ⅳ). In this paper, the element concentration and composition in the gold-bearing minerals of different ore-forming stages were analyzed by using the electron microprobe analyzer (EMPA). The pyrite of stage I is primarily coarse-grained (0.50-1.50 mm) euhedral cube, with low content of As, Au, and a small amount of fine-grained anhedral asenopyrite. The arsenian pyrites of stage II are surrounded by a large number of arsenopyrites, and the arsenian pyrites are dominantly cubic and pentagonal dodecahedron, rich in As and Au with particle size of 0.30-1.00 mm. Stage II is the most intensive period of mineralization, and the main formation period of arsenopyrites. The arsenopyrites in this stage are primarily appeared as rhombic-columnar, columnar, and radiate-columnar aggregates, rich in S but depleted of As. The pyrites in stage Ⅲ commonly occur as veins of pyrite-chalcopyrite-sphalerite mineral paragenesis, appeared as long strip, with high content of S, Cu, Zn, Au but low content of Fe and As. The mineralization in stage Ⅳ is relatively weak with a small amount of fine-grained anhedral pyrites and asenopyrites. The δ34SV-CDT values of pyrite or and asenopyrite range from -3.8‰ to -2.9‰ (average -3.3‰) in stage Ⅰ, the δ34SV-CDT values of pyrite and asenopyrite range from -4.7‰ to 2.6‰ (average -3.3‰) in stage Ⅱ, and the δ34SV-CDT values of pyrite and sphalerite range from -1.9‰ to 1.0‰ (average 0.1‰) in stage Ⅲ; which suggests a mantle-derived magmatic sulfur provenance, and contaminated by sedimentary sulfur at the late stage, as indicated by in-situ sulfur isotope compositions. Based on the previous study, it is proposed that the ore-forming fluid was evolved from S-rich and As-poor fluids to As-rich and S-poor fluids during the mineralization. In stage Ⅰ, the ore-forming system was in neutral and stable environment with abundant sulfur. In the main stage(II), the ore forming fluid was rich in As, poor in S,and high in oxygen fugacity, and the As-rich fluids was injected into hydrothermal system due to the leaching-infiltration of meteoric water, which led to the formation of the Au-As complexes, and the possible precipitation and accumulation in appropriate place. The ore forming system was characterized by variety of metallogenic elements, rich in S, poor in As, and weak reduction in stage Ⅲ, and Au might enter the pyrite lattice in the form of [Au(HS)2]- or [AuS]- complexes.

Key words: ore-forming stage, gold-bearing mineral, EPMA, sulfur isotope, Laojinchang gold deposit, Beishan orogenic belt

CLC Number: 

  • P618.51
[1] 张洲远. 甘肃北山花牛山金矿地质特征和成矿类型研究[D]. 西安:长安大学, 2016. Zhang Zhouyuan. Geological Characteristics and Metallogenic Type Research of Huaniushan Gold Deposit in Beishan Area Gansu province[D]. Xi'an:Chang'an University, 2016.
[2] 崔惠文, 陈祖伊. 甘肃北山地区金矿地质[M]. 北京:地质出版社, 1996. Cui Huiwen, Chen Zuyi.Geology of Gold Deposit in Beishan Area, Gansu[M]. Beijing:Geological Publishing House, 1996.
[3] 司雪峰, 张华, 张树宏. 甘肃新老金厂金矿床地质特征[J]. 桂林理工大学学报, 2000, 20(3):238-242. Si Xuefeng, Zhang Hua, Zhang Shuhong. The Geological Characters of Xinjinchang and Laojinchang Gold Deposits[J]. Journal of Guilin Institute of Technology, 2000, 20(3):238-242.
[4] 刘伟, 潘小菲. 新疆-甘肃北山金矿南带的成矿流体演化和成矿机制[J]. 岩石学报, 2006, 22(1):171-188. Liu Wei, Pan Xiaofei. Evolution of Ore-Forming Fluids and Formational Mechanism for Gold Deposits in the Southern Beishan,Xinjiang-Gansu Border Area of China[J]. Acta Petrologica Sinica, 2006, 22(1):171-188.
[5] 胡朋. 北山南带构造岩浆演化与金的成矿作用[D]. 北京:中国地质科学院, 2007. Hu Peng. Tectono-Magmatic Evolution and Gold Metallogenesis of the South Beishan Mountain Area[D]. Beijing:Chinese Academy of Geologecal Sciences, 2007.
[6] 朱江. 北山造山带南带构造-岩浆建造与金多金属成矿[D]. 武汉:中国地质大学(武汉), 2013. Zhu Jiang.Tectono-Magmatic Formation and Gold-Polymetallic Mineralization in South Beishan Area, NW China[D]. Wuhan:China University of Geosciences (Wuhan), 2013.
[7] 苗来成, 朱明帅, 张福勤. 北山地区中生代岩浆活动与成矿构造背景分析[J]. 中国地质, 2014, 41(4):1190-1204. Miao Laicheng, Zhu Mingshuai, Zhang Fuqin. Tectonic Setting of Mesozoic Magmatism and Associated Metallogenesis in Beishan Area[J]. Chinese Geology, 2014, 41(4):1190-1204.
[8] 左国朝, 何国琦. 北山板块构造及成矿规律[M]. 北京:北京大学出版社, 1990. Zuo Guochao, He Guoqi. Plate Tectonics and Metallogenic Regularities in Beishan Region[M]. Beijing:Peking University Publishing House, 1990.
[9] 刘雪亚, 王荃. 中国西部北山造山带的大地构造及其演化[J]. 地学研究, 1995, 28:37-48. Liu Xueya, Wang Quan. Geotectonics and Its Evolution of the Beishan Orogenic Belt in the Northwestern China[J]. Geoscience Research, 1995, 28:37-48.
[10] 龚全胜, 刘明强, 梁明宏, 等. 北山造山带大地构造相及构造演化[J]. 西北地质, 2003, 36(1):11-17. Gong Quansheng, Liu Mingqiang, Liang Minghong, et al. The Tectonic Facies and Tectonic Evolution of Beishan Orogenic Belt, Gansu[J]. Northwestern Geology, 2003, 36(1):11-17.
[11] Sengör A M C, Natal'In B A, Burtman V S. Evolution of the Altaid Tectonic Collage and Palaeozoic Crustal Growth in Eurasia[J]. Nature, 1993, 364:299-307.
[12] Jahn B M, Wu F Y, Chen B. Granitoids of the Central Asian Orogenic Belt and Continental Growth in the Phanerozoic[J]. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2000, 91(1):181-193.
[13] 龚全胜, 刘明强, 李海林, 等. 甘肃北山造山带类型及基本特征[J]. 西北地质, 2002, 35(3):28-34. Gong Quansheng, Liu Mingqiang, Li Hailin, et al. The Type and Basic Characteristics of Beishan Orogenic Belt, Gansu[J]. Northwestern Geology, 2002, 35(3):28-34.
[14] 何世平, 任秉琛, 姚文光, 等. 甘肃内蒙古北山地区构造单元划分[J]. 西北地质, 2002, 35(4):30-40. He Shiping, Ren Bingchen, Yao Wenguang, et al. The Division of Tectonic Units of Beishan Area, Gansu-Inner Mongolia[J]. Northwestern Geology, 2002, 35(4):30-40.
[15] Cleven N, Lin S, Guilmette C, et al. Petrogenesis and Implications for Tectonic Setting of Cambrian Suprasubduction-Zone Ophiolitic Rocks in the Central Beishan Orogenic Collage, Northwest China[J]. Journal of Asian Earth Sciences, 2015, 113(1):369-390.
[16] Chen S, Guo Z, Qi J, et al. Early Permian Volcano-Sedimentary Successions, Beishan, NW China:Peperites Demonstrate an Evolving Rift Basin[J]. Journal of Volcanology and Geothermal Research, 2016, 309:31-44.
[17] Guo Q Q, Chung S L, Xiao W J, et al. Petrogenesis and Tectonic Implications of Late Devonian Arc Volcanic Rocks in Southern Beishan Orogen, NW China:Geochemical and Nd-Sr-Hf Isotopic Constraints[J]. Lithos, 2017, 278/279/280/281:84-96.
[18] 李增达. 甘肃花牛山铅锌银多金属矿田岩浆成矿作用与找矿[D]. 北京:中国地质大学(北京), 2018. Li Zengda. Magmatic Mineralization and Prospecting of the Huaniushan Lead-Zinc-Silver Polymetallic Ore Field in Gansu Province, China[D]. China University of Geosciences (Beijing), 2018.
[19] 江永宏, 李胜荣. 湘黔地区下寒武统黑色岩系中镍-钼矿床黄铁矿的成因[J]. 地质通报, 2010, 29(2/3):427-435. Jiang Yonghong, Li Shengrong. The Genesis of Pyrite from Ni-Mo Deposit in the Lower Cambrian Black Rock Series of Hunan and Guizhou Provinces, China[J]. Geological Bulletin of China, 2010, 29(2/3):427-435.
[20] 代军治, 高菊生, 钱壮志, 等. 小秦岭镰子沟金矿床地质特征、黄铁矿原位硫同位素组成及成因意义[J]. 吉林大学学报(地球科学版), 2018, 48(6):1669-1682. Dai Junzhi, Gao Jusheng, Qian Zhuangzhi, et al. Geological Characteristics and S Isotopic Compositions of Pyrite from Lianzigou Gold Deposit in Xiaoqinling Area, and It's Genetic Significance[J]. Journal of Jilin University (Earth Science Edition), 2018, 48(6):1669-1682.
[21] 陈光远, 孙岱生, 张立, 等. 黄铁矿成因形态学[J]. 现代地质, 1987, 1(1):60-74. Chen Guangyuan, Sun Daisheng, Zhang Li, et al. Morphogenesis of Pyrite[J]. Geoscience, 1987, 1(1):60-74.
[22] 赵凯, 杨立强, 李坡, 等. 滇西老王寨金矿床黄铁矿形貌特征与化学组成[J]. 岩石学报, 2013, 29(11):3937-3948. Zhao Kai, Yang Liqiang, Li Po, et al.Morphology and Chemistry Composition of Pyrite in the Laowangzhai Gold Deposit, Ailaoshan Orogenic Belt, SW China[J]. Acta Petrologica Sinica, 2013, 29(11):3937-3948.
[23] Eckert T, Barnes A, Dhawan V, et al. A Revaluation of the Co/Ni Ratio in Pyrite as Geochemical Tool in Ore Genesis Problems[J]. Mineralium Deposita, 1979, 14(3):353-374.
[24] Fleischer M. Minor Elements in Some Sulfide Minerals[J]. Economic Geology, 1955, 50:970-1024.
[25] Wen B J, Fan H R, Hu F F, et al. Fluid Evolution and Ore Genesis of the Giant Sanshandao Gold Deposit, Jiaodong Gold Province, China:Constrains from Geology, Fluid Inclusions and H-O-S-He-Ar Isotopic Compositions[J]. Journal of Geochemical Exploration, 2016, 171:96-112.
[26] Sibson R H, Robert F, Poulsen K H. High-Angle Reverse Faults, Fluid-Pressure Cycling, and Mesothermal Gold-Quartz Deposits[J]. Geology, 1988, 16(6):551-555.
[27] Wilkinson J J, Johnston J D. Pressure Fluctuations, Phase Separation, and Gold Precipitation During Seismic Fracture Propagation[J]. Geology, 1996, 24:395-398.
[28] Peterson E C, Mavrogenes J A. Linking High-Grade Gold Mineralization to Earthquake-Induced Fault-Valve Processes in the Porgera Gold Deposit, Papua New Guinea[J]. Geology, 2014, 42(5):383-386.
[29] Taylor H P. The Oxygen Isotope Geochemistry of Igneous Rocks[J]. Contributions to Mineralogy and Petrology, 1968, 19(1):1-71.
[30] Barnett D E, Chamberlain C P. Relative Scales of Thermal-and Fluid Infiltration-Driven Metamorphism in Fold Nappes, New England, USA[J]. American Mineralogist, 1991, 76(5):713-727.
[31] Morse J W, Luther G W I. Chemical Influences on Trace Metal-Sulfide Interactions in Anoxic Sediments[J]. Geochimica et Cosmochimica Acta, 1999, 63(19):3373-3378.
[32] Scholz F, Neumann T. Trace Element Diagenesis in Pyrite-Rich Sediments of the Achterwasser Lagoon, SW Baltic Sea[J]. Marine Chemistry, 2007, 107(4):516-532.
[33] Mandal B K, Suzuki K T. Arsenic Round the World:A Review[J]. Talanta, 2002, 58(1):201-235.
[34] Simon G, Huang H, Penner-Hahn J E, et al. Oxidation State of Gold and Arsenic in Gold-Bearing Arsenian Pyrite[J]. American Mineralogist, 1999, 84(7/8):1071-1079.
[35] Chen J H, Li Y Q, Zhong S P, et al. DFT Simulation of the Occurrences and Correlation of Gold and Arsenic in Pyrite[J]. American Mineralogist, 2013, 98(10):1765-1771.
[36] Feng K, Fan H R, Hu F F, et al. Involvement of Anomalously As-Au-Rich Fluids in the Mineralization of the Heilan'gou Gold Deposit, Jiaodong, China:Evidence from Trace Element Mapping and In-Situ Sulfur Isotope Composition[J]. Journal of Asian Earth Sciences, 2017, 160:304-321.
[37] Reich M, Kesler S E, Utsunomiya S, et al. Solubility of Gold in Arsenian Pyrite[J]. Geochimica et Cosmochimica Acta, 2005, 69(11):2781-2796.
[38] Seward T M. Thio Complexes of Gold and the Transport of Gold in Hydrothermal Ore Solutions[J]. Geochimica et Cosmochimica Acta, 1973, 37(3):379-399.
[39] Deditius A P, Reich M, Kesler S E, et al. The Coupled Geochemistry of Au and As in Pyrite from Hydrothermal Ore Deposits[J]. Geochimica et Cosmochimica Acta, 2014, 140:644-670.
[40] 杨荣生, 陈衍景, 谢景林. 甘肃阳山金矿床含砷黄铁矿及毒砂的XPS研究[J]. 岩石学报, 2009, 25(11):2791-2800. Yang Rongsheng, Chen Yanjing, Xie Jinglin. X-Ray Photoelectron Spectroscopic Study on Arsenian Pyrite and Arsenopyrite from the Yangshan Gold Deposit,Gansu Province (North China)[J]. Acta Petrologica Sinica, 2009, 25(11):2791-2800.
[41] 毛世东, 杨荣生, 秦艳, 等. 甘肃阳山金矿田载金矿物特征及金赋存状态研究[J]. 岩石学报, 2009, 25(11):2776-2790. Mao Shidong, Yang Rongsheng, Qin Yan, et al.Characteristics of Gold-Bearing Mineral and Occurrence of Gold in the Yangshan Gold Field, Gansu Province[J]. Acta Petrologica Sinica, 2009, 25(11):2776-2790.
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