豫陕小秦岭脉状金矿床三期流体运移成矿作用
A three stage fluid flow model for Xiaoqinling lode gold metallogenesis in the He''''nan and Shaanxi provinces, central China.
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摘要: 位于豫陕交界处的小秦岭脉状金矿是我国第二大黄金产出集中地。流体包裹体研究表明,脉状金矿床石英及碳酸盐矿物中流体包裹体主要有富CO2包裹体、CO2-H2O包裹体和H2O溶液包裹体等三种类型,各热液阶段形成的脉体内有不同的流体包裹体组合。脉状金矿体的形成经历了三期流体成矿作用,第一期形成乳白色石英大脉,它构成了矿脉的主体,流体的性质为富H2O热液,但无金的成矿;第二期(成矿期)流体为中低盐度CO2-H2O-NaCl热液,它叠加在了石英大脉之上,形成(块状)黄铁矿-浅色石英矿体和(网脉状)多金属硫化物-烟灰色石英矿体,成矿期内热液的温度、压力及流体组成的变化是金沉淀成矿的原因;第三期热液又转成低盐度的富水流体,形成石英-碳酸盐脉体,金矿化微弱。Abstract: The Xiaoqinling lode gold field is located in the boundary of He'nan and Shaanxi provinces in central China. More than 1200 gold-bearing quartz veins have been found in the field and it is the second largest gold concentration region of China. All lode gold deposits possess similar mineral assemblages, deformational state, fluid flow characteristics, ore fluid composition and have comparable P - T conditions. Fluid inclusion studies show that large number fluid inclusions, including CO2-rich inclusions, CO2-H2O inclusions and aqueous inclusions, are hosted in vein quartz and carbonate in various mineralization stages. Three successive crystallisation stages are recorded during the formation of gold-bearing veins. Stage 1 - the development of milky quartz veins that formed main parts of the quartz veins. The fluids were H2O-rich and no clear evidence was found for gold deposition during this stage. Stage 2-intense microfissuring of the earlier quartz vein (Stage 1) infillings occurred, associated with the main episode of gold deposition. Massive pyrite-clear quartz ores and network polymetallic sulfide minerals-grey colour quartz ores formed. The fluids were middle-low salinity CO2-H2O-NaCl type. Changes of temperature, pressure and fluid compositions in ore-forming fluids were main causes for gold deposition. Stage 3 fluids changed to lower salinity H2O-rich type. Quartz-carbonate mineral veins were formed and weak gold mineralization happened.
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Key words:
- Fluid inclusions /
- Ore-forming fluid /
- Mineralization /
- Lode gold deposits /
- Xiaoqinling
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[1] [1]Bakker RJ. 1997. Clathrates: Computer programs to calculate fluid inclusion V-X properties using clathrate melting temperatures. Computers & Geosciences, 3: 1-18
[2] [2]Bodnar RJ. 1993. Revised equation and stable for determining the freezing point depression of H2O-NaCl solutions. Geochimica et Cosmochimica Acta, 57: 683-684
[3] [3]Boiron MC, Cathelineau M, Banks DA et al. 1996. P-T-X conditions of late Hercynian fluid penetration and the origin of granite-hosted gold quartz veins in northwestern Iberia: A multidisciplinary study of fluid inclusions and their chemistry. Geochimica et Cosmochimica Acta, 60(1): 43-57
[4] [4]Bowers TS, Helgeson HC. 1983. Calculation of the thermodynamic and geochemical consequences of nonideal mixing in the system H2O-CO2-NaCl on phase relations in geologic systems: equation of state for H2O-CO2-NaCl fluids at high pressures and temperatures. Geochim et Cosmochim Acta, 47: 1247-1275
[5] [5]Brown PE, Hagemann SG. 1995. MacFlincor and its application to fluids in Archean lode-gold deposits. Geochimica et Cosmochimica Acta, 59: 3943-3952
[6] [6]Brown PE, Lamb WM. 1989. P-V-T properties of fluid in the system CO2-H2O-NaCl: New graphical presentations and implication for fluid inclusion studies. Geochim Cosmochim Acta, 53: 1209-1221
[7] [7]Chen YJ. 1996. Fluidization model for intracontinental collision and its metallogenic significance: theoretical inference and evidences from gold deposits, the eastern Qinling Mountains. Earth Science Frontiers, 3: 282-289 (in Chinese with English Abstract)
[8] [8]Chen Yanjing, Chen Huayong, Liu Yulin et al., 1999. Progress and records in the study of endogenetic mineralization during collisional orogenesis. Chinese Science Bulletin, 44: 1681-1689
[9] [9]Chen Yanjing, Fu Shigu. 1992. Gold Mineralisation in West He\'nan. Beijing: Seismic Publishing House, 130-138, 166-186 (in Chinese with English abstract)
[10] [10]Chen Yanjing, Guo Guangjun, Li Xin. 1998. Metallogenic geodynamic background of gold deposits in Granite-greenstone terrains of North China craton. Science in China series D, 41(2):113-120
[11] [11]Diamond LW. 2001. Review of the systematics of CO2-H2O fluid inclusions. Lithos, 55: 69-99
[12] [12]Fan Hongrui, Xie Yihan and Wang Yinglan. 1992. Characteristics and evolution of metamorphic fluid in Xiong\'ershan area, western He\'nan province. Acta Mineralogica Sinica. 12: 299~308 (in Chinese with English Abstract)
[13] [13]Fan Hongrui, Xie Yihan, Zhao Rui and Wang Yinglan. 2000. Dual origins of Xiaoqinling gold-bearing quartz veins: Fluid inclusion evidences. Chinese Science Bulletin, 45: 537-542(in Chinese)
[14] [14]Hu Shouxi, Lin Qianlong. 1988. The Geology and Metallogeny of the Amalgamation Zone Between Ancient North China Plate and South China Plate. Nanjing: Nanjing University Publishing House, 236-255, 359-441 (in Chinese with English abstract)
[15] [15]Hu Shouxi, Wang Henian, Wang Dezi et al.. 1998. Geology and geochemistry of gold deposits in east China. Beijing: Science Press, 65-76 (in Chinese with English abstract)
[16] [16]Jiang N, Xu JH, Song MX. 1999. Fluid inclusion characteristics of mesothermal gold deposits in the Xiaoqinling district, Shaanxi and Henan Provinces, People\'s Republic of China. Mineralium Deposita, 34: 150-162
[17] [17]Jiang N. 2000. Hydrothermal fluid evolution associated with gold mineralization at the Wenyu Mine, Xiaoqinling District, China. Resource Geology, 50(2): 103-112
[18] [18]Li Shimei, Qu Lunquan, Su Zhenbang et al.. 1996. The Geology and Metallogenic Prediction of the Gold Deposit in Xiaoqinling. Beijing: Geological Publishing House. 1-250 (in Chinese with English abstract)
[19] [19]Mao JW, Goldfarb RJ, Zhang ZW et al. 2002. Gold deposits in the Xiaoqinling Xiong\'ershan region, Qinling Mountains, central China. Mineralium Deposita, 37: 306-325
[20] [20]Mikucki EJ. 1998. Hydrothermal transport and depositional processes in Archaean lode-gold system: A review. Ore Geology Review, 13: 307-321
[21] [21]Roedder E. 1984. Fluid inclusions. Rev Mineral, 12: 1-644
[22] [22]van den Kerkhof A. 2001. Carbonic inclusions. Lithos, 55: 49-68
[23] [23]Schwartz MO. 1989. Determining phase volumes of mixed CO2-H2O inclusions using microthermometric measurements. Mineral. Deposita, 24: 43-47
[24] [24]Shepherd TJ, Rankin AH, Alderton DHM. 1985. A practical guide to fluid inclusion studies. Blackie & Son Ltd., 1-239
[25] [25]Thi ry R, van der Kerkhof AM, Dubessy F. 1994. VX properties of CH4-CO2 and CO2-N2 fluid inclusions: modeling for T<31 C and P<400 bar. European Journal of Mineralogy, 6: 753-771
[26] [26]Xie Yihan and Fan Hongrui. 2000. Constrains of high-saline metamorphic fluids to gold deposits in greenstone belts of China. Acta Petrologica Sinica, 16(4): 661-664 (in Chinese with English abstract)
[27] [27]Xie Yihan, Fan Hongrui, Wang Yinglan. 1998. CO2 Fluids and Gold Deposit Formation-related Granite in Xiaoqingling area. Acta Petrologica Sinica, 14(4): 542-548 (in Chinese with English abstract)
[28] [28]Xu Jiuhua, Xie Yuling, Shen Shiliang. 1997. Comparison of ore-forming fluids in Xiaoqinling and Jiaodong gold deposits. Mineral Deposits. 16(2): 151-162 (in Chinese with English abstract)
[29] [29]Zhou Zuoxia, Li Binglun, Guo Kanghen et al. 1993. Genesis of the gold (molybdenum) deposits in southern margin of the northern China Platform. Beijing: Geological Publishing House. 148-246 (in Chinese with English abstract)
[30] 陈衍景. 1996. 陆内碰撞体制的流体作用模式及与成矿的关系-理论推导和东秦岭金矿床的研究成果. 地学前缘, 3(3-4): 282-289
[31] [31]陈衍景, 陈华勇, 刘玉琳等. 1999. 碰撞造山过程中内生矿床成矿作用研究的历史和进展. 科学通报, 44: 1681-1689
[32] [32]陈衍景, 富士谷. 1992. 豫西金矿成矿规律. 北京: 地震出版社, 130-138, 166-186
[33] [33]陈衍景, 郭光军, 李欣. 1998. 华北克拉通花岗绿岩地体中新生代金矿床成矿地球动力学背景. 中国科学(D辑), 28(1): 35-40
[34] [34]范宏瑞, 谢奕汉, 王英兰. 1992. 豫西熊耳山地区变质流体的性质与演化. 矿物学报, 12(4): 299-308
[35] 范宏瑞, 谢奕汉, 赵瑞等. 2000. 小秦岭地区含金石英脉复式成因的流体包裹体证据. 科学通报, 45(5): 537-542
[36] [36]胡受奚, 林潜龙. 1988. 华北与华南古板块拼合带地质与成矿. 南京: 南京大学出版社, 236-255, 359-441
[37] [37]胡受奚, 王鹤年, 王德滋等. 1998. 中国东部金矿地质学及地球化学. 北京: 科学出版社, 65-93
[38] [38]黎世美, 瞿伦全, 苏振邦等. 1996. 小秦岭金矿地质和成矿预测. 北京: 地质出版社, 1-250
[39] [39]谢奕汉, 范宏瑞. 2000. 高盐变质流体对我国绿岩带金矿的制约. 岩石学报, 16(4): 661-664
[40] 谢奕汉, 范宏瑞, 王英兰. 1998. 小秦岭地区花岗岩中CO2-H2O包裹体的找矿意义. 岩石学报, 14(4): 542-548
[41] [41]徐九华, 谢玉玲, 申世亮. 1997. 小秦岭与胶东金矿床的成矿流体特征对比. 矿床地质, 16(2): 151-162
[42] [42]周作侠, 李秉伦, 郭抗衡等. 1993. 华北地台南缘金(钼)矿床成因. 北京: 地震出版社, 76-113
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