安徽省铜山矽卡岩型铜矿床流体成矿作用研究
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摘要
长江中下游是我国东部重要的铁、铜、金多金属成矿带,安徽铜山铜矿位于扬子地块的西北缘,北临大别造山带,是该成矿带安庆~(-)贵池矿集区中的一个典型的矽卡岩型矿床。矿床产于燕山期铜山岩体与石炭系黄龙~(-)船山组、二叠系栖霞组地层的接触带中,受岩浆岩、构造、地层和围岩蚀变的共同控制。NE和EW向断裂构造交汇部位控制成矿岩体的就位,控矿和容矿构造主要为接触带构造及不整合面构造等。成矿过程可分为三个阶段:矽卡岩阶段、石英~(-)硫化物阶段和碳酸盐阶段。
     各成矿阶段的石榴石、石英和方解石中的流体包裹体岩相学研究结果表明,包裹体主要类型有NaCl~(-)H_2O型流体包裹体(W型)、含子矿物流体包裹体(S型)。在石榴石和石英中发现晶质熔融包裹体。矽卡岩阶段的流体包裹体主要为W型和S型,均一温度为478~769℃,盐度为55.47 wt%,成矿流体具有高温、高盐度的特征;石英~(-)硫化物阶段的流体包裹体主要为W型,S型次之,均一温度为86.2~399.5℃,盐度为0.18~22.91wt%,成矿流体具有中低温、中低盐度的特征;碳酸盐阶段的流体包裹体全为W型,均一温度为154.6~368.5℃,盐度为0.53~22.91wt%,成矿流体具有中低温、低盐度的特征。从矽卡岩阶段到石英~(-)硫化物阶段,均一温度和盐度快速降低,从石英~(-)硫化物阶段到碳酸盐阶段均一温度和盐度变化不明显。经估算,铜山铜矿的成矿压力大约为21Mpa,形成深度可能为2.3km。
     流体包裹体主要气体组成为H_2O、CO_2、CH_4,液相离子主要为Ca~(2~(+))、K~(+)、SO4~(2~(-))、Cl~(-)。从矽卡岩阶段到碳酸盐阶段,CO_2、CH_4、Ca~(2~(+))、SO4~(2~(-))、Cl~(-)含量逐渐降低,K~(+)含量逐渐上升,H_2O先减少后增加。
     包裹体的氢氧同位素表明,成矿流体主要来源于岩浆热液,后期有大气降水混入。硫铅同位素表明,成矿物质来源于岩浆;Re~(-)Os同位素定年表明,铜山铜矿的成矿时间是150.98±0.78 Ma,为燕山早期。根据不同类型包裹体共生组合及流体演化特征,认为熔体~(-)流体的不混溶作用和流体的混合作用是金属沉淀的主要原因。
The Tongshan copper deposit in Anqing-Guichi Cu-Fe-Au-Mo district is a typical skarn deposit in The Lower Yangtze River metallogentic belt, which is located at the northern margin of the Yangze craton and bordered by the Dabieshan orogenic belt to the north.
     The ore bodies are related to Tongshan granodiorite and quartz monzonite porphyry, which intruded mainly into Middle Carboniferous Huanglong-Chuanshan Formation, Lower Permian Qixia Formation carbonates and is characterized by porphyritic textures and carbonatization. The location of ore-forming intrusions were controlled by the intersecting places between the NE and EW trending fault structures. The ore-controlling and ore-bearing structures mainly include contact zone, interlayer fractures zone and unconformity structure, etc. The metalogenic processs can be devided into the skarn stage, the quartz-sulfide stage and the carbonate stage. In recent years, new ore layers have been discovered, but the study on fluid inclusions is urgently needed which restricts the ore genesis and metallogenic laws.
     This paper made further discussion on the source of ore-forming materials and the ore genesis in terms of fluid inclusions. Petrographic observations and temperature results indicate that the main types of fluid inclusions are aqueous inclusions, daughter-mineral-bearing multiphase inclusions, occasionally crystalline melt inclusions(recognized in garnet, quartz) which are the evidence of magmatic skarn. In the skarn stage, the ore-forming fluid is characterized by high temperature and high salinity, Th (homogenization temperature) is 478~769℃with salinity of 55.47 wt%. In the quartz-sulfide stage, the ore-forming fluid is characterized by middle-low temperature and middle-low salinity, Th is 86.2~399.5℃with salinity 0.18~22.91wt%; In the carbonate stage, the ore-forming fluid is characterized by middle-low temperature and low salinity, Th ranges from 154.6 to 368.5℃with salinity from 0.53 to 22.91wt%. The Metallogenic pressure is approximately 21Mpa, Metallogenic depth is 2.3km.
     The results of Raman analysis indicate that major components of gaseous or supercritical species are H_2O, CO_2, CH_4; the major ions in solution are Ca~(2+), K~+, SO4~(2-), Cl~-. From early to late stage, the contents of CO_2, CH_4, Ca~(2+), SO4~(2-), Cl~- decreased, K~+ increased, H_2O decreased firstly and then increased.
     The D-O isotopic analysis indicates that the ore-forming fluids were mainly magmatic hydrothermal fluids and mixed with meteoric water during the later mineralization stage; The S and Pb isotopic analysis indicate that metallogenic material derived from magma; the Re-Os dating indicates Metallogenic age is 150.98±0.78 Ma, Early Yanshanian.
     According to the assemblage and evolution characteristics of different fluid inclusions, the immiscibility of melt-fluids and the mixing of fluids are the main causes for mineralization.
引文
Bodnar RJ. Revised and equation and table for determining the freezing point depression of H_2O-NaCl solutions. Geochimica et Cosmochimica Acta, 1993, 57(3): 683~684
    Calagari A A and Hosseinzadeh G. The mineralogy of copper-bearing skarn to the east of the Sungun-Chay river, East-Azarbaid-jan, Iran. Journal of Asian Earth Sciences, 2006, 28: 423~438
    Clayton R N, O'Neil J R,. Mayeda T K. Oxygen isotope exchange between quartz and water. Journal of Geophysical Research, 1972, 77: 3057~3067
    Einaudi M T, Burt D M. Introduction: Terminology, classification and composition of skarn deposit. Economic Geology, 1982, 77(4): 745~760
    Einaudi M T, Meinert L D, Newberry R J. Skarn deposits.Econ Geology, 75 th Anniv, 1981: 317~391
    Hall DL, Sterner SM and Bodnar RJ. Freezing point depression of NaCl-KCl-H_2O solutions. Econ. Geol. 1988, 83: 197~202
    Helgeson HC. Thermodynamics of Hydrothermal systems at elevated and pressures. Am Jour Sci, 1969, 59: 729~804
    Liu L M, Zhao Y L and Zhao X L. Computational modeling oncoupled MTH processes for forming skarn Cu deposits and its signifi-cance for deep ore exploration: Examples from Tongling-Anqing district, China. Journal of Geochemical Exploration, 2009, 101: 63
    Meinert L D. A review of skarn that contain gold. In: LentzD R, ed. Mineralized intrusion- related skarn systems. Quebec. Short Course Series, 1998, 26: 359~414
    Meinert L D. Application of skarn deposit zonation models tomineral exploration. Explor. Mining Geol., 1997a, 6 (2): 185~208
    Meinert L D. Dipple G M and Nicolescu S. World skarn deposits. Econ Geol., 2005, 100: 299~336 Naden J, Shepherd T J. Role of methane and carbon dioxide in good deposition. Nature, 1989, 243: 793~795
    O’Neil J R, Clayton R N and Mayeda T K. Oxygen isotope fractionation in divalent mental carbonates. J. Chem. Phys, 1969, 51: 5547~5558
    Pan Y M, Dong P. The lower Changjiang(Yangzi/Yangtze River)metallogenetic belt, east central China: intrusion-and wall rock-hosted Cu-Fe-Au, Mo, Zn, Pb, Ag deposits. Ore Geology Reviews, 1999, 15(4): 177~242
    Rodder E. Fluid inclusion evidence on the genesis of ores in sedimentary and volcanic rocks// Wolf K H. Handbook of Strata-bound and stratiform Ore Deposits: I. Principles and General Studies: Vol. 2, Geochemical Studies. New York: Elsevier, 1976: 67~110
    Roedder E. The composition of fluid inclusions. U. S. Geological Survey prof. paper 440 JJ,1972,164
    Sun YL, Xu P, Li J et al. A practical method for determination of molybdenite Re-Os ages by inductively coupled plasma-mass spectrometry combined with Carius tube-HNO_3 digestion. The Royal Society of Chemistry: Analytical Methods, 2010, 2: 575~581
    Talor H P. The application of oxygen and hydrogen isotope studies to problems of hydrothermal alteration and ore deposition. Econ. Geol., 1974, 69: 843~883
    Zartman R. E, Doe B. R. Plumbotectonics-the model. Tectonophysics, 1981, 75: 135~162
    Zhou Tao-fa, Yuan Feng, Yue Shu-cang, et al. Geochemistry and evolution of ore-forming fluids of the Yueshan Cu-Au skarn and vein-type deposits, Anhui Province, South China. Ore Geology Reviews, 2005, 31: 279~303
    常印佛,刘湘培,吴言昌.长江中下游铜铁成矿带.北京:地质出版社, 1991: 224~312
    常印佛,刘学圭.关于层控式夕卡岩型矿床,矿床地质, 1983, 2(1): 11~20
    陈衍景,李诺.大陆内部浆控高温热液矿床成矿流体性质及其与岛弧区同类矿床的差异. 岩石学报, 2009, 25(10): 2477~2508
    邓军,王庆飞,黄定华等.铜陵矿集区构造-流体-成矿系统演化格架.地学前缘,2004, 11(1): 121~128
    杜安道,何红廖,殷万宁等.辉钼矿的铼-锇同位素地质年龄测定方法研究.地质学报, 1994, 68 (4): 339~347
    杜杨松,秦新龙,李铉具.安徽铜陵地区中生代幔源岩浆底侵作用.岩石矿物学杂志, 2004, 2(23): 109~116
    华仁民.成矿过程中由流体混合而导致金属沉淀的研究.地球科学进展, 1994, 9(4): 15~22
    李晶,孙亚莉,何克等.辉钼矿Re-Os同位素定年方法的改进与应用.岩石学报, 2010, 26(2): 642~648
    李秉伦,谢奕汉,王兰英.根据矿物中包裹体的研究对玢岩铁矿的新认识.矿床地质, 1983, (2): 25~32
    李立平,邵洁涟.贵池铜山铜矿微量元素地球化学特征研究.地质与勘探, 1994, 3: 9~13
    林新多,许国建.岩浆成因矽卡岩的某些特征及形成机制探讨.现代地质, 1989, 3(3): 351~358
    林新多.岩浆-热液过渡型矿床.武汉:中国地质大学出版社, 1999: 44~78
    刘斌,沈昆.流体包裹体热力学.北京:地质出版社, 1999: 44~114
    刘文灿,高德臻,储国正.安徽铜陵地区构造变形分析及成矿预测.北京:地质出版社, 1996
    卢焕章,范宏瑞,倪培等.流体包裹体.北京:科学出版社, 2004: 1~ 487
    吕俊武.铜山岩体特征研究.矿产与地质, 2000, l(3): 172~174
    毛景文,邵拥军,谢桂清等.长江中下游成矿带铜陵矿集区铜多金属矿床模型.矿床地质, 2009, 28(2): 109~119
    芮宗瑶,赵一鸣,王龙生等.挥发份在夕卡岩型和斑岩型矿床形成中的作用.矿床地质, 2003, 22(1): 141~148
    孙亚力,张立明,张洪洲.安徽池州铜山铜矿深部找矿实践与启示.云南地质, 2008, 27(1):40~45
    唐永成,吴言昌,储国正等.安徽沿江地区铜金多金属矿床地质.北京:地质出版社, 1998
    涂光炽.地质学中的若干思维方法田.地质与勘探, 1981, (7): 1~5
    王勇.铜山铜矿F1断裂带构造控矿特征分析.矿产与地质, 2003, 17(4): 530~532
    吴言昌,常印佛.关于岩浆矽卡岩问题.地学前缘, 1998, 5(4): 291~301
    邢凤呜.扬子岩浆岩带东段基性岩地球化学.地球化学, 1998, 27(3): 258~268
    许国建,林新多.安徽长龙山矽卡岩浆型铁矿床成因探讨.地球科学-中国地质大学学报, 1990, (6): 649~656
    姚鹏,顾雪祥,李金高等.甲马铜多金属矿床层控矽卡岩流体包裹体特征及其成因意义.
    成都理工大学学报(自然科学版), 2006, 33(3): 285~293
    俞沧海.贵池铜山铜矿床成因探讨.地质与勘探, 2001, 37(2): 12~16
    俞沧海.贵池铜山岩体演化与成矿的关系.矿产与地质, 1999, 13(5): 274~78
    俞沧海.铜山铜矿矿床地质特征及找矿方向探讨.有色矿山, 2002, 31(3): l~3
    翟裕生.长江中下游地区铁铜(金)成矿规律.北京:地质出版社, 1992: 1~235
    张静,陈衍景,张复新等.陕西金龙山卡林型金矿带成矿流体地球化学研究.矿床地质, 2002, 21(3): 283~291
    张静,祁进平,仇建军等.河南省内乡县银洞沟银矿床流体成分研究.岩石学报, 2007, 23(9): 2217~2226
    张德会.矿物包裹体液相成分特征及其矿床成因意义.地球科学, 1992, 17(6): 677~688
    张德会.流体的沸腾和混合在热液成矿中的意义.地球科学进展, 1997, 12(6): 546~552
    张叔贞,凌其聪.矽卡岩浆型铜矿床特征-以安徽铜陵东狮子山铜矿床为例.地球科学, 1993, 18 (6): 801~809
    赵斌,李院生,赵劲松.岩浆成因夕卡岩的包裹体证据.地球化学, 1995, 24(2): 198~200
    赵斌.中国主要矽卡岩及矽卡岩型矿床.北京:科学出版社, 1989: 1~342
    赵旭林.安徽铜山铜矿三维模拟及构造成矿动力学: [硕士学位论文].湖南:中南大学, 2009: 11~17
    赵一鸣.夕卡岩矿床研究的某些重要新进展.矿床地质, 2002, 21(2): 113~120
    赵一鸣.中国夕卡岩矿床.北京:地质出版社, 1989: 298~317
    周曙光.安徽铜山矿床成矿物质来源及成矿作用探讨.矿产与地质, 2003, 17(5): 610~612
    周珣若,任进.长江中下游中生代花岗岩.北京:地质出版社, 1994: 1~119
    周余谔,张宜勇,苏其树.安徽铜山铜矿床地球化学特征及其成因.安徽地质, 1996, 6(2): 54~68
    左胜平.铜山铜矿找矿预测.矿业快报, 2003, 12: 25

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