新疆哈密卡拉塔格块状硫化物矿床金银赋存状态研究
|
摘要
新疆哈密红海-黄土坡VMS矿床位于东天山卡拉塔格隆起带,是卡拉塔格矿集区内新发现的块状硫化物矿床。矿体产于卡拉塔格隆起带核部火山-沉积岩建造中,具有典型的VMS型矿床"上层下脉"二元结构特征。该矿床中含金硫化物矿石主要有块状黄铁矿-黄铜矿、块状黄铁矿-黄铜矿-闪锌矿、块状黄铁矿-闪锌矿-黄铜矿和块状闪锌矿。文中在对各类含金硫化物矿石进行详细的矿相学研究基础上,结合扫描电子显微镜与能谱仪联用技术(SEM/EDS),对硫化物样品中金、银的赋存状态进行研究。结果表明,4种块状硫化物中的主要矿物形成于多个期次,主要包括VMS成矿期(黄铁矿阶段、闪锌矿-黄铜矿-黝铜矿-方铅矿阶段、石英-重晶石阶段)、热液叠加期(石英-黄铁矿-黄铜矿-闪锌矿-方铅矿阶段)和表生期(铜蓝-纤铁矿阶段)。矿区首次发现4颗金银金属互化物(银金矿、碲银矿),其较大的化学成分差异指示了热液环境由中酸性-中性转变为更有利于Au、Ag迁移沉淀的偏碱性。后期的偏碱性热液对VMS成矿期形成矿物产生了交代作用,使得Au、Ag活化再富集。由于后期热液叠加改造,红海VMS型矿床中Au、Ag不仅赋存于VMS成矿期后期中低温闪锌矿-黄铜矿阶段,也赋存于VMS成矿期早期中高温黄铁矿阶段,并贯穿整个热液叠加期。各含金矿物组合中除4颗金银金属互化物外Au多呈显微不可见状态,推测Au、Ag主要以原子或离子形式赋存于矿物晶格中或矿物空位处。
The Kalatag region in eastern Tianshan,NW China contains a number of economically important Cu deposits,including the Honghai-Huangtupo VMS-type Cu-Zn deposit hosted in the volcanic-sedimentary rocks of the Late Ordovician to Early Silurian Daliugou Formation.The characteristic dualistic structure of the CuZn deposit features concordant massive sulfide and discordant vein-type ores in the footwall strata.The massive auriferous sulfide ores consist of pyrite-chalcopyrite,pyrite-chalcopyrite-sphalerite,pyrite-sphaleritechalcopyrite and sphalerite.Based on detailed mineragraphic analysis of various kinds of auriferous sulfide ores,and combined with scanning electron microscope and energy dispersive spectrometer hyphenated techniques(SEM/EDS),we clarified that the principle ore minerals are pyrite,chalcopyrite and sphalerite,while tetrahedrite,galena and pyrrhotite occur in minor quantities;gangue minerals are mainly quartz,sericite and barite with lesser chlorite,plagioclase and carbonate.Mineralization of the Honghai deposit can be divided into three periods:VMS mineralization,hydrothermal overlapping and supergene periods.The VMS mineralization period can be further subdivided into pyrite,sphalerite-chalcopyrite-tetrahedrite-galena and quartz-barite stages.Four grains of natural gold and silver metallic mineral were found in this deposit for the first time,their very different chemical contents inferred that the hydrothermal environment went through a transformation from intermediate-acid to alkalescent,which benefited Au and Ag transport.Au and Ag were activated and re-enriched through metasomatism of minerals formed in the VMS mineralization period,by the late alkalescent hydrothermal solution.Through metasomatism,Au and Ag mineralization occurred not only in the intermediate-hypothermal sphalerite-chalcopyrite stage of the late VMS mineralization period, but also in the intermediate-hyperthermal pyrite stage of the early VMS mineralization as well as the whole hydrothermal overlapping periods.In all mineral assemblages,except the four mineral grains,Au and Ag could not be observed under the electron microscope,which may illustrate that Au and Ag in this deposit mainly occur as constituents of the crystal lattice of host minerals.
The Kalatag region in eastern Tianshan,NW China contains a number of economically important Cu deposits,including the Honghai-Huangtupo VMS-type Cu-Zn deposit hosted in the volcanic-sedimentary rocks of the Late Ordovician to Early Silurian Daliugou Formation.The characteristic dualistic structure of the CuZn deposit features concordant massive sulfide and discordant vein-type ores in the footwall strata.The massive auriferous sulfide ores consist of pyrite-chalcopyrite,pyrite-chalcopyrite-sphalerite,pyrite-sphaleritechalcopyrite and sphalerite.Based on detailed mineragraphic analysis of various kinds of auriferous sulfide ores,and combined with scanning electron microscope and energy dispersive spectrometer hyphenated techniques(SEM/EDS),we clarified that the principle ore minerals are pyrite,chalcopyrite and sphalerite,while tetrahedrite,galena and pyrrhotite occur in minor quantities;gangue minerals are mainly quartz,sericite and barite with lesser chlorite,plagioclase and carbonate.Mineralization of the Honghai deposit can be divided into three periods:VMS mineralization,hydrothermal overlapping and supergene periods.The VMS mineralization period can be further subdivided into pyrite,sphalerite-chalcopyrite-tetrahedrite-galena and quartz-barite stages.Four grains of natural gold and silver metallic mineral were found in this deposit for the first time,their very different chemical contents inferred that the hydrothermal environment went through a transformation from intermediate-acid to alkalescent,which benefited Au and Ag transport.Au and Ag were activated and re-enriched through metasomatism of minerals formed in the VMS mineralization period,by the late alkalescent hydrothermal solution.Through metasomatism,Au and Ag mineralization occurred not only in the intermediate-hypothermal sphalerite-chalcopyrite stage of the late VMS mineralization period, but also in the intermediate-hyperthermal pyrite stage of the early VMS mineralization as well as the whole hydrothermal overlapping periods.In all mineral assemblages,except the four mineral grains,Au and Ag could not be observed under the electron microscope,which may illustrate that Au and Ag in this deposit mainly occur as constituents of the crystal lattice of host minerals.
引文
[1]HANNINGTON M D,PETER J M,SCOTT S D.Gold in sea-floor polymetallic sulfide deposits[J].Economic Geology,1986,81(8):1867-1883.
[2]HANNINGTON M D,THOMPSON G,RONA P A,et al.Gold and native copper in supergene sulphides from the MidAtlantic Ridge[J].Nature,1988,333(6168):64-66.
[3]LAROCQUE A C L.The occurrence of gold in sulfide deposits of the Tag hydrothermal field,Mid-Atlantic ridge[J].The Canadian Mineralogist,1995,33:1285-1310.
[4]HERZIG P M,HANNINGTON M D,FOUQUET Y,et al.Gold-rich polymetallic sulfides from the Lau back arc and implications for the geochemistry of gold in sea-floor hydrothermal systems of the Southwest Pacific[J].Economic Geology,1993,88(8):2182-2209.
[5]BINNS R A,SCOTT S D,BOGDANOV Y A,et al.Hydrothermal oxide and gold-rich sulfate deposits of Franklin Seamount,western Woodlark Basin,Papua New Guinea[J].Economic Geology,1993,88(8):2122-2153.
[6]MURPHY P J,MEYER G.A gold-copper association in ultramafic-hosted hydrothermal sulfides from the Mid-Atlantic Ridge[J].Economic Geology,1998,93(7):1076-1083.
[7]郑明华,刘建明,周渝峰,等.当前金矿地质研究中的若干新认识及其找矿意义[J].河南地质,1990,8(3):1-16.
[8]刘家军,郑明华,顾雪祥,等.海底喷流作用对金富集成矿的意义[J].矿产与地质,1997,11(5):289-295.
[9]HERZIG P M,HANNINGTON M D.Polymetallic massive sulfides at the modern seafloor a review[J].Ore Geology Reviews,1995,10(2):95-115.
[10]HANNINGTON M,HERZIG P,SCOTT S,et al.Comparative mineralogy and geochemistry of gold-bearing sulfide deposits on the mid-ocean ridges[J].Marine Geology,1991,101(1/2/3/4):217-248.
[11]MEYER G,CAMBON P,ETOUBLEAU J,et al.Gold-silver mineralization in submarine hydrothermal sulphides:INAA results after ten years of intense prospecting[J].Journal of Radioanalytical and Nuclear Chemistry,2000,244:583.
[12]MOSS R,SCOTT S D,BINNS R A.Gold content of eastern Manus basin volcanic rocks:implications for enrichment in associated hydrothermal precipitates[J].Economic Geology,2001,96(1):91-107.
[13]王叶剑,韩喜球,PETERSEN S,等.洋中脊超镁铁岩硫化物矿床的微量元素富集特征:激光剥蚀电感耦合等离子体质谱微区分析[J].矿物学报,2015(增刊1):790-791.
[14]吴仲玮,孙晓明,戴瑛知,等.中印度洋海岭Edmond热液区块状硫化物中自然金的发现及其意义[J].岩石学报,2011,27(12):3749-3762.
[15]王琰,孙晓明,吴仲玮,等.西南印度洋超慢速扩张脊海底热液硫化物中金银矿物的富集特征及富集机制研究[J].光谱学与光谱分析,2014,34(12):3327-3332.
[16]赖乙雄,陆仲和,曾秀英,等.铜矿石中金银赋存状态的研究[J].地球化学,1980(4):408-413.
[17]王先儒.对金的工艺矿物学工作规范化一些问题的建议[J].黄金,1984(2):12-15.
[18]毛启贵,方同辉,王京彬,等.东天山卡拉塔格早古生代红海块状硫化物矿床精确定年及其地质意义[J].岩石学报,2010,26(10):3017-3026.
[19]DENG X H,WANG J B,PIRAJNO F,et al.Re-Os dating of chalcopyrite from selected mineral deposits in the Kalatag district in the eastern Tianshan Orogen,China[J].Ore Geology Reviews,2016,77:72-81.
[20]邓小华,王京彬,王玉往,等.东天山卡拉塔格红石铜矿地质特征及矿床成因初步探讨[J].矿产勘查,2014,5(2):159-168.
[21]CHEN L,WANG J B,BAGAS L,et al.Significance of adakites in petrogenesis of Early Silurian magmatism at the Yudai copper deposit in the Kalatag district,NW China[J].Ore Geology Reviews,2017,91:780-794.
[22]SENGOR A M C,NATALIN B A.Paleotectonics of Asia:fragments of synthesis[M]∥YIN A,HARRISON T M.The tectonic evolution of Asia.Cambridge:Cambridge University Press,1996:486-640.
[23]XIAO W J,HAN C M,YUAN C,et al.Middle Cambrian to Permian subduction-related accretionary orogenesis of Northern Xinjiang,NW China:implications for the tectonic evolution of central Asia[J].Journal of Asian Earth Sciences,2008,32(2/3/4):102-117.
[24]CHEN Y J,PIRAJNO F,WU G,et al.Epithermal deposits in north Xinjiang,NW China[J].International Journal of Earth Sciences,2012(101):889-917.
[25]王京彬,王玉往,何志军.东天山大地构造演化的成矿示踪[J].中国地质,2006,33(3):461-469.
[26]秦克章,方同辉,王书来,等.吐哈盆地南缘古生代“天窗”卡拉塔格铜金矿化区的发现及其成矿潜力[J].中国地质,2001,28(3):16-23.
[27]冉丽,刘正桃,杨自安,等.新疆东部卡拉塔格地区构造影像特征分析[J].地质与勘探,2010,46(6):1099-1105.
[28]韩业鸣,刘正桃,方同辉,等.红石铜矿裂隙构造分布特征研究[J].科学技术与工程,2011,11(20):4709-4714.
[29]DENG X H,WANG J B,SANTOSH M,et al.Early Paleozoic volcanic rocks with VMS mineralization from eastern Tianshan Orogen:implication for tectonic evolution[J].Geological Journal,2017.http:∥doi.org/10.1002/gj.3046.
[30]MAO Q,YU M,XIAO W,et al.Skarn-mineralized porphyry adakites in the Harlik arc at Kalatage,E.Tianshan(NW China):slab melting in the Devonian-Early Carboniferous in the southern Central Asian Orogenic Belt[J].Journal of Asian Earth Sciences,2017,153:365-378.
[31]毛启贵,王京彬,方同辉,等.东天山卡拉塔格矿带红海VMS型矿床S、Pb同位素地球化学研究[J].矿床地质,2015,34(4):730-744.
[32]PENG X T,ZHOU H Y,YAO H Q,et al.Microbe-related precipitation of iron and silica in the Edmond deep-sea hydrothermal vent field on the Central Indian Ridge[J].Chinese Science Bulletin,2007,52:3233-3238.
[33]PAL'YANOVA G.Physicochemical modeling of the coupled behavior of gold and silver in hydrothermal processes:gold fineness,Au/Ag ratios and their possible implications[J].Chemical Geology,2008,255(3):399-413.
[34]HANNINGTON M D,SCOTT S D.Sulfidation equilibria as guides to gold mineralization in volcanogenic massive sulfides:evidence from sulfide mineralogy and the composition of sphalerite[J].Economic Geology,1989,84:1978-1995.
[35]HANNINGTON M D,TIVEY M K,LAROCQUE A C,et al.The occurrence of gold in sulfide deposits of the TAG hydrothermal field,Mid-Atlantic Ridge[J].Canadian Mineralogist,1995,33:1285-1131.
[36]BINNS R A,PARR J M,GEMMELL J B,et al.Precious metals in barite-silica chimneys from Franklin Seamount,Woodlark Basin,Papua New Guinea[J].Marine Geology,1997,142:119-141.
[2]HANNINGTON M D,THOMPSON G,RONA P A,et al.Gold and native copper in supergene sulphides from the MidAtlantic Ridge[J].Nature,1988,333(6168):64-66.
[3]LAROCQUE A C L.The occurrence of gold in sulfide deposits of the Tag hydrothermal field,Mid-Atlantic ridge[J].The Canadian Mineralogist,1995,33:1285-1310.
[4]HERZIG P M,HANNINGTON M D,FOUQUET Y,et al.Gold-rich polymetallic sulfides from the Lau back arc and implications for the geochemistry of gold in sea-floor hydrothermal systems of the Southwest Pacific[J].Economic Geology,1993,88(8):2182-2209.
[5]BINNS R A,SCOTT S D,BOGDANOV Y A,et al.Hydrothermal oxide and gold-rich sulfate deposits of Franklin Seamount,western Woodlark Basin,Papua New Guinea[J].Economic Geology,1993,88(8):2122-2153.
[6]MURPHY P J,MEYER G.A gold-copper association in ultramafic-hosted hydrothermal sulfides from the Mid-Atlantic Ridge[J].Economic Geology,1998,93(7):1076-1083.
[7]郑明华,刘建明,周渝峰,等.当前金矿地质研究中的若干新认识及其找矿意义[J].河南地质,1990,8(3):1-16.
[8]刘家军,郑明华,顾雪祥,等.海底喷流作用对金富集成矿的意义[J].矿产与地质,1997,11(5):289-295.
[9]HERZIG P M,HANNINGTON M D.Polymetallic massive sulfides at the modern seafloor a review[J].Ore Geology Reviews,1995,10(2):95-115.
[10]HANNINGTON M,HERZIG P,SCOTT S,et al.Comparative mineralogy and geochemistry of gold-bearing sulfide deposits on the mid-ocean ridges[J].Marine Geology,1991,101(1/2/3/4):217-248.
[11]MEYER G,CAMBON P,ETOUBLEAU J,et al.Gold-silver mineralization in submarine hydrothermal sulphides:INAA results after ten years of intense prospecting[J].Journal of Radioanalytical and Nuclear Chemistry,2000,244:583.
[12]MOSS R,SCOTT S D,BINNS R A.Gold content of eastern Manus basin volcanic rocks:implications for enrichment in associated hydrothermal precipitates[J].Economic Geology,2001,96(1):91-107.
[13]王叶剑,韩喜球,PETERSEN S,等.洋中脊超镁铁岩硫化物矿床的微量元素富集特征:激光剥蚀电感耦合等离子体质谱微区分析[J].矿物学报,2015(增刊1):790-791.
[14]吴仲玮,孙晓明,戴瑛知,等.中印度洋海岭Edmond热液区块状硫化物中自然金的发现及其意义[J].岩石学报,2011,27(12):3749-3762.
[15]王琰,孙晓明,吴仲玮,等.西南印度洋超慢速扩张脊海底热液硫化物中金银矿物的富集特征及富集机制研究[J].光谱学与光谱分析,2014,34(12):3327-3332.
[16]赖乙雄,陆仲和,曾秀英,等.铜矿石中金银赋存状态的研究[J].地球化学,1980(4):408-413.
[17]王先儒.对金的工艺矿物学工作规范化一些问题的建议[J].黄金,1984(2):12-15.
[18]毛启贵,方同辉,王京彬,等.东天山卡拉塔格早古生代红海块状硫化物矿床精确定年及其地质意义[J].岩石学报,2010,26(10):3017-3026.
[19]DENG X H,WANG J B,PIRAJNO F,et al.Re-Os dating of chalcopyrite from selected mineral deposits in the Kalatag district in the eastern Tianshan Orogen,China[J].Ore Geology Reviews,2016,77:72-81.
[20]邓小华,王京彬,王玉往,等.东天山卡拉塔格红石铜矿地质特征及矿床成因初步探讨[J].矿产勘查,2014,5(2):159-168.
[21]CHEN L,WANG J B,BAGAS L,et al.Significance of adakites in petrogenesis of Early Silurian magmatism at the Yudai copper deposit in the Kalatag district,NW China[J].Ore Geology Reviews,2017,91:780-794.
[22]SENGOR A M C,NATALIN B A.Paleotectonics of Asia:fragments of synthesis[M]∥YIN A,HARRISON T M.The tectonic evolution of Asia.Cambridge:Cambridge University Press,1996:486-640.
[23]XIAO W J,HAN C M,YUAN C,et al.Middle Cambrian to Permian subduction-related accretionary orogenesis of Northern Xinjiang,NW China:implications for the tectonic evolution of central Asia[J].Journal of Asian Earth Sciences,2008,32(2/3/4):102-117.
[24]CHEN Y J,PIRAJNO F,WU G,et al.Epithermal deposits in north Xinjiang,NW China[J].International Journal of Earth Sciences,2012(101):889-917.
[25]王京彬,王玉往,何志军.东天山大地构造演化的成矿示踪[J].中国地质,2006,33(3):461-469.
[26]秦克章,方同辉,王书来,等.吐哈盆地南缘古生代“天窗”卡拉塔格铜金矿化区的发现及其成矿潜力[J].中国地质,2001,28(3):16-23.
[27]冉丽,刘正桃,杨自安,等.新疆东部卡拉塔格地区构造影像特征分析[J].地质与勘探,2010,46(6):1099-1105.
[28]韩业鸣,刘正桃,方同辉,等.红石铜矿裂隙构造分布特征研究[J].科学技术与工程,2011,11(20):4709-4714.
[29]DENG X H,WANG J B,SANTOSH M,et al.Early Paleozoic volcanic rocks with VMS mineralization from eastern Tianshan Orogen:implication for tectonic evolution[J].Geological Journal,2017.http:∥doi.org/10.1002/gj.3046.
[30]MAO Q,YU M,XIAO W,et al.Skarn-mineralized porphyry adakites in the Harlik arc at Kalatage,E.Tianshan(NW China):slab melting in the Devonian-Early Carboniferous in the southern Central Asian Orogenic Belt[J].Journal of Asian Earth Sciences,2017,153:365-378.
[31]毛启贵,王京彬,方同辉,等.东天山卡拉塔格矿带红海VMS型矿床S、Pb同位素地球化学研究[J].矿床地质,2015,34(4):730-744.
[32]PENG X T,ZHOU H Y,YAO H Q,et al.Microbe-related precipitation of iron and silica in the Edmond deep-sea hydrothermal vent field on the Central Indian Ridge[J].Chinese Science Bulletin,2007,52:3233-3238.
[33]PAL'YANOVA G.Physicochemical modeling of the coupled behavior of gold and silver in hydrothermal processes:gold fineness,Au/Ag ratios and their possible implications[J].Chemical Geology,2008,255(3):399-413.
[34]HANNINGTON M D,SCOTT S D.Sulfidation equilibria as guides to gold mineralization in volcanogenic massive sulfides:evidence from sulfide mineralogy and the composition of sphalerite[J].Economic Geology,1989,84:1978-1995.
[35]HANNINGTON M D,TIVEY M K,LAROCQUE A C,et al.The occurrence of gold in sulfide deposits of the TAG hydrothermal field,Mid-Atlantic Ridge[J].Canadian Mineralogist,1995,33:1285-1131.
[36]BINNS R A,PARR J M,GEMMELL J B,et al.Precious metals in barite-silica chimneys from Franklin Seamount,Woodlark Basin,Papua New Guinea[J].Marine Geology,1997,142:119-141.