合仁坪金矿H-O-S-Pb同位素地球化学特征及其成因机制
|
摘要
对合仁坪金矿的H-O-S-Pb同位素地球化学分析研究显示,其硫化物的δ34S值介于-4.8‰～2.0‰之间,硫化物的206Pb/204Pb比值为17.419～17.436,207Pb/204Pb比值为15.519～15.535,208Pb/204Pb比值为37.86～37.90.成矿流体的δD介于-62.3‰～-53.0‰之间,δ18O介于4.2‰～11.8‰之间.合仁坪金矿的S,Pb,O和H同位素研究结果表明,成矿物质具有深源特征,成矿流体为岩浆热液水来源,成矿作用存在明显的氧化还原特征,并形成本区特色的褪色蚀变带.该金矿是一个与深部岩浆作用有关的金矿床,找矿应着眼于赋矿地层内的氧化还原界面,褪色蚀变带是其主要的找矿标志.
The geochemical analysis of H-O-S-Pb isotopes in the Herenping Gold Mine was carried out.The δ34 S values of sulfides from ore lie in -4.8‰～2.0‰.The ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb from sulfide ores are 17.419～17.436,15.519～15.535 and 37.86～37.90,respectively.The δD values of the fluid fall in -62.3‰～-53.0‰,and the δ18O values of the fluid are 4.2‰～11.8‰.These sulfur,lead,hydrogen and oxygen composition indicate that the ore-forming materials originate from the depth and the ore-forming fluid from magmatic hydrothermal,and mineralization has the characteristics of redox which formed the faded alteration zone in the region.Considering that the Herenping gold deposit is related to the deep magmatism,the ore prospecting should focus on the redox interface in the host strata and the faded alteration is the main indicator for the deposit.
The geochemical analysis of H-O-S-Pb isotopes in the Herenping Gold Mine was carried out.The δ34 S values of sulfides from ore lie in -4.8‰～2.0‰.The ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb from sulfide ores are 17.419～17.436,15.519～15.535 and 37.86～37.90,respectively.The δD values of the fluid fall in -62.3‰～-53.0‰,and the δ18O values of the fluid are 4.2‰～11.8‰.These sulfur,lead,hydrogen and oxygen composition indicate that the ore-forming materials originate from the depth and the ore-forming fluid from magmatic hydrothermal,and mineralization has the characteristics of redox which formed the faded alteration zone in the region.Considering that the Herenping gold deposit is related to the deep magmatism,the ore prospecting should focus on the redox interface in the host strata and the faded alteration is the main indicator for the deposit.
引文
[1]Morelli R,Creaser R A,Seltman R,et al.Age and source constraints for the giant Muruntau gold deposit,Uzbekistan,from coupled Re-Os-He isotopes in arsenopyrite[J].Geology,2007,35(9):795-798.
[2]Thomas H V,Large R E,Bull S W,et al.Pyrite and pyrrhotite textures and composition in sediments,laminated quartz veins,and reef at Bendigo gold mine,Australia:insights for ore genesis[J].Economic Geology,2011,106(1):1-31.
[3]毛景文,李红艳.江南古陆某些金矿床成因讨论[J].地球化学,1997,26(5):71-81.(Mao Jing-wen,Li Hong-yan.Research on genesis of the gold deposits in the Jiangnan terrain[J].Geochimica,1997,26(5):71-81.)
[4]邓穆昆,彭建堂,胡诗倩,等.湘西合仁坪金矿床硫、铅同位素地球化学[J].矿床地质,2016,35(5):953-965.(Deng Mu-kun,Peng Jian-tang,Hu Shi-qian,et al.Sulfur and lead isotope geochemistry of Herenping gold deposit,western Hunan[J].Mineral Deposits,2016,35(5):953-965.)
[5]Clayton R N,O'Neil J R,Mayeda T K.Oxygen isotope exchange between quartz and water[J].Journal of Geophysical Research,1972,77(17):3057-3067.
[6]罗献林.论湖南前寒武系金矿床的成矿物质来源[J].桂林冶金地质学院学报,1990,10(1):13-26.(Luo Xian-lin.On the source of ore forming substances of Precambrian gold deposits in Hunan Province[J].Journal of Guilin College of Geology,1990,10(1):13-26.)
[7]Sheppard S M F.Characterization and isotopic variations in natural waters[J].Reviews in Mineralogy,1986,16(3):165-183.
[8]Pirajno F.Hydrothermal process and mineral systems[M].Berlin:Springer,2009.
[9]Zartman R E,Doe B R.Plumbotectonics-the model[J].Tectonophysics,1981,75(1/2):135-162.
[10]Ohmoto H,Goldhaber M B.Sulfur and carbon isotopes[M]//Geochemistry of Hydrothermal Ore Deposits.3rd ed.New York:John Wiley and Sons,1997:517-611.
[11]Ohmoto H,Rye R O.Isotopes of sulfur and carbon[M]//Geochemistry of Hydrothermal Ore Deposits.2nd ed.New York:John Wiley and Sons,1979:509-567.
[12]Cameron E M,Hattori K.Archean gold mineralization and oxidized hydrothermal fluids[J].Economic Geology,1987,82(5):1177-1191.
[13]Hagemann S G,Groves D I,Ridley J R.The Wiluna lode-gold deposits,western Australia:an example of a high crustal-level Archaean lode-gold system[M]//Current Research in Geology Applied to Ore Deposits.Granada:University of Granada,1993:469-472.
[14]Yang S X,Blum N.A fossil hydrothermal system or a source bed in the Madiyi formation near the Xiangxi Au-Sb-W deposit,NW Hunan,PR China?[J].Chemical Geology,1999,155(1/2):151-169.
[15]朱明新,王河锦.长沙-澧陵-浏阳一带冷家溪群及板溪群的甚低级变质作用[J].岩石学报,2001,17(2):291-300.(Zhu Ming-xin,Wang He-jin.Very low-grade metamorphism of the Lengjiaxi and Banxi Groups around the area of ChangshaLiling-Liuyang,Hunan Province,China[J].Acta Petrologica Sinica,2001,17(2):291-300.)
[16]Phillips G N,Powell R.Formation of gold deposits:review and evaluation of the continuum model[J].Earth-Science Reviews,2009,94(1/2/3/4):1-21.
[17]Phillips G N,Powell R.Formation of gold deposits:a metamorphic devolatilization model[J].Journal of Metamorphic Geology,2010,28(6):689-718.
[2]Thomas H V,Large R E,Bull S W,et al.Pyrite and pyrrhotite textures and composition in sediments,laminated quartz veins,and reef at Bendigo gold mine,Australia:insights for ore genesis[J].Economic Geology,2011,106(1):1-31.
[3]毛景文,李红艳.江南古陆某些金矿床成因讨论[J].地球化学,1997,26(5):71-81.(Mao Jing-wen,Li Hong-yan.Research on genesis of the gold deposits in the Jiangnan terrain[J].Geochimica,1997,26(5):71-81.)
[4]邓穆昆,彭建堂,胡诗倩,等.湘西合仁坪金矿床硫、铅同位素地球化学[J].矿床地质,2016,35(5):953-965.(Deng Mu-kun,Peng Jian-tang,Hu Shi-qian,et al.Sulfur and lead isotope geochemistry of Herenping gold deposit,western Hunan[J].Mineral Deposits,2016,35(5):953-965.)
[5]Clayton R N,O'Neil J R,Mayeda T K.Oxygen isotope exchange between quartz and water[J].Journal of Geophysical Research,1972,77(17):3057-3067.
[6]罗献林.论湖南前寒武系金矿床的成矿物质来源[J].桂林冶金地质学院学报,1990,10(1):13-26.(Luo Xian-lin.On the source of ore forming substances of Precambrian gold deposits in Hunan Province[J].Journal of Guilin College of Geology,1990,10(1):13-26.)
[7]Sheppard S M F.Characterization and isotopic variations in natural waters[J].Reviews in Mineralogy,1986,16(3):165-183.
[8]Pirajno F.Hydrothermal process and mineral systems[M].Berlin:Springer,2009.
[9]Zartman R E,Doe B R.Plumbotectonics-the model[J].Tectonophysics,1981,75(1/2):135-162.
[10]Ohmoto H,Goldhaber M B.Sulfur and carbon isotopes[M]//Geochemistry of Hydrothermal Ore Deposits.3rd ed.New York:John Wiley and Sons,1997:517-611.
[11]Ohmoto H,Rye R O.Isotopes of sulfur and carbon[M]//Geochemistry of Hydrothermal Ore Deposits.2nd ed.New York:John Wiley and Sons,1979:509-567.
[12]Cameron E M,Hattori K.Archean gold mineralization and oxidized hydrothermal fluids[J].Economic Geology,1987,82(5):1177-1191.
[13]Hagemann S G,Groves D I,Ridley J R.The Wiluna lode-gold deposits,western Australia:an example of a high crustal-level Archaean lode-gold system[M]//Current Research in Geology Applied to Ore Deposits.Granada:University of Granada,1993:469-472.
[14]Yang S X,Blum N.A fossil hydrothermal system or a source bed in the Madiyi formation near the Xiangxi Au-Sb-W deposit,NW Hunan,PR China?[J].Chemical Geology,1999,155(1/2):151-169.
[15]朱明新,王河锦.长沙-澧陵-浏阳一带冷家溪群及板溪群的甚低级变质作用[J].岩石学报,2001,17(2):291-300.(Zhu Ming-xin,Wang He-jin.Very low-grade metamorphism of the Lengjiaxi and Banxi Groups around the area of ChangshaLiling-Liuyang,Hunan Province,China[J].Acta Petrologica Sinica,2001,17(2):291-300.)
[16]Phillips G N,Powell R.Formation of gold deposits:review and evaluation of the continuum model[J].Earth-Science Reviews,2009,94(1/2/3/4):1-21.
[17]Phillips G N,Powell R.Formation of gold deposits:a metamorphic devolatilization model[J].Journal of Metamorphic Geology,2010,28(6):689-718.