安徽宣城茶亭斑岩铜金矿床金的赋存状态及金铜成因联系
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摘要
安徽宣城茶亭铜金矿床是长江中下游成矿带中新发现的一个大型斑岩型矿床。本文在矿相学观察和研究的基础上,开展了矿石组成矿物的成矿金属元素化学分析和电子探针(EPMA)分析,以了解矿床矿石中金的赋存状态,确定金与铜的成因联系。茶亭铜金矿床的热液成矿期可以划分为4个阶段,应用单矿物火试金法化学分析显示,第2阶段黄铁矿(Py II)和第3阶段黄铁矿(Py III)以及相应阶段的黄铜矿均富含金,各阶段石英及第3阶段硬石膏基本不含金。矿相学观察发现"可见金",金的嵌布形式主要为包裹金、粒间金,少量裂隙金。电子探针分析表明这些"可见金"主要为银金矿,其次为自然金。"不可见金"以不均匀形式分布于黄铜矿、黄铁矿、闪锌矿、斑铜矿等硫化物矿物中,"不可见金"主要为纳米级自然金。金与铜的相关性以及金的赋存状态表明,金与铜具有密切的成因联系。Simon实验研究结果表明高温环境下铜-铁硫化物中Au的溶解度更大,结合矿物共生组合及流体包裹体均一温度测定结果可以推测,茶亭铜金矿床的成矿作用经历了从较高温度到较低温度的演化过程,随着温度的降低部分Au从铜-铁硫化物中出溶并富集为"可见金",而另一部分金仍然以"不可见金"形式分散保存于黄铜矿、黄铁矿、闪锌矿以及其它含铜硫化物矿物中。
The Chating copper-gold deposit in Xuancheng City of Anhui Province is a large porphyry deposit newly discovered in the middle and lower reaches of the Yangtze River metallogenic belt. Based on detailed ore mineragraphic research, the authors carried out the measurement of ore-forming element concentrations of main minerals from the ores by EMPA and chemical analysis, with the purpose of studying the modes of occurrence of gold and the genetic connection between gold and copper in this deposit. The hydrothermal mineralization period of the Chating copper-gold deposit was divided into 4 stages. The fire assay analysis results of single mineral show that the pyrites at the second stage( Py II), the pyrites at the third stage( Py III) and the chalcopyrites at these two stages are rich in gold, whereas the quartzs at all stages and anhydrites at the third stage contain almost no gold. " Visible gold"was found in the ores and they are mainly embedded as inclusion gold and interparticle gold, with a small amount of fissure gold. The major minerals of the "visible gold" are electrum, followed by native gold. "Invisible gold" is distributed unregularly in the sulfide minerals such as chalcopyrite, pyrite, sphalerite and bornite. And the "invisible gold" exhibits nanoparticle native gold in pyrite. The correlation between gold and copper and the modes of occurrence of gold show that gold and copper have a close genetic connection. Simon's experimental study reveals that the solubility of Au in Cu-Fe sulfide is very high at high temperature. The mineralization of the Chating copper-gold deposit underwent the evolution from high temperature to low temperature. As the temperature decreased, part of gold was exsolved from Cu-Fe sulfides and became enriched as "visible gold"; while the other part remained in the form of "invisible gold" preserved in chalcopyrite, pyrite, sphalerite and other copper-bearing sulfide minerals.
The Chating copper-gold deposit in Xuancheng City of Anhui Province is a large porphyry deposit newly discovered in the middle and lower reaches of the Yangtze River metallogenic belt. Based on detailed ore mineragraphic research, the authors carried out the measurement of ore-forming element concentrations of main minerals from the ores by EMPA and chemical analysis, with the purpose of studying the modes of occurrence of gold and the genetic connection between gold and copper in this deposit. The hydrothermal mineralization period of the Chating copper-gold deposit was divided into 4 stages. The fire assay analysis results of single mineral show that the pyrites at the second stage( Py II), the pyrites at the third stage( Py III) and the chalcopyrites at these two stages are rich in gold, whereas the quartzs at all stages and anhydrites at the third stage contain almost no gold. " Visible gold"was found in the ores and they are mainly embedded as inclusion gold and interparticle gold, with a small amount of fissure gold. The major minerals of the "visible gold" are electrum, followed by native gold. "Invisible gold" is distributed unregularly in the sulfide minerals such as chalcopyrite, pyrite, sphalerite and bornite. And the "invisible gold" exhibits nanoparticle native gold in pyrite. The correlation between gold and copper and the modes of occurrence of gold show that gold and copper have a close genetic connection. Simon's experimental study reveals that the solubility of Au in Cu-Fe sulfide is very high at high temperature. The mineralization of the Chating copper-gold deposit underwent the evolution from high temperature to low temperature. As the temperature decreased, part of gold was exsolved from Cu-Fe sulfides and became enriched as "visible gold"; while the other part remained in the form of "invisible gold" preserved in chalcopyrite, pyrite, sphalerite and other copper-bearing sulfide minerals.
引文
Barker S L L,Hickey K A,Cline J S,et al.2009.Uncloaking invisible gold:Use of Nano SIMS to evaluate gold,trace elements,and sulfur isotopes in pyrite from Carlin-type gold deposits[J].Economic Geology,104(7):897~904.
Boyle R W.1979.The geochemistry of gold and its deposits[J].Geological Survey Bulletin,280:1~584.
Chen Maohong,Mao Jingwen,Chen Zhenyu,et al.2009.Mineralogy of arsenian pyrites and arsenopyrites of Carlin-type gold deposits in Yunnan-Guizhou-Guangxi“golden triangle”area,southwestern China[J].Mineral Deposits,28(5):539~557(in Chinese).
Chen Guangyuan,Shao Wei and Sun Daisheng.1989.Genetic Mineralogy of Gold Deposits in Jiaodong Region with Emphasis on Gold Prospecting[M].Chongqing:Chongqing Publishing House,1~452(in Chinese).
Emsbo P,Hofstra A H,Lauha E A,et al.2003.Origin of high-grade gold ore,source of ore fluid components,and genesis of the Meikle and Neighboring Carlin-Type Deposits,Northern Carlin Trend,Nevada[J].Economic Geology,98(6):1 069~1 105.
Fu Shaohong,Gu Xuexiang,Wang Qian,et al.2004.The typomorphic characteristics of gold-bearing pyrites from Shuiyindong gold deposit,SW Guizhou[J].Acta Mineralogica Sinica,24(1):75~80(in Chinese).
Hu Wenxuan,Zhang Wenlan,Hu Shouxi,et al.2001.Determination of structural gold in Au-bearing arsenopyrite and its formation mechanism[J].Acta Geologica Sinica,75(3):410~418(in Chinese).
Hua Shuguang,Wang Lijuan,Jia Xiaofang,et al.2012.Occurrence and enrichment mechanism of gold in the Qiuling Carlin-Type gold deposit,Zhen'an County,Shanxi Province,China[J].Earth ScienceJournal of China University of Geosciences,37(5):989~1 002(in Chinese).
Huang Yong,Tang Juxing and Zhang Li.2014.Gold in the Xiongcun porphyry copper-gold deposit,Tibet:its distribution and significance[J].Acta Petrologica et Mineralogica,33(3):551~560(in Chinese).
Kesler S E,Chryssoulis S L and Simon G.2002.Gold in porphyry copper deposits:its abundance and fate[J].Ore Geology Reviews,21(1~2):103~124.
Kesler S E,Fortuna J,Ye Z J,et al.2003.Evaluation of the role of sulfidation in deposition of gold,screamer section of the Betze-Post Carlin-Type Deposit,Nevada[J].Economic Geology,98(6):1 137~1 157.
Li Jiuling,Zhang Guilan,Qi Feng,et al.1997.Experimental research on the migration regularity of Au in the“Fe-Au-Sb-S”System[J].Mineral Deposits,16(1):79~85(in Chinese).
Li Jiuling,Qi Feng,Xu Qingsheng,et al.2002.Ascertainment of chemically bound gold and its valence state in arsenopyrite and arsenian pyrite from Jinya Mine,Guangxi,China[J].Mineral Deposits,21(s1):1 160~1 163(in Chinese).
Li Zengsheng,Zhu Xiaoqing,Lu Huanzhang,et al.2013.Advances and current problems in the study of the occurrence of“Invisible Gold”in sulfides[J].Geological Science and Technology Information,33(3):81~86(in Chinese).
Liu Jianzhong,Xia Yong,Deng Yiming,et al.2007.Re-study on modes of gold occurrence in the Shuiyindong super-large-sized gold deposit[J].Guizhou Geology,24(3):165~169(in Chinese).
Ma Jianqin,Li Chaoyang and Wen Hanjie.1999.The status quo of research on the occurrence of Invisible Gold[J].Acta Mineralogica Sinica,19(3):335~342(in Chinese).
Reich M,Kesler S E,Utsunomiya S,et al.2005.Solubility of gold in arsenian pyrite[J].Geochimica et Cosmochimica Acta,69(11):2 781~2 796.
Rubin and Kyle.1997.Precious metal mineralogy in porphyry-,skarn-,and replacement-type ore deposits of the Ertsberg(Gunung Bijih)District,Irian Jaya,Indonesia[J].Economic Geology,92(5):535.
Sharp T G and Buseck P R.1993.The distribution of Ag and Sb in galena:inclusions versus solid solution[J].American Mineralogist,78(1~2):85~95.
Sillitoe R H.1979.Some thoughts on gold-rich porphyry copper deposits[J].Mineralium Deposita,14(2):161~174.
Simon G.1999.Geochemistarny and textures of gold-bearing arsenian pyrite,Twin Creeks,Nevada:implications for deposition of gold in Carlin-Type deposits[J].Economic Geology,94(3):405~421.
Simon G.2000.Gold in porphyry copper deposits:experimental determination of the distribution of gold in the Cu-Fe-S system at 400 to700℃[J].Economic Geology,95(2):259~270.
Simon G,Huang H,Pennerhahn J E,et al.1999.Oxidation state of gold and arsenic in gold-bearing arsenian pyrite[J].American Mineralogist,84(7~8):1 071~1 079.
Su Wenchao,Zhang Hongtao,Xia Bin,et al.2006.Visible gold in arsenian pyrite at the Shuiyindong Carlin-Type gold deposit,Guizhou,China[J].Acta Mineralogica Sinica,26(3):257~260(in Chinese).
Tomkins A G and Mavrogenes J A.2001.Redistribution of gold within arsenopyrite and lollingite during Pro-and retrograde metamorphism:application to timing of mineralization[J].Economic Geology,96(3):525~534.
Ulrich T,Gunther D and Heinrich C A.2002.The evolution of a porphyry Cu-Au deposit,Based on LA-ICP-MS analysis of fluid inclusions:Bajo de la Alumbrera,Argentina[J].Economic Geology,97(8):1 889~1 920.
Wang Kuiren,Zhou Youqin,Li Fanqing,et al.1992.Gold mine of Guangxi Microgranular gold occurrence of proton probe and scanning electron microscopy study[J].Chinese Science Bulletin,37(9):832~835(in Chinese).
Wang Meng.2017.A study on the geological and geochemical characteristics and genesis of the Chating Cu-Au ore deposit in Xuancheng City,Anhui Province[D].Hefei:Master Thesis of Hefei University of Technology,1~70(in Chinese).
Xie Yuling,Chen Wei,Li Lamei,et al.2010.Mineral assemblage,gold and silver occurrence and process properties of Nongruri Gold Deposit of Tibet[J].Journal of University of Science and Technology Beijing,32(5):543~551(in Chinese).
Zhang Zhenru and Yang Sixue.1986.The study of the fineness of gold[J].Geology and Prospecting,22(11):38~39(in Chinese).
陈懋弘,毛景文,陈振宇,等.2009.滇黔桂“金三角”卡林型金矿含砷黄铁矿和毒砂的矿物学研究[J].矿床地质,28(5):539~557.
陈光远,绍伟,孙岱生.1989.胶东金矿成因矿物学与找矿[M].重庆:重庆出版社,1~452.
付绍洪,顾雪祥,王乾,等.2004.黔西南水银洞金矿床载金黄铁矿标型特征[J].矿物学报,24(1):75~80.
胡文,张文兰,胡受奚,等.2001.含金毒砂中晶格金的确定及其形成机理研究[J].地质学报,75(3):410~418.
华曙光,王力娟,贾晓芳,等.2012.陕西镇安丘岭卡林型金矿金的赋存状态和富集机理[J].地球科学---中国地质大学学报,37(5):989~1 002.
黄勇,唐菊兴,张丽.2014.西藏雄村斑岩铜金矿床金的赋存状态及其意义[J].岩石矿物学杂志,33(3):551~560.
李九玲,张桂兰,亓锋,等.1997.“Fe-Au-Sb-S”体系中金迁移规律的实验研究[J].矿床地质,16(1):79~85.
李九玲,亓锋,徐庆生,等.2002.广西金牙金矿毒砂和黄铁矿中晶格金的确认及其价态研究[J].矿床地质,21(s1):1 160~1 163.
李胜荣,陈光远,邵伟,等.1996.胶东乳山金矿田成因矿物学[M].北京:地质出版社,1~116.
李增胜,朱笑青,卢焕章,等.2013.硫化物中“不可见金”的赋存状态研究进展[J].地质科技情报,33(3):81~86.
刘建中,夏勇,邓一明,等.2007.贵州水银洞超大型金矿床金的赋存状态再研究[J].贵州地质,24(3):165~169.
马建秦,李朝阳,温汉捷.1999.不可见金赋存状态研究现状[J].矿物学报,19(3):335~342.
苏文超,张弘弢,夏斌,等.2006.贵州水银洞卡林型金矿床首次发现大量次显微-显微可见自然金颗粒[J].矿物学报,26(3):257~260.
王奎仁,周有勤,李凡庆,等.1992.广西金牙金矿微细粒金赋存状态的质子探针和扫描电镜研究[J].科学通报,37(9):832~835.
王蒙.2017.安徽宣城茶亭铜金矿床地质和地球化学特征及成因研究[D].合肥:合肥工业大学硕士论文,1~70.
谢玉玲,陈伟,李腊梅,等.2010.西藏弄如日金矿矿石矿物组成、金银赋存状态及工艺特性[J].北京科技大学学报,32(5):543~551.
张振儒,杨思学.1986.金的成色研究[J].地质与勘探,22(11):38~39.
Boyle R W.1979.The geochemistry of gold and its deposits[J].Geological Survey Bulletin,280:1~584.
Chen Maohong,Mao Jingwen,Chen Zhenyu,et al.2009.Mineralogy of arsenian pyrites and arsenopyrites of Carlin-type gold deposits in Yunnan-Guizhou-Guangxi“golden triangle”area,southwestern China[J].Mineral Deposits,28(5):539~557(in Chinese).
Chen Guangyuan,Shao Wei and Sun Daisheng.1989.Genetic Mineralogy of Gold Deposits in Jiaodong Region with Emphasis on Gold Prospecting[M].Chongqing:Chongqing Publishing House,1~452(in Chinese).
Emsbo P,Hofstra A H,Lauha E A,et al.2003.Origin of high-grade gold ore,source of ore fluid components,and genesis of the Meikle and Neighboring Carlin-Type Deposits,Northern Carlin Trend,Nevada[J].Economic Geology,98(6):1 069~1 105.
Fu Shaohong,Gu Xuexiang,Wang Qian,et al.2004.The typomorphic characteristics of gold-bearing pyrites from Shuiyindong gold deposit,SW Guizhou[J].Acta Mineralogica Sinica,24(1):75~80(in Chinese).
Hu Wenxuan,Zhang Wenlan,Hu Shouxi,et al.2001.Determination of structural gold in Au-bearing arsenopyrite and its formation mechanism[J].Acta Geologica Sinica,75(3):410~418(in Chinese).
Hua Shuguang,Wang Lijuan,Jia Xiaofang,et al.2012.Occurrence and enrichment mechanism of gold in the Qiuling Carlin-Type gold deposit,Zhen'an County,Shanxi Province,China[J].Earth ScienceJournal of China University of Geosciences,37(5):989~1 002(in Chinese).
Huang Yong,Tang Juxing and Zhang Li.2014.Gold in the Xiongcun porphyry copper-gold deposit,Tibet:its distribution and significance[J].Acta Petrologica et Mineralogica,33(3):551~560(in Chinese).
Kesler S E,Chryssoulis S L and Simon G.2002.Gold in porphyry copper deposits:its abundance and fate[J].Ore Geology Reviews,21(1~2):103~124.
Kesler S E,Fortuna J,Ye Z J,et al.2003.Evaluation of the role of sulfidation in deposition of gold,screamer section of the Betze-Post Carlin-Type Deposit,Nevada[J].Economic Geology,98(6):1 137~1 157.
Li Jiuling,Zhang Guilan,Qi Feng,et al.1997.Experimental research on the migration regularity of Au in the“Fe-Au-Sb-S”System[J].Mineral Deposits,16(1):79~85(in Chinese).
Li Jiuling,Qi Feng,Xu Qingsheng,et al.2002.Ascertainment of chemically bound gold and its valence state in arsenopyrite and arsenian pyrite from Jinya Mine,Guangxi,China[J].Mineral Deposits,21(s1):1 160~1 163(in Chinese).
Li Zengsheng,Zhu Xiaoqing,Lu Huanzhang,et al.2013.Advances and current problems in the study of the occurrence of“Invisible Gold”in sulfides[J].Geological Science and Technology Information,33(3):81~86(in Chinese).
Liu Jianzhong,Xia Yong,Deng Yiming,et al.2007.Re-study on modes of gold occurrence in the Shuiyindong super-large-sized gold deposit[J].Guizhou Geology,24(3):165~169(in Chinese).
Ma Jianqin,Li Chaoyang and Wen Hanjie.1999.The status quo of research on the occurrence of Invisible Gold[J].Acta Mineralogica Sinica,19(3):335~342(in Chinese).
Reich M,Kesler S E,Utsunomiya S,et al.2005.Solubility of gold in arsenian pyrite[J].Geochimica et Cosmochimica Acta,69(11):2 781~2 796.
Rubin and Kyle.1997.Precious metal mineralogy in porphyry-,skarn-,and replacement-type ore deposits of the Ertsberg(Gunung Bijih)District,Irian Jaya,Indonesia[J].Economic Geology,92(5):535.
Sharp T G and Buseck P R.1993.The distribution of Ag and Sb in galena:inclusions versus solid solution[J].American Mineralogist,78(1~2):85~95.
Sillitoe R H.1979.Some thoughts on gold-rich porphyry copper deposits[J].Mineralium Deposita,14(2):161~174.
Simon G.1999.Geochemistarny and textures of gold-bearing arsenian pyrite,Twin Creeks,Nevada:implications for deposition of gold in Carlin-Type deposits[J].Economic Geology,94(3):405~421.
Simon G.2000.Gold in porphyry copper deposits:experimental determination of the distribution of gold in the Cu-Fe-S system at 400 to700℃[J].Economic Geology,95(2):259~270.
Simon G,Huang H,Pennerhahn J E,et al.1999.Oxidation state of gold and arsenic in gold-bearing arsenian pyrite[J].American Mineralogist,84(7~8):1 071~1 079.
Su Wenchao,Zhang Hongtao,Xia Bin,et al.2006.Visible gold in arsenian pyrite at the Shuiyindong Carlin-Type gold deposit,Guizhou,China[J].Acta Mineralogica Sinica,26(3):257~260(in Chinese).
Tomkins A G and Mavrogenes J A.2001.Redistribution of gold within arsenopyrite and lollingite during Pro-and retrograde metamorphism:application to timing of mineralization[J].Economic Geology,96(3):525~534.
Ulrich T,Gunther D and Heinrich C A.2002.The evolution of a porphyry Cu-Au deposit,Based on LA-ICP-MS analysis of fluid inclusions:Bajo de la Alumbrera,Argentina[J].Economic Geology,97(8):1 889~1 920.
Wang Kuiren,Zhou Youqin,Li Fanqing,et al.1992.Gold mine of Guangxi Microgranular gold occurrence of proton probe and scanning electron microscopy study[J].Chinese Science Bulletin,37(9):832~835(in Chinese).
Wang Meng.2017.A study on the geological and geochemical characteristics and genesis of the Chating Cu-Au ore deposit in Xuancheng City,Anhui Province[D].Hefei:Master Thesis of Hefei University of Technology,1~70(in Chinese).
Xie Yuling,Chen Wei,Li Lamei,et al.2010.Mineral assemblage,gold and silver occurrence and process properties of Nongruri Gold Deposit of Tibet[J].Journal of University of Science and Technology Beijing,32(5):543~551(in Chinese).
Zhang Zhenru and Yang Sixue.1986.The study of the fineness of gold[J].Geology and Prospecting,22(11):38~39(in Chinese).
陈懋弘,毛景文,陈振宇,等.2009.滇黔桂“金三角”卡林型金矿含砷黄铁矿和毒砂的矿物学研究[J].矿床地质,28(5):539~557.
陈光远,绍伟,孙岱生.1989.胶东金矿成因矿物学与找矿[M].重庆:重庆出版社,1~452.
付绍洪,顾雪祥,王乾,等.2004.黔西南水银洞金矿床载金黄铁矿标型特征[J].矿物学报,24(1):75~80.
胡文,张文兰,胡受奚,等.2001.含金毒砂中晶格金的确定及其形成机理研究[J].地质学报,75(3):410~418.
华曙光,王力娟,贾晓芳,等.2012.陕西镇安丘岭卡林型金矿金的赋存状态和富集机理[J].地球科学---中国地质大学学报,37(5):989~1 002.
黄勇,唐菊兴,张丽.2014.西藏雄村斑岩铜金矿床金的赋存状态及其意义[J].岩石矿物学杂志,33(3):551~560.
李九玲,张桂兰,亓锋,等.1997.“Fe-Au-Sb-S”体系中金迁移规律的实验研究[J].矿床地质,16(1):79~85.
李九玲,亓锋,徐庆生,等.2002.广西金牙金矿毒砂和黄铁矿中晶格金的确认及其价态研究[J].矿床地质,21(s1):1 160~1 163.
李胜荣,陈光远,邵伟,等.1996.胶东乳山金矿田成因矿物学[M].北京:地质出版社,1~116.
李增胜,朱笑青,卢焕章,等.2013.硫化物中“不可见金”的赋存状态研究进展[J].地质科技情报,33(3):81~86.
刘建中,夏勇,邓一明,等.2007.贵州水银洞超大型金矿床金的赋存状态再研究[J].贵州地质,24(3):165~169.
马建秦,李朝阳,温汉捷.1999.不可见金赋存状态研究现状[J].矿物学报,19(3):335~342.
苏文超,张弘弢,夏斌,等.2006.贵州水银洞卡林型金矿床首次发现大量次显微-显微可见自然金颗粒[J].矿物学报,26(3):257~260.
王奎仁,周有勤,李凡庆,等.1992.广西金牙金矿微细粒金赋存状态的质子探针和扫描电镜研究[J].科学通报,37(9):832~835.
王蒙.2017.安徽宣城茶亭铜金矿床地质和地球化学特征及成因研究[D].合肥:合肥工业大学硕士论文,1~70.
谢玉玲,陈伟,李腊梅,等.2010.西藏弄如日金矿矿石矿物组成、金银赋存状态及工艺特性[J].北京科技大学学报,32(5):543~551.
张振儒,杨思学.1986.金的成色研究[J].地质与勘探,22(11):38~39.