小秦岭金矿区花岗岩磷灰石-锆石对岩浆氧逸度的约束
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摘要
小秦岭金矿区华山和文峪花岗岩体形成年龄与金成矿年龄相近,已知金矿多集中在文峪岩体周围,比较两岩体岩浆氧逸度的异同有利于判断其对金成矿影响的异同。本文利用两岩体磷灰石中锰离子价态和锆石钛含量,对岩浆的氧逸度进行了约束。计算表明,华山岩体成岩氧逸度lgf(O_2)在-9.3～-5.1之间,而文峪岩体成岩氧逸度在-8.5～-6.1之间,均属大于HM缓冲线的高氧逸度环境。Au在还原状态易呈自然金而沉淀,氧化状态时易以Au~+或Au~(3+)迁移。故华山和文峪岩体的岩浆都不能对金形成地球化学障而使之分散。
Formation ages of the Huashan and Wenyu granitoid plutons are similar to those of gold deposits in the Xiaoqinling gold district. It is known that most gold deposits are clustered around the Wenyu pluton. To compare similarities and differences of magmatic properties of the Huashan and Wenyu two plutons will be helpful to judge their influences on the gold mineralization. In this paper, the oxygen fugacity of magma has been constrained using valence states of manganese ions in apatites and titanium contents in zircons of the two plutons. The calculation results show that magmatic oxygen fugacities of the Huashan pluton change from-9.3 and-5.1, while those of the Wenyu pluton range from-8.5 and-6.1. They are all plotted above the HM Buffer line in a field of high oxygen fugacity. It is believed that Au prefers to migrate in oxidized states of Au~+ or Au~(3+) and precipitate in reduced state of native gold. Therefore, the magma of the Huashan and Wenyu granitic plutons had no chance to form a geochemical barrier to precipitate gold but is favorable to let gold migrate to favorable structural spaces in the periphery.
Formation ages of the Huashan and Wenyu granitoid plutons are similar to those of gold deposits in the Xiaoqinling gold district. It is known that most gold deposits are clustered around the Wenyu pluton. To compare similarities and differences of magmatic properties of the Huashan and Wenyu two plutons will be helpful to judge their influences on the gold mineralization. In this paper, the oxygen fugacity of magma has been constrained using valence states of manganese ions in apatites and titanium contents in zircons of the two plutons. The calculation results show that magmatic oxygen fugacities of the Huashan pluton change from-9.3 and-5.1, while those of the Wenyu pluton range from-8.5 and-6.1. They are all plotted above the HM Buffer line in a field of high oxygen fugacity. It is believed that Au prefers to migrate in oxidized states of Au~+ or Au~(3+) and precipitate in reduced state of native gold. Therefore, the magma of the Huashan and Wenyu granitic plutons had no chance to form a geochemical barrier to precipitate gold but is favorable to let gold migrate to favorable structural spaces in the periphery.
引文
[1]周振菊,蒋少涌,秦艳,等.小秦岭文峪金矿床流体包裹体研究及矿床成因[J].岩石学报, 2011, 27(12):3787-3799.
[2]黎世美,翟伦全,苏振邦,等.小秦岭金矿地质和成矿预测[M].北京:地质出版社, 1996.
[3]聂凤军,江思宏,赵月明.小秦岭地区文峪和东闯石英脉型金矿床铅及硫同位素研究[J].矿床地质, 2001(2):163-173.
[4]李乃志,于在平,崔海峰,等.变质核杂岩特征及小秦岭地区变质杂岩成因讨论[J].西北大学学报(自然科学版), 2006, 36:793-798.
[5]王团华,毛景文,王彦斌.小秦岭一熊耳山地区岩墙锆石SHRIMP年代学研究—秦岭造山带岩石圈拆沉的证据[J].岩石学报, 2008, 24(6):1273-1287.
[6]徐启东,钟增球,周汉文,等.小秦岭地区金矿化与花岗岩浆活动的关系-流体标型特征提供的依据[J].大地构造与成矿学, 1998, 22(1):35-44.
[7]徐启东,钟增球,周汉文,等.豫西小秦岭金矿区的一组40Ar-39Ar定年数据[J].地质论评, 1998, 44(3):323-327.
[8]冯建之.小秦岭金矿床作用及成矿物质来源[J].现代地质, 2010, 24(1):11-17.
[9]王建其,朱赖民,郭波,等.华北陆块南缘华山、老牛山及合峪花岗岩体Sr-Nd,Pb同位素组成特征及其地质意义[J].矿物岩石, 2015, 35(1):63-72.
[10]温子豪,李胜荣,袁茂文,等.小秦岭华山和文峪岩体成金潜力异同：来自锆石群形态标型的证据[J].地球科学与环境学报, 2018, 40(5):535-545.
[11]余心起,刘俊来,张德会,等.小秦岭文峪花岗岩山体的隆升时代和幅度[J].科学通报, 2013, 58:3416-3428.
[12] Miles AJ, Graham CM, Hawkesworth CJ, et al. Apatite:A new redox proxy for silcic magmas?[J]. Geochimica et Cosmochimica Acta, 2014, 132:101-109.
[13]周珣若.氧逸度的估算及其在岩矿方面的应用[J].岩矿地化研究, 1981, 11:38-46.
[14]张聚全,李胜荣,卢静.中酸性侵入岩的氧逸度计算[J].矿物学报, 2018, 38(1):1-14.
[15]韩丽,黄小龙,李洁,等.江西大湖塘钨矿花岗岩的磷灰石特征及其氧逸度变化指示[J].岩石学报, 2016, 32(3):746-758.
[16]周瑶琪,史冰洁,李素,等.副矿物地球化学研究进展[J].中国石油大学学报(自然科学版), 2013, 37(4):59-70.
[17] Li Sheng-Rong, Santosh M. Metallogeny and craton destruction:records from the North China Craton[J]. Ore Geology Review, 2014, 56:376-414.
[18] Li Sheng-Rong, Santosh M. Geodynamics of heterogeneous gold mineralization in the North China Craton and its relationship to lithospheric destruction[J]. Gondwana Research, 2017, 50:267-292.
[19] Li Lin, Santosh M, Li Sheng-Rong. The"Jiaodong type"gold deposits:Characteristics, origin and prospecting[J]. Ore Geology Reviews, 2015, 65,589-611.
[20] Li Lin, Li Sheng-Rong, Santosh M., et al. Dyke swarms and their role in the genesis of world-class gold deposits:insights from the Jiaodong peninsula[J]. China. Journal of Asian Earth Sciences, 2016, 130, 2-22.
[21]毛景文,谢桂青,张作衡,等.中国北方中生代大规模成矿作用的期次及其地球动力学背景[J].岩石学报, 2005, 21(1):169-188.
[22]夏学慧.北方若干内生磷矿磷灰石的标型特征及其研究意义[M].化工部化学矿产地质研究院, 1985.
[23] Stormer J C, Pierson M L, Tacker R C. Variation of F and Cl X-ray intensity due to anisotropic diffussion in apatite during electron microprobe analysis[J]. American Mineralogist, 1993, 78(2/3):641-648.
[24]王蝶,毕献武,周汀,等.金沙江-红河富碱侵入岩磷灰石挥发分组成特征及其地质意义[J].矿物学报, 2013, 33(2):231-238.
[25]徐登科.矿物化学式计算方法[M].北京:地质出版社, 1977.
[26] Watson E B, Wark D A, Thomas J B. Crystallization thermometers for zircon and rutile Contrib[J]. Mineral Petrol, 2006, 151:413-433.
[27] Pasero M., Kampf AR, Ferraris C, et al. Nomenclature of the apatite supergroup minerals[J]. EUR J Mineral, 2010, 22:163-179.
[28]李胜荣,许虹.结晶学与矿物学[M].北京:地质出版社, 2008.
[29] Hughes JM, Rakovan J. The crystal structure of apatite, Ca5(PO4)3(F,OH,Cl)[J]. Reviews in Mineralogy&Geochemistry, 2002, 48(1):1-12.
[30]刘羽,彭明生.磷灰石结构替换的研究进展[J].岩石矿物学杂志, 2003, 22(4):413-415.
[31] Aoki K, Ishiwaka K, Kanisawa S. Fluorine geochemistry of basaltic rocks from continental and oceanic regions and petrogenetic application[J].Contributions to Mineralogy and Petrology, 1981, 78:53-59.
[32] Gundmundur E, Sigvaldson E, Oskarsson N. Fluorine in basalts from Iceland[J]. Contributions to Mineralogy and Petrology, 1986, 94:263-271.
[33] Smith J V, Delaney J S, Hervig R L, et al. Storage of F and Cl in upper mantle:Geochemical implications[J]. Lithos, 1981, 14:132-147.
[34] Vukadinovic D, Edgar A D. Phase relations in the phlogopite-apatite system at 20 kbar:Implications for the role of fluorine in mantle melting[J].Contributions to Mineralogy and Petrology, 1993, 114:254-274.
[35]刘羽.几种成因类型磷灰石的矿物学研究[J].武汉化工学院学报, 1992, 14(2):16-21.
[36] Pan Y, Fleet M E. Compositions of the apatite-group minerals:Substitution mechanisms and controlling factors[J]. Reviews in Mineralogy and Geochemistry, 2012, 48(1):13-49.
[37] Hughes J M, Ertl A, Bernhardt H J, et al. Mnrich fluorapatite from Austria:Crystal structure, chemical analysis and spectroscopic investigations[J].American Mineralogist, 2004, 89(4):629-632.
[38] Sha L K, Chappell B W. Apatite chemical composition, determined by electron microprobe and laser-ablation inductively coupled plasma mass spectrometry,as a probe into granite petrogenesis[J]. Geochimica et Cosmochimica Acta, 1999, 63(22):3861-3881.
[39] Frost B R. Introduction to oxygen fugacity and its peteoligic importance[J]. Lindsley DH. Oxide Minerals:Petrologic and Magnetic Significance.Review in Mineralogy, 1991, 25:1-9.
[2]黎世美,翟伦全,苏振邦,等.小秦岭金矿地质和成矿预测[M].北京:地质出版社, 1996.
[3]聂凤军,江思宏,赵月明.小秦岭地区文峪和东闯石英脉型金矿床铅及硫同位素研究[J].矿床地质, 2001(2):163-173.
[4]李乃志,于在平,崔海峰,等.变质核杂岩特征及小秦岭地区变质杂岩成因讨论[J].西北大学学报(自然科学版), 2006, 36:793-798.
[5]王团华,毛景文,王彦斌.小秦岭一熊耳山地区岩墙锆石SHRIMP年代学研究—秦岭造山带岩石圈拆沉的证据[J].岩石学报, 2008, 24(6):1273-1287.
[6]徐启东,钟增球,周汉文,等.小秦岭地区金矿化与花岗岩浆活动的关系-流体标型特征提供的依据[J].大地构造与成矿学, 1998, 22(1):35-44.
[7]徐启东,钟增球,周汉文,等.豫西小秦岭金矿区的一组40Ar-39Ar定年数据[J].地质论评, 1998, 44(3):323-327.
[8]冯建之.小秦岭金矿床作用及成矿物质来源[J].现代地质, 2010, 24(1):11-17.
[9]王建其,朱赖民,郭波,等.华北陆块南缘华山、老牛山及合峪花岗岩体Sr-Nd,Pb同位素组成特征及其地质意义[J].矿物岩石, 2015, 35(1):63-72.
[10]温子豪,李胜荣,袁茂文,等.小秦岭华山和文峪岩体成金潜力异同：来自锆石群形态标型的证据[J].地球科学与环境学报, 2018, 40(5):535-545.
[11]余心起,刘俊来,张德会,等.小秦岭文峪花岗岩山体的隆升时代和幅度[J].科学通报, 2013, 58:3416-3428.
[12] Miles AJ, Graham CM, Hawkesworth CJ, et al. Apatite:A new redox proxy for silcic magmas?[J]. Geochimica et Cosmochimica Acta, 2014, 132:101-109.
[13]周珣若.氧逸度的估算及其在岩矿方面的应用[J].岩矿地化研究, 1981, 11:38-46.
[14]张聚全,李胜荣,卢静.中酸性侵入岩的氧逸度计算[J].矿物学报, 2018, 38(1):1-14.
[15]韩丽,黄小龙,李洁,等.江西大湖塘钨矿花岗岩的磷灰石特征及其氧逸度变化指示[J].岩石学报, 2016, 32(3):746-758.
[16]周瑶琪,史冰洁,李素,等.副矿物地球化学研究进展[J].中国石油大学学报(自然科学版), 2013, 37(4):59-70.
[17] Li Sheng-Rong, Santosh M. Metallogeny and craton destruction:records from the North China Craton[J]. Ore Geology Review, 2014, 56:376-414.
[18] Li Sheng-Rong, Santosh M. Geodynamics of heterogeneous gold mineralization in the North China Craton and its relationship to lithospheric destruction[J]. Gondwana Research, 2017, 50:267-292.
[19] Li Lin, Santosh M, Li Sheng-Rong. The"Jiaodong type"gold deposits:Characteristics, origin and prospecting[J]. Ore Geology Reviews, 2015, 65,589-611.
[20] Li Lin, Li Sheng-Rong, Santosh M., et al. Dyke swarms and their role in the genesis of world-class gold deposits:insights from the Jiaodong peninsula[J]. China. Journal of Asian Earth Sciences, 2016, 130, 2-22.
[21]毛景文,谢桂青,张作衡,等.中国北方中生代大规模成矿作用的期次及其地球动力学背景[J].岩石学报, 2005, 21(1):169-188.
[22]夏学慧.北方若干内生磷矿磷灰石的标型特征及其研究意义[M].化工部化学矿产地质研究院, 1985.
[23] Stormer J C, Pierson M L, Tacker R C. Variation of F and Cl X-ray intensity due to anisotropic diffussion in apatite during electron microprobe analysis[J]. American Mineralogist, 1993, 78(2/3):641-648.
[24]王蝶,毕献武,周汀,等.金沙江-红河富碱侵入岩磷灰石挥发分组成特征及其地质意义[J].矿物学报, 2013, 33(2):231-238.
[25]徐登科.矿物化学式计算方法[M].北京:地质出版社, 1977.
[26] Watson E B, Wark D A, Thomas J B. Crystallization thermometers for zircon and rutile Contrib[J]. Mineral Petrol, 2006, 151:413-433.
[27] Pasero M., Kampf AR, Ferraris C, et al. Nomenclature of the apatite supergroup minerals[J]. EUR J Mineral, 2010, 22:163-179.
[28]李胜荣,许虹.结晶学与矿物学[M].北京:地质出版社, 2008.
[29] Hughes JM, Rakovan J. The crystal structure of apatite, Ca5(PO4)3(F,OH,Cl)[J]. Reviews in Mineralogy&Geochemistry, 2002, 48(1):1-12.
[30]刘羽,彭明生.磷灰石结构替换的研究进展[J].岩石矿物学杂志, 2003, 22(4):413-415.
[31] Aoki K, Ishiwaka K, Kanisawa S. Fluorine geochemistry of basaltic rocks from continental and oceanic regions and petrogenetic application[J].Contributions to Mineralogy and Petrology, 1981, 78:53-59.
[32] Gundmundur E, Sigvaldson E, Oskarsson N. Fluorine in basalts from Iceland[J]. Contributions to Mineralogy and Petrology, 1986, 94:263-271.
[33] Smith J V, Delaney J S, Hervig R L, et al. Storage of F and Cl in upper mantle:Geochemical implications[J]. Lithos, 1981, 14:132-147.
[34] Vukadinovic D, Edgar A D. Phase relations in the phlogopite-apatite system at 20 kbar:Implications for the role of fluorine in mantle melting[J].Contributions to Mineralogy and Petrology, 1993, 114:254-274.
[35]刘羽.几种成因类型磷灰石的矿物学研究[J].武汉化工学院学报, 1992, 14(2):16-21.
[36] Pan Y, Fleet M E. Compositions of the apatite-group minerals:Substitution mechanisms and controlling factors[J]. Reviews in Mineralogy and Geochemistry, 2012, 48(1):13-49.
[37] Hughes J M, Ertl A, Bernhardt H J, et al. Mnrich fluorapatite from Austria:Crystal structure, chemical analysis and spectroscopic investigations[J].American Mineralogist, 2004, 89(4):629-632.
[38] Sha L K, Chappell B W. Apatite chemical composition, determined by electron microprobe and laser-ablation inductively coupled plasma mass spectrometry,as a probe into granite petrogenesis[J]. Geochimica et Cosmochimica Acta, 1999, 63(22):3861-3881.
[39] Frost B R. Introduction to oxygen fugacity and its peteoligic importance[J]. Lindsley DH. Oxide Minerals:Petrologic and Magnetic Significance.Review in Mineralogy, 1991, 25:1-9.