辽宁岫岩河磨玉岩石地球化学组成及锆石U-Pb定年研究
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摘要
河磨玉是产于辽宁省岫岩县细玉沟沟谷及白沙河河谷底部和两岸阶地的和田玉,目前仅依据产出位置判断河磨玉来源于细玉沟沟头的原生和田玉矿床,但河磨玉的矿物组成、地球化学特征、年龄等并不清楚,与原生和田玉是否一致有待深入研究。本文主要通过电子探针成分分析、全岩主微量分析、氢氧同位素分析、锆石SHRIMP U-Pb定年等测试方法对河磨玉的矿物组成、地球化学特征及年龄进行研究,确定河磨玉与老玉是否为相同成因。结果表明:①河磨玉中主要矿物为透闪石、阳起石,次要矿物为透辉石、磷灰石、绿泥石、绿帘石、石英、榍石、锆石、磁铁矿、菱锌矿等。②河磨玉的成因类型为大理岩型。河磨玉稀土总量低,相对富集轻稀土,普遍显示Eu正异常。③河磨玉中透闪石δ18O值为8. 00‰～10. 60‰,δD值为-94. 95‰～-75. 20‰,成矿流体中的水主要为岩浆水。④河磨玉中的岩浆锆石U-Pb年龄为220. 8±7. 6Ma(n=4,MSWD=2. 3),代表河磨玉成玉年龄的上限。本文提出河磨玉的稀土分配特征、氢氧同位素组成、成矿流体来源及形成年龄均与原生和田玉不一致,河磨玉并非来源于细玉沟沟头的原生和田玉。
BACKGROUND: The Xiuyan placer nephrite is located in the Xiyu gully,Baisha river valley and terrace,located in Xiuyan,Liaoning Province. Currently,the primary nephrite in the Xiyu gully is regarded as the Xiuyan placer nephrite's primary deposit according to location. However,the mineral composition,geochemical characteristics and age of the placer nephrite is unknown; whether they are consistent with primary nephrite needs to be studied further.OBJECTIVES: To confirm whether the Xiuyan placer nephrite is from primary nephrite by investigating the mineral composition,geochemical characteristics and age of the Xiuyan placer nephrite.METHODS: Electron microprobe analysis( EMPA),inductively coupled plasma-mass spectrometry( ICP-MS),X-ray fluorescence spectrometry( XRF),stable isotope mass spectrometry and zircon SHRIMP U-Pb dating were employed.RESULTS: Primary minerals of the Xiuyan placer nephrite were tremolite,actinolite,whereas secondary minerals were diopside,apatite,chlorite,epidote,quartz,titanite,zircon,magnetite,and smithsonite. The Xiuyan placer nephrite was dolomite-related nephrite. Its total rare earth element( REE) was low with LREE enrichment and positive Eu anomaly. The δ18 O and δD isotope compositions of nephrite were from 8. 00‰ to 10. 60‰ and from-94. 75‰ to-75. 20‰,respectively. Water in ore-forming fluids was mainly magmatic water. Zircon U-Pb age of the placer nephrite was 220. 8 ± 7. 6 Ma,which suggested that the placer nephrite formed after this time.CONCLUSIONS: The Xiuyan placer nephrite is different from primary nephrite in bulk-rock REE pattern,hydrogen and oxygen isotope compositions,and source of ore-forming fluids and age,which may indicate that the placer nephrite is not derived from the original nephrite in the Xiyu gully.
BACKGROUND: The Xiuyan placer nephrite is located in the Xiyu gully,Baisha river valley and terrace,located in Xiuyan,Liaoning Province. Currently,the primary nephrite in the Xiyu gully is regarded as the Xiuyan placer nephrite's primary deposit according to location. However,the mineral composition,geochemical characteristics and age of the placer nephrite is unknown; whether they are consistent with primary nephrite needs to be studied further.OBJECTIVES: To confirm whether the Xiuyan placer nephrite is from primary nephrite by investigating the mineral composition,geochemical characteristics and age of the Xiuyan placer nephrite.METHODS: Electron microprobe analysis( EMPA),inductively coupled plasma-mass spectrometry( ICP-MS),X-ray fluorescence spectrometry( XRF),stable isotope mass spectrometry and zircon SHRIMP U-Pb dating were employed.RESULTS: Primary minerals of the Xiuyan placer nephrite were tremolite,actinolite,whereas secondary minerals were diopside,apatite,chlorite,epidote,quartz,titanite,zircon,magnetite,and smithsonite. The Xiuyan placer nephrite was dolomite-related nephrite. Its total rare earth element( REE) was low with LREE enrichment and positive Eu anomaly. The δ18 O and δD isotope compositions of nephrite were from 8. 00‰ to 10. 60‰ and from-94. 75‰ to-75. 20‰,respectively. Water in ore-forming fluids was mainly magmatic water. Zircon U-Pb age of the placer nephrite was 220. 8 ± 7. 6 Ma,which suggested that the placer nephrite formed after this time.CONCLUSIONS: The Xiuyan placer nephrite is different from primary nephrite in bulk-rock REE pattern,hydrogen and oxygen isotope compositions,and source of ore-forming fluids and age,which may indicate that the placer nephrite is not derived from the original nephrite in the Xiyu gully.
引文
[1] Harlow G E,Sorensen S S. Jade(nephrite and jadeitite)and serpentinite:Metasomatic connections[J].International Geology Review,2005,47(2):113-146.
[2] Liu Y,Zhang R Q,Zhang Z Y,et al. Mineral inclusions and SHRIMP U-Pb dating of zircons from the Alamas nephrite and granodiorite:Implications for the genesis of a magnesian skarn deposit[J]. Lithos,2015,212-215:128-144.
[3] Liu Y,Zhang R Q,Abuduwayiti M,et al. SHRIMP UPb zircon ages,mineral compositions and geochemistry of placer nephrite in the Yurungkash and Karakash River deposits,West Kunlun,Xinjiang,Northwest China:Implication for a magnesium skarn[J]. Ore Geology Reviews,2016,72:699-727.
[4] Yui T F,Kwon S T. Origin of a dolomite-related jade deposit at Chuncheon,Korea[J]. Economic Geology,2002,97(3):593-601.
[5] Liu Y,Deng J,Shi G H,et al. Geochemistry and petrology of nephrite from Alamas,Xinjiang,NW China[J].Journal of Asian Earth Sciences,2011,42(3):440-451.
[6] Liu Y,Deng J,Shi G H,et al. Geochemistry and petrogenesis of placer nephrite from Hetian,Xinjiang,Northwest China[J]. Ore Geology Reviews,2011,41(1):122-132.
[7]刘喜锋，张红清，刘琰，等．世界范围内代表性碧玉的矿物特征和成因研究[J]．岩矿测试，2018,37(5):479-489.Liu X F,Zhang H Q,Liu Y,et al. Mineralogical characteristics and genesis of green nephrite from the world[J]. Rock and Mineral Analysis,2018,37(5):479-489.
[8] Grapes R H,Yun S T. Geochemistry of a New Zeland nephrite weathering rind[J]. New Zealand Journal of Geology and Geophysics,2010,53:413-426.
[9] Kostov R I,Protochristov C,Stoyanov C,et al. MicroPIXE geochemical fingerprinting of nephrite neolithic artifacts from South-West Bulgaria[J]. Geoarchaeology:An International Journal,2012,27:457-469.
[10] Siqin B,Qian R,Zhuo S,et al. Glow discharge mass spectrometry studies on nephrite minerals formed by different metal logenic mechanisms and geological environments[J]. International Journal of Mass Spectrometry,2012,309:206-211.
[11] Barnes G L. Understanding Chinese jade in a world context[J]. Journal of the British Academic,2018,6:1-63.
[12]王时麒，赵朝洪，于洸，等．中国岫岩玉[M]．北京:科学出版社，2007.Wang S Q,Zhao C H,Yu G,et al. Xiuyan Jades in China[M]. Beijing:Science Press,2007.
[13]王时麒，董佩信．岫岩玉的种类、矿床地质特征及成因[J]．地质与资源，2011,20(5):321-331.Wang S Q, Dong P X. Classification, geologic characteristics and origin of the jade from Xiuyan,Liaoning Province,China[J]. Geology and Resources,2011,20(5):321-331.
[14]丘志力，江启云，落汗，等．辽宁岫岩河磨玉和老玉(闪石玉)中石墨包体的拉曼光谱及其应用[J]．光谱学与光谱分析，2010,30(11):2985-2988.Qiu Z L,Jiang Q Y,Luo H,et al. Raman spectra and its application of graphite enclaves in nephrite-jades in Xiuyan,Liaoning[J]. Spectroscopy and Spectral Analysis,2010,30(11):2985-2988.
[15] Clayton R N,Mayeda T K. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis[J]. Geochimica et Cosmochimica Acta,1963,27(1):43-52.
[16] Friedman I. Deuterium content of natural waters and other substances[J]. Geochimica et Cosmochimica Acta,1953,4(1-2):89-103.
[17] Black L P,Kamo S L,Allen C M,et al. TEMORA 1:A new zircon standard for Phanerozoic U-Pb geochronology[J]. Chemical Geology,2003,200(1):155-170.
[18] Nasdala L,Hofmeister W,Norberg N,et al. Zircon M257—A homogeneous natural reference material for the ion microprobe U-Pb analysis of zircon[J].Geostandards and Geoanalytical Research,2008,32(3):247-265.
[19] Black L P,Kamo S L,Williams I S,et al. The application of SHRIMP to Phanerozoic geochronology:A critical appraisal of four zircon standards[J]. Chemical Geology,2003,200:171-188.
[20] Ludwig K R. SQUID 1. 02,A User’S Manual[M]. Berkeley Geochronology Center Special Publication No. 2.2455 Ridge Road,Berkeley,CA 94709,USA,2002.
[21] Stacey J S,Kramers J D. Approximation of terrestrial lead isotope evolution by a two-stage model[J]. Earth&Planetary Science Letters,1975,26:207-221.
[22] Adamo I,Bocchio R. Nephrite jade from Val Malenco,Italy:Review and update[J]. Gems and Gemology,2013,49:98-106.
[23] Yui T F,Yeh H W,Wang L C. Stable isotope studies of nephrite deposits from Fengtien, Taiwan[J].Geochimica et Cosmochimica Acta,1988,52:593-602.
[24]郑永飞，徐宝龙，周根陶．矿物稳定同位素地球化学研究[J]．地学前缘，2000,7(2):299-320.Zheng Y F,Xu B L,Zhou G T. Geochemical studies of stable isotopes in minerals[J]. Earth Science Frontiers,2000,7(2):299-320.
[25] Graham C H,Harmon R S,Sheppard S M F. Experimental hydrogen isotope studies:Hydrogen isotope exchange between amphilbole and water[J]. American Mineralogist,1984,69:128-138.
[26] Taylor Jr H P. Oxygen and Hydrogen Isotope Relationships in Hydrothermal Mineral Deposits[C]//Barnes H L. Geochemistry of Hydrothermal Ore Deposits(3rd Edition). New York:Wiley-Interscience,1997:229-302.
[27] Gil G,Barnes J D,Boschi C,et al. Nephrite from Zoty Stok(Sudetes,SW Poland):Petrological,geochemical and isotopic evidence for a dolomite-related origin[J].The Canadian Mineralogist,2015,53(3):533-556.
[28]李长民．锆石成因矿物学与锆石微区定年综述[J]．地质调查与研究，2009,33(3):161-174.Li C M. A review on the minerageny and situ microanalytical dating techniques of zircons[J].Geological Survey and Research,2009,33(3):161-174.
[29]李大中，于士祥，王泽．辽宁岫岩地区岫玉成矿规律探讨[J]．地质找矿论丛，2013,28(2):249-255.Li D Z,Yu S X,Wang Z. Discussion on the jadeforming regularity of Xiuyan jade in Xiuyan area,Liaoning Province[J]. Contributions to Geology and Mineral Resources Research,2013,28(2):249-255.
[30]刘喜锋，刘琰，李自静，等．新疆皮山镁质矽卡岩矿床(含糖玉)成因及锆石SHRIMP U-Pb定年[J]．岩石矿物学杂志，2017,36(2):259-273.Liu X F,Liu Y,Li Z J,et al. The genesis of Mg-skarn deposit(bearing brown nephrite)and its Ar-Ar dating of phlogopite and SHRIMP U-Pb dating of zircon,Pishan,Xinjiang[J]. Acta Petrologica et Mineralogica,2017,36(2):259-273.
[31]张勇，魏华，陆太进，等．新疆奥米夏和田玉矿床成因及锆石LA-ICP-MS定年研究[J]．岩矿测试，2018,37(6):695-704.Zhang Y,Wei H,Lu T J,et al. The genesis and LA-ICP-MS zircon ages of the Omixia nephrite deposit,Xinjiang,China[J]. Rock and Mineral Analysis,2018,37(6):695-704.
[32]贾玉衡，刘喜锋，刘琰，等．新疆且末碧玉矿的成因研究[J]．岩石矿物学杂志，2018,37(5):824-838.Jia Y H,Liu X F,Liu Y,et al. Petrogenesis of the serpentinite-related nephrite deposit in Qiemo County,Xinjiang[J]. Acta Petrologica et Mineralogica,2018,37(5):824-838.
[2] Liu Y,Zhang R Q,Zhang Z Y,et al. Mineral inclusions and SHRIMP U-Pb dating of zircons from the Alamas nephrite and granodiorite:Implications for the genesis of a magnesian skarn deposit[J]. Lithos,2015,212-215:128-144.
[3] Liu Y,Zhang R Q,Abuduwayiti M,et al. SHRIMP UPb zircon ages,mineral compositions and geochemistry of placer nephrite in the Yurungkash and Karakash River deposits,West Kunlun,Xinjiang,Northwest China:Implication for a magnesium skarn[J]. Ore Geology Reviews,2016,72:699-727.
[4] Yui T F,Kwon S T. Origin of a dolomite-related jade deposit at Chuncheon,Korea[J]. Economic Geology,2002,97(3):593-601.
[5] Liu Y,Deng J,Shi G H,et al. Geochemistry and petrology of nephrite from Alamas,Xinjiang,NW China[J].Journal of Asian Earth Sciences,2011,42(3):440-451.
[6] Liu Y,Deng J,Shi G H,et al. Geochemistry and petrogenesis of placer nephrite from Hetian,Xinjiang,Northwest China[J]. Ore Geology Reviews,2011,41(1):122-132.
[7]刘喜锋，张红清，刘琰，等．世界范围内代表性碧玉的矿物特征和成因研究[J]．岩矿测试，2018,37(5):479-489.Liu X F,Zhang H Q,Liu Y,et al. Mineralogical characteristics and genesis of green nephrite from the world[J]. Rock and Mineral Analysis,2018,37(5):479-489.
[8] Grapes R H,Yun S T. Geochemistry of a New Zeland nephrite weathering rind[J]. New Zealand Journal of Geology and Geophysics,2010,53:413-426.
[9] Kostov R I,Protochristov C,Stoyanov C,et al. MicroPIXE geochemical fingerprinting of nephrite neolithic artifacts from South-West Bulgaria[J]. Geoarchaeology:An International Journal,2012,27:457-469.
[10] Siqin B,Qian R,Zhuo S,et al. Glow discharge mass spectrometry studies on nephrite minerals formed by different metal logenic mechanisms and geological environments[J]. International Journal of Mass Spectrometry,2012,309:206-211.
[11] Barnes G L. Understanding Chinese jade in a world context[J]. Journal of the British Academic,2018,6:1-63.
[12]王时麒，赵朝洪，于洸，等．中国岫岩玉[M]．北京:科学出版社，2007.Wang S Q,Zhao C H,Yu G,et al. Xiuyan Jades in China[M]. Beijing:Science Press,2007.
[13]王时麒，董佩信．岫岩玉的种类、矿床地质特征及成因[J]．地质与资源，2011,20(5):321-331.Wang S Q, Dong P X. Classification, geologic characteristics and origin of the jade from Xiuyan,Liaoning Province,China[J]. Geology and Resources,2011,20(5):321-331.
[14]丘志力，江启云，落汗，等．辽宁岫岩河磨玉和老玉(闪石玉)中石墨包体的拉曼光谱及其应用[J]．光谱学与光谱分析，2010,30(11):2985-2988.Qiu Z L,Jiang Q Y,Luo H,et al. Raman spectra and its application of graphite enclaves in nephrite-jades in Xiuyan,Liaoning[J]. Spectroscopy and Spectral Analysis,2010,30(11):2985-2988.
[15] Clayton R N,Mayeda T K. The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis[J]. Geochimica et Cosmochimica Acta,1963,27(1):43-52.
[16] Friedman I. Deuterium content of natural waters and other substances[J]. Geochimica et Cosmochimica Acta,1953,4(1-2):89-103.
[17] Black L P,Kamo S L,Allen C M,et al. TEMORA 1:A new zircon standard for Phanerozoic U-Pb geochronology[J]. Chemical Geology,2003,200(1):155-170.
[18] Nasdala L,Hofmeister W,Norberg N,et al. Zircon M257—A homogeneous natural reference material for the ion microprobe U-Pb analysis of zircon[J].Geostandards and Geoanalytical Research,2008,32(3):247-265.
[19] Black L P,Kamo S L,Williams I S,et al. The application of SHRIMP to Phanerozoic geochronology:A critical appraisal of four zircon standards[J]. Chemical Geology,2003,200:171-188.
[20] Ludwig K R. SQUID 1. 02,A User’S Manual[M]. Berkeley Geochronology Center Special Publication No. 2.2455 Ridge Road,Berkeley,CA 94709,USA,2002.
[21] Stacey J S,Kramers J D. Approximation of terrestrial lead isotope evolution by a two-stage model[J]. Earth&Planetary Science Letters,1975,26:207-221.
[22] Adamo I,Bocchio R. Nephrite jade from Val Malenco,Italy:Review and update[J]. Gems and Gemology,2013,49:98-106.
[23] Yui T F,Yeh H W,Wang L C. Stable isotope studies of nephrite deposits from Fengtien, Taiwan[J].Geochimica et Cosmochimica Acta,1988,52:593-602.
[24]郑永飞，徐宝龙，周根陶．矿物稳定同位素地球化学研究[J]．地学前缘，2000,7(2):299-320.Zheng Y F,Xu B L,Zhou G T. Geochemical studies of stable isotopes in minerals[J]. Earth Science Frontiers,2000,7(2):299-320.
[25] Graham C H,Harmon R S,Sheppard S M F. Experimental hydrogen isotope studies:Hydrogen isotope exchange between amphilbole and water[J]. American Mineralogist,1984,69:128-138.
[26] Taylor Jr H P. Oxygen and Hydrogen Isotope Relationships in Hydrothermal Mineral Deposits[C]//Barnes H L. Geochemistry of Hydrothermal Ore Deposits(3rd Edition). New York:Wiley-Interscience,1997:229-302.
[27] Gil G,Barnes J D,Boschi C,et al. Nephrite from Zoty Stok(Sudetes,SW Poland):Petrological,geochemical and isotopic evidence for a dolomite-related origin[J].The Canadian Mineralogist,2015,53(3):533-556.
[28]李长民．锆石成因矿物学与锆石微区定年综述[J]．地质调查与研究，2009,33(3):161-174.Li C M. A review on the minerageny and situ microanalytical dating techniques of zircons[J].Geological Survey and Research,2009,33(3):161-174.
[29]李大中，于士祥，王泽．辽宁岫岩地区岫玉成矿规律探讨[J]．地质找矿论丛，2013,28(2):249-255.Li D Z,Yu S X,Wang Z. Discussion on the jadeforming regularity of Xiuyan jade in Xiuyan area,Liaoning Province[J]. Contributions to Geology and Mineral Resources Research,2013,28(2):249-255.
[30]刘喜锋，刘琰，李自静，等．新疆皮山镁质矽卡岩矿床(含糖玉)成因及锆石SHRIMP U-Pb定年[J]．岩石矿物学杂志，2017,36(2):259-273.Liu X F,Liu Y,Li Z J,et al. The genesis of Mg-skarn deposit(bearing brown nephrite)and its Ar-Ar dating of phlogopite and SHRIMP U-Pb dating of zircon,Pishan,Xinjiang[J]. Acta Petrologica et Mineralogica,2017,36(2):259-273.
[31]张勇，魏华，陆太进，等．新疆奥米夏和田玉矿床成因及锆石LA-ICP-MS定年研究[J]．岩矿测试，2018,37(6):695-704.Zhang Y,Wei H,Lu T J,et al. The genesis and LA-ICP-MS zircon ages of the Omixia nephrite deposit,Xinjiang,China[J]. Rock and Mineral Analysis,2018,37(6):695-704.
[32]贾玉衡，刘喜锋，刘琰，等．新疆且末碧玉矿的成因研究[J]．岩石矿物学杂志，2018,37(5):824-838.Jia Y H,Liu X F,Liu Y,et al. Petrogenesis of the serpentinite-related nephrite deposit in Qiemo County,Xinjiang[J]. Acta Petrologica et Mineralogica,2018,37(5):824-838.