新疆且末碧玉矿的成因研究
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摘要
以往勘察和研究显示,在新疆和田及其附近地区主要出现与大理岩相关的软玉(和田玉)矿床,而与蛇纹岩有关的软玉(碧玉)矿床尚未有明确报道。笔者通过两年多的野外勘察和室内实验分析,新近在且末县阿尔金断裂附近发现一定规模可开采的碧玉矿床,对其中碧玉样品进行了主量元素、微量元素、电子探针、氧同位素和成矿年龄等方面的研究。岩相学研究显示其主要组成矿物是阳起石和透闪石,全岩的Mg/(Mg+Fe~(2+))=0.83~0.89,Cr_2O_3=0.08%~1.65%,Ni O=0.14%~0.22%,δ~(18)O=15.2‰~15.4‰,经与世界上已发现的碧玉矿床进行对比并结合野外观察,确定该矿床是一种与蛇纹岩有关的碧玉矿床。蚀变闪长岩(δ~(18)O=14.3‰~14.7‰)、大理岩围岩(δ~(18)O=15.2‰~15.9‰)和透闪石(δ~(18)O=15.3‰)具有相似的氧同位素组成,表明它们很可能经历了同样的流体蚀变作用。根据蚀变闪长岩(Cr=107×10~(-6)~155×10~(-6),Ni=53.5×10~(-6)~85.8×10~(-6))和大理岩(Cr=2 036×10~(-6)~2 415×10~(-6),Ni=1 403×10~(-6)~1 933×10~(-6))中的Cr、Ni元素含量判断,碧玉中大量的Cr(867×10~(-6)~2 418×10~(-6))和Ni(960×10~(-6)~1 662×10~(-6))很可能来自于蛇纹岩中的流体。对碧玉的主要围岩蚀变闪长岩进行的锆石SHRIMP U-Pb年龄测试结果分别为267±14 Ma(n=5)和272±14 Ma(n=6),与碧玉密切共生的黑云母的Ar-Ar坪年龄为260.6±1.5 Ma。鉴于蚀变闪长岩的形成时代与黑云母年龄数值在误差范围内一致,花岗岩、大理岩和碧玉的氧同位素值接近,同时碧玉的Cr、Ni元素含量较高,因此推断碧玉的物质来源很可能是蚀变闪长岩和大理岩,而成矿流体是由蚀变闪长岩中的岩浆水、蛇纹岩中活化的流体和大气降水组成。
According to the modes of occurrence, nephrite can be divided into dolomite-related nephrite and serpentinite-related nephrite. In previous studies and exploration, serpentinite-related nephrite was hardly found in Hetian dolomite-related nephrite belt in Western Kunlun Mountains. During 2014 ~ 2015, lots of geological examination and collection of information concerning the location of serpentinite-related nephrite were carried out, and then some information about the occurrence of serpentinite-related nephrite orebody near the Altun fault zone was found in Qiemo County. Based on EMPA( electron microprobe analysis), XRF( X-ray fluorescence), ICP-MS( inductively coupled plasma mass spectrometry) and oxygen isotopic analysis, δ~(18) O( 15. 2‰ ~ 15. 4‰), Mg/( Mg +Fe~(2 +)) = 0. 83 ~ 0. 89, Cr_2 O_3= 0. 08% ~ 1. 65%, Ni O = 0. 14% ~ 0. 22% and other geochemical data were acquired, which suggest a serpentinite-related nephrite origin. Wall rock of diorite also indicates that they formed at267 ± 14 Ma and 272 ± 14 Ma, as shown by the SHRIMP U-Pb dating on zircons, which suggests the upper limit of the formation time of the serpentinite-related nephrite. Inverse isochronal age of Ar-Ar dating on biotite associated with serpentinite-related nephrite is 260. 6 ± 1. 5 Ma. Both ages imply that they have relationship in genesis. Possibly due to the similar hydrothermal alteration of diorite, dolomite marble and tremolite, they have the close oxygen isotopic values( δ~(18 )O = 14. 3‰ ~ 14. 7‰, δ~(18 )O = 15. 2‰ ~ 15. 9‰ and δ~(18 )O = 15. 3‰). According to the chemical composition from bulk analysis of diorite( Cr = 107 × 10~(-6)~ 155 × 10~(-6), Ni = 53. 5 × 10~(-6)~ 85. 8 × 10~(-6)),marble( Cr = 2 036 × 10~(-6)~ 2 415 × 10~(-6), Ni = 1 403 × 10~(-6)~ 1 933 × 10~(-6)) and nephrite( Cr = 867 × 10~(-6)~2 418 × 10~(-6), Ni = 960 × 10~(-6)~ 1 662 × 10~(-6)), together with the occurrence of chromite in nephrite, it is concluded that granodiorite and marble provided the ore materials for the formation of nephrite, and hydrothermal fluids were probably derived from both magmatic water and meteoric water in serpentine rock.
According to the modes of occurrence, nephrite can be divided into dolomite-related nephrite and serpentinite-related nephrite. In previous studies and exploration, serpentinite-related nephrite was hardly found in Hetian dolomite-related nephrite belt in Western Kunlun Mountains. During 2014 ~ 2015, lots of geological examination and collection of information concerning the location of serpentinite-related nephrite were carried out, and then some information about the occurrence of serpentinite-related nephrite orebody near the Altun fault zone was found in Qiemo County. Based on EMPA( electron microprobe analysis), XRF( X-ray fluorescence), ICP-MS( inductively coupled plasma mass spectrometry) and oxygen isotopic analysis, δ~(18) O( 15. 2‰ ~ 15. 4‰), Mg/( Mg +Fe~(2 +)) = 0. 83 ~ 0. 89, Cr_2 O_3= 0. 08% ~ 1. 65%, Ni O = 0. 14% ~ 0. 22% and other geochemical data were acquired, which suggest a serpentinite-related nephrite origin. Wall rock of diorite also indicates that they formed at267 ± 14 Ma and 272 ± 14 Ma, as shown by the SHRIMP U-Pb dating on zircons, which suggests the upper limit of the formation time of the serpentinite-related nephrite. Inverse isochronal age of Ar-Ar dating on biotite associated with serpentinite-related nephrite is 260. 6 ± 1. 5 Ma. Both ages imply that they have relationship in genesis. Possibly due to the similar hydrothermal alteration of diorite, dolomite marble and tremolite, they have the close oxygen isotopic values( δ~(18 )O = 14. 3‰ ~ 14. 7‰, δ~(18 )O = 15. 2‰ ~ 15. 9‰ and δ~(18 )O = 15. 3‰). According to the chemical composition from bulk analysis of diorite( Cr = 107 × 10~(-6)~ 155 × 10~(-6), Ni = 53. 5 × 10~(-6)~ 85. 8 × 10~(-6)),marble( Cr = 2 036 × 10~(-6)~ 2 415 × 10~(-6), Ni = 1 403 × 10~(-6)~ 1 933 × 10~(-6)) and nephrite( Cr = 867 × 10~(-6)~2 418 × 10~(-6), Ni = 960 × 10~(-6)~ 1 662 × 10~(-6)), together with the occurrence of chromite in nephrite, it is concluded that granodiorite and marble provided the ore materials for the formation of nephrite, and hydrothermal fluids were probably derived from both magmatic water and meteoric water in serpentine rock.
引文
Adams C J,Beck R J and Camp bell H J.2007.Characterisation and origin of New Zealand nephrite jade using its strontium isotopic signature[J].Lithos,97:307~322.
Adamo I and Bocchio R.2013.Nephrite jade from Val Malenco,Italy:Review and update[J].Gems and Gemology,49:98~106.
Aitchison J C,Ireland T R and Blake Jr.1992.530 Ma zircon age for ophiolite from the New England orogen:Oldest rocks known from eastern Australia[J].Geology,20:125~128.
Black L P,Kamob S L,Allenc C M,et al.2003.TEMORA 1:a new zircon standard for Phanerozoic U-Pb geochronology[J].Chemical Geology,200:155~170.
Clayton R N and Mayeda T K.1963.The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis[J].Geochimica et Cosmochimica Acta,27:43~52.
Compston W,Williams I S,Kirschvink,J L,et al.,1992.Zircon U-Pb ages for the Early Cambrian time-scale[J],Journal of the Geological Society,149:171~184.
Dietrich V and de Quervain F.1968.Die Nephrit-Talklagersttte Scortaseo(Puschlav,Kanton Graubünden).bersicht der Weiteren Nephritfunde der Schweizer Alpen Insbesondere der Vorkommen im Oberhalbstein(Graubünden)[J].Beitrge zur Geologie der Schweiz,Geotechnische Serie,46.
Faure G.1998.Isotope geochronology and its applications to geology[J].Earth Science Frontiers,5(1~2):17~39.
Geological and Mineral Resources Bureau of Xinjiang Uygur Autonomous Region.1982.Regional Geological Records of Xinjiang Uygur Autonomous Region:Regional Geology[M].Geology Publishing House,32,556~557(in Chinese).
Gil G.2013.Petrographic and microprobe study of nephrites from Lower Silesia(SW Po land)[J].Geological Quarterly,57(3):395~404.
Gil G,Barnes J D,Boschi C,et al.2015a.Nephrite from Zloty Stok(Sudetes,SW Poland):Petrological,geochemical and isotopic evidence for a dolomite-related origin[J].The Canadian Mineralogist,53:533~556.
Gil G,Baenes J D,Boschi C,et al.2015b.Origin of serpentinite-relate nephrite from Jordanow and adjacent ares(SW Poland)and its comparison with selected nephrite occurences[J].Geological Quarterly,59(3):457~472.
Grapes R H and Yun S T.2010.Geochemistry of a New Zeland nephrite weathering rind[J].New Zealand Journal of Geology and Geophysics,53:413~426.
Gunia P.2000.Nephrite from South-Western Poland as potential raw material of the European Neolithic artefacts[J].Krystalinikum,26:167~171.
Harlow G E and Sorensen S S.2001.Jade:Occurrence and metasomatic origin[A].31st International Geologic Congress 2000[C].The Australian Gemmologist,21:7~10.
Harlow G E and Sorensen S S.2005.Jade(nephrite and jadeitite)and serpentinite:Metasomatic connections[J].International Geology Review,47:113~146.
He H Y,Wang X L,Jin F,et al.2006.The40Ar/39Ar dating of the early Jehol Biota from Fengning,Hebei Province,northern China[J].Geochem.Geophys Geosyst.,7,doi:10.1029/2005GC001083.
Kostov R I,Protochristov C,Stoyanov C,et al.2012.Micro-PIXE geochemical fingerprinting of nephrite Neolithic artifacts from South west Bulgaria[J].Geoarchaeology:An International Journal,27:457~469.
Leake B E,Woolley A R and Arpes C E S.1997.Nomenclature of amphiboles.report of the.Subcommittee on amphiboles of the International Mineralogical Association,Commission on New Minerals and Mineral Names[J].American Mineralogist,82:1 019~1 037.
Ling X,Schmdicke E,Wu R,et al.2013.Composition and distinction of white nephrite from Asian deposits[J].Neues Jahrbuch für Mineralogie-Abhandlungen(Journal of Mineralogy and Geochemistry),190/1:49~65.
Liu Y,Deng J,Shi G H,et al.2010.Chemical zone of nephrite in Almas,Xinjiang,China[J].Resour.Geol.,60:249~259.
Liu Y,Deng J,Shi G H,et al.2011a.Geochemistry and petrology of nephrite from Alamas,Xinjiang,NW China[J].Journal of Asian Earth Sciences,42:440~451.
Liu Y,Deng J,Shi G H,et al.2011b.Geochemistry and petrogenesis of placer nephrite from Hetian,Xinjiang[J].Ore Geology Reviews,41:122~132.
Liu Y,Zhang R Q,Abuduwayiti M,et al.2016.SHRIMP U-Pb 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,72:699~727.
Liu Y,Zhang R Q,Zhang Z Y,et al.2015b.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,212~215:128~144.
Ludwig K R.2001.Squid 1.02:a user's manual[J].Berkeley Geochronology Center Special,2:1~21.
Ludwig K R.2003.User's Manual for Isoplot 3.00:A Geochronological Toolkit for Microsoft Excel[M].Berkeley Geochronology Center Special.
Middleton A.2006.JADE-Geology and Mineralogy[A].O'Donoghue M.Gems[C].Oxford:Elsevier Ltd.,332~354.
Nasdala L,Hofmeister W,Norberg N,et al.2008.Zircon M257-A homogeneous natural reference material for the ion microprobe U-Pb analysis of zircon[J].Geostand Geoanal Res.,32:247~265.
Péterdi B,Szakmány G,Judik K et al.2014.Petrographic and geochemical in vestigaion of a stone adze made of nephrite from the Balaton7sz9d-Temet7i d0l7 site(Hungary),with a review of the nephrite occur rences in Europe(especially in Switzerland and in the Bohemian Massif)[J].Geological Quarterly,58(1):181~192.
Pirajno F,Mao J W and Zhang Z C.2008.The association of maficeultramafic intrusions and A-type magmatism in the Tianshan and Altay orogens,NW China:Implications for geodynamic evolution and potential for the discovery of new ore deposits[J].Asian Earth Sci.,32:165~183.
Siqin B,Qian R,Zhuo S,et al.2012.Glow discharge mass spectrometry studies on nephrite minerals formed by different metal logenic mechanisms and geological environments[J].International Journal of Mass Spectrometry,309:206~211.
Stern R A.1998.High-resolution SIMS determination of radiogenic tracer-isotope ratios in minerals[A].Cabri L J and Vaughan D J.Modern Approaches to Ore and Environmental Mineralogy[C].27:241~268.
Yui T F and Kwon S T.2002.Origin of a dolomite-related jade deposit at Chuncheon,Korea[J].Economic Geology,97:593~601.
Yui T F,Yeh H W,Lee C W,et al.1988.Stable isotope studies of nephrite deposits from Fengtian,Taiwan[J].Geochimica et Cosmochimica Acta,52:593~602.
Zhang Fan,Qiu Huaning,He Huanyu,et al.2009.Brief introduction to Ar Ar CALC-Software for data reduction40Ar/39Ar geochronology[J].Geochimica,38(1):53~56(in Chinese with English abstract).
新疆维吾尔自治区地质矿产局.1982.新疆维吾尔自治区区域地质志:区域地质[M].北京:地质出版社,32,556~557.
张凡,邱华宁,贺怀宇,等.2009.40Ar/39Ar年代学数据处理软件Ar Ar CALC简介[J].地球化学,38(1):53~56.
Adamo I and Bocchio R.2013.Nephrite jade from Val Malenco,Italy:Review and update[J].Gems and Gemology,49:98~106.
Aitchison J C,Ireland T R and Blake Jr.1992.530 Ma zircon age for ophiolite from the New England orogen:Oldest rocks known from eastern Australia[J].Geology,20:125~128.
Black L P,Kamob S L,Allenc C M,et al.2003.TEMORA 1:a new zircon standard for Phanerozoic U-Pb geochronology[J].Chemical Geology,200:155~170.
Clayton R N and Mayeda T K.1963.The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis[J].Geochimica et Cosmochimica Acta,27:43~52.
Compston W,Williams I S,Kirschvink,J L,et al.,1992.Zircon U-Pb ages for the Early Cambrian time-scale[J],Journal of the Geological Society,149:171~184.
Dietrich V and de Quervain F.1968.Die Nephrit-Talklagersttte Scortaseo(Puschlav,Kanton Graubünden).bersicht der Weiteren Nephritfunde der Schweizer Alpen Insbesondere der Vorkommen im Oberhalbstein(Graubünden)[J].Beitrge zur Geologie der Schweiz,Geotechnische Serie,46.
Faure G.1998.Isotope geochronology and its applications to geology[J].Earth Science Frontiers,5(1~2):17~39.
Geological and Mineral Resources Bureau of Xinjiang Uygur Autonomous Region.1982.Regional Geological Records of Xinjiang Uygur Autonomous Region:Regional Geology[M].Geology Publishing House,32,556~557(in Chinese).
Gil G.2013.Petrographic and microprobe study of nephrites from Lower Silesia(SW Po land)[J].Geological Quarterly,57(3):395~404.
Gil G,Barnes J D,Boschi C,et al.2015a.Nephrite from Zloty Stok(Sudetes,SW Poland):Petrological,geochemical and isotopic evidence for a dolomite-related origin[J].The Canadian Mineralogist,53:533~556.
Gil G,Baenes J D,Boschi C,et al.2015b.Origin of serpentinite-relate nephrite from Jordanow and adjacent ares(SW Poland)and its comparison with selected nephrite occurences[J].Geological Quarterly,59(3):457~472.
Grapes R H and Yun S T.2010.Geochemistry of a New Zeland nephrite weathering rind[J].New Zealand Journal of Geology and Geophysics,53:413~426.
Gunia P.2000.Nephrite from South-Western Poland as potential raw material of the European Neolithic artefacts[J].Krystalinikum,26:167~171.
Harlow G E and Sorensen S S.2001.Jade:Occurrence and metasomatic origin[A].31st International Geologic Congress 2000[C].The Australian Gemmologist,21:7~10.
Harlow G E and Sorensen S S.2005.Jade(nephrite and jadeitite)and serpentinite:Metasomatic connections[J].International Geology Review,47:113~146.
He H Y,Wang X L,Jin F,et al.2006.The40Ar/39Ar dating of the early Jehol Biota from Fengning,Hebei Province,northern China[J].Geochem.Geophys Geosyst.,7,doi:10.1029/2005GC001083.
Kostov R I,Protochristov C,Stoyanov C,et al.2012.Micro-PIXE geochemical fingerprinting of nephrite Neolithic artifacts from South west Bulgaria[J].Geoarchaeology:An International Journal,27:457~469.
Leake B E,Woolley A R and Arpes C E S.1997.Nomenclature of amphiboles.report of the.Subcommittee on amphiboles of the International Mineralogical Association,Commission on New Minerals and Mineral Names[J].American Mineralogist,82:1 019~1 037.
Ling X,Schmdicke E,Wu R,et al.2013.Composition and distinction of white nephrite from Asian deposits[J].Neues Jahrbuch für Mineralogie-Abhandlungen(Journal of Mineralogy and Geochemistry),190/1:49~65.
Liu Y,Deng J,Shi G H,et al.2010.Chemical zone of nephrite in Almas,Xinjiang,China[J].Resour.Geol.,60:249~259.
Liu Y,Deng J,Shi G H,et al.2011a.Geochemistry and petrology of nephrite from Alamas,Xinjiang,NW China[J].Journal of Asian Earth Sciences,42:440~451.
Liu Y,Deng J,Shi G H,et al.2011b.Geochemistry and petrogenesis of placer nephrite from Hetian,Xinjiang[J].Ore Geology Reviews,41:122~132.
Liu Y,Zhang R Q,Abuduwayiti M,et al.2016.SHRIMP U-Pb 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,72:699~727.
Liu Y,Zhang R Q,Zhang Z Y,et al.2015b.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,212~215:128~144.
Ludwig K R.2001.Squid 1.02:a user's manual[J].Berkeley Geochronology Center Special,2:1~21.
Ludwig K R.2003.User's Manual for Isoplot 3.00:A Geochronological Toolkit for Microsoft Excel[M].Berkeley Geochronology Center Special.
Middleton A.2006.JADE-Geology and Mineralogy[A].O'Donoghue M.Gems[C].Oxford:Elsevier Ltd.,332~354.
Nasdala L,Hofmeister W,Norberg N,et al.2008.Zircon M257-A homogeneous natural reference material for the ion microprobe U-Pb analysis of zircon[J].Geostand Geoanal Res.,32:247~265.
Péterdi B,Szakmány G,Judik K et al.2014.Petrographic and geochemical in vestigaion of a stone adze made of nephrite from the Balaton7sz9d-Temet7i d0l7 site(Hungary),with a review of the nephrite occur rences in Europe(especially in Switzerland and in the Bohemian Massif)[J].Geological Quarterly,58(1):181~192.
Pirajno F,Mao J W and Zhang Z C.2008.The association of maficeultramafic intrusions and A-type magmatism in the Tianshan and Altay orogens,NW China:Implications for geodynamic evolution and potential for the discovery of new ore deposits[J].Asian Earth Sci.,32:165~183.
Siqin B,Qian R,Zhuo S,et al.2012.Glow discharge mass spectrometry studies on nephrite minerals formed by different metal logenic mechanisms and geological environments[J].International Journal of Mass Spectrometry,309:206~211.
Stern R A.1998.High-resolution SIMS determination of radiogenic tracer-isotope ratios in minerals[A].Cabri L J and Vaughan D J.Modern Approaches to Ore and Environmental Mineralogy[C].27:241~268.
Yui T F and Kwon S T.2002.Origin of a dolomite-related jade deposit at Chuncheon,Korea[J].Economic Geology,97:593~601.
Yui T F,Yeh H W,Lee C W,et al.1988.Stable isotope studies of nephrite deposits from Fengtian,Taiwan[J].Geochimica et Cosmochimica Acta,52:593~602.
Zhang Fan,Qiu Huaning,He Huanyu,et al.2009.Brief introduction to Ar Ar CALC-Software for data reduction40Ar/39Ar geochronology[J].Geochimica,38(1):53~56(in Chinese with English abstract).
新疆维吾尔自治区地质矿产局.1982.新疆维吾尔自治区区域地质志:区域地质[M].北京:地质出版社,32,556~557.
张凡,邱华宁,贺怀宇,等.2009.40Ar/39Ar年代学数据处理软件Ar Ar CALC简介[J].地球化学,38(1):53~56.