新疆西南天山阿万达金矿区赋矿围岩物源及形成时代:碎屑锆石U-Pb年代学制约
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摘要
阿万达金矿位于西南天山造山带内。此次研究在简要总结其矿床地质特征基础上,对与阿万达金矿成矿密切相关的阿克苏群中硅质片岩围岩分别进行了岩石地球化学分析和LA-ICP-MS碎屑锆石U-Pb定年研究,以期对围岩的沉积环境、物源及形成时代进行讨论。岩石地球化学分析结果显示,阿万达金矿赋矿围岩中硅质片岩的原岩可能为一套成熟度较低的泥岩或砂岩,物源主要为石英岩质沉积物,沉积环境可能处于活动大陆弧内的沉积盆地内。U-Pb定年结果显示,其碎屑锆石定年数据主要形成了加权平均年龄值为405 Ma或406 Ma的年龄峰,其谐和年龄最小峰值即405 Ma可以作为其最大沉积年龄。因此笔者认为阿克苏群中硅质片岩的沉积时代并不是前人所定的长城纪,而是不老于早泥盆世。另外,这一地层的物源组成具有多样性,～405 Ma碎屑锆石占主体,可能与哈尔克山北缘火山弧内的早泥盆世岩浆活动有关;～745Ma的碎屑锆石的出现,表明其物源有少部分来自新元古代岩石;极少数～2.50 Ga的碎屑锆石的出现,反映了华北地台对本地层有物源上的贡献。
The Awanda gold deposit is located in the Southwestern Tianshan Orogenic Belt.On the basis of the geological characteristics of the Awanda gold deposit,the authors applied petrological geochemistry and LA-ICP-MS detrital zircon U-Pb dating of the siliceous schist wall rocks from the So-called Aksu Group,which is closely related to the mineralization of Awanda gold deposit,with an aim to understand depositional environment,provenance and age of these rocks.The results of petrochemistrical analysis show that the protoliths of the ore-hosting strata are possibly composed of mudstones and sandstones with low maturity.Most of the provenances are quartzose sediments and the depsotional environment is likely related to depositional basin nearby the active continent margin.LA-ICP-MS detrital zircon U-Pb date indicates that the zircon ages have peaks of weighted age of 405 or 406 Ma.The youngest peak age of these concordant age data is 405 Ma which could be regarded as the maximum sedimentary age.Therefore,it was considered that the sedimentary age of the so-called Aksu group ore-hosting strata is not older than the Early Devonian,rather than the Changcheng period as previously reported.In addition,the provenances of the strata are multiform.Among the analytic data,the～405 Ma detrital zircons occupy the principal part,which could be related to the magmatic activity in the northern rim of the Early Devonian volcanic arc of the Haerke Mountain.The～745 Ma detrital zircons suggest that small part of the material source comes from Neoproterozoic rocks.Several～2.50 Ga detrital zircons reflect that North China block makes few contributions of material sources to the strata.
The Awanda gold deposit is located in the Southwestern Tianshan Orogenic Belt.On the basis of the geological characteristics of the Awanda gold deposit,the authors applied petrological geochemistry and LA-ICP-MS detrital zircon U-Pb dating of the siliceous schist wall rocks from the So-called Aksu Group,which is closely related to the mineralization of Awanda gold deposit,with an aim to understand depositional environment,provenance and age of these rocks.The results of petrochemistrical analysis show that the protoliths of the ore-hosting strata are possibly composed of mudstones and sandstones with low maturity.Most of the provenances are quartzose sediments and the depsotional environment is likely related to depositional basin nearby the active continent margin.LA-ICP-MS detrital zircon U-Pb date indicates that the zircon ages have peaks of weighted age of 405 or 406 Ma.The youngest peak age of these concordant age data is 405 Ma which could be regarded as the maximum sedimentary age.Therefore,it was considered that the sedimentary age of the so-called Aksu group ore-hosting strata is not older than the Early Devonian,rather than the Changcheng period as previously reported.In addition,the provenances of the strata are multiform.Among the analytic data,the～405 Ma detrital zircons occupy the principal part,which could be related to the magmatic activity in the northern rim of the Early Devonian volcanic arc of the Haerke Mountain.The～745 Ma detrital zircons suggest that small part of the material source comes from Neoproterozoic rocks.Several～2.50 Ga detrital zircons reflect that North China block makes few contributions of material sources to the strata.
引文
陈富文,李华芹.2003.新疆萨瓦亚尔顿金锑矿床成矿作用同位素地质年代学[J].地球学报,24(6):563-567.
第五春荣,孙勇,袁洪林,等.2008.河南登封地区嵩山石英岩碎屑锆石U-Pb年代学、Hf同位素组成及其地质意义[J].科学通报,53(16):1923-1934.
董新丰,薛春纪,石福品.2011.新疆西天山大山口金矿地质及成矿流体包裹体地球化学[J].地学前缘,18(5):172-181.
韩宝福,何国琦,吴泰然,等.2004.天山早古生代花岗岩锆石U-Pb定年、岩石地球化学特征及其大地构造意义[J].新疆地质,22(1):4-11.
李建兵.2010.新疆西南天山晚古生代沉积盆地及大地构造演化[D].成都:成都理工大学.
李明.2010.中国东北现代河流碎屑锆石U-Pb年代学和Hf同位素研究及大陆生长与演化[D].武汉:中国地质大学.
吴昌华,孙敏,李惠民,等.2006.乌拉山-集宁孔兹岩锆石激光探针等离子质谱(LA-ICP-MS)年龄:孔兹岩沉积时限的年代学研究[J].岩石学报,22(11):2639-2654.
新疆地矿局第八地质大队.2012.新疆拜城县阿万达金矿预查报告[R].阿克苏:新疆地矿局第八地质大队.
新疆维吾尔族自治区地质调查院.2004.新疆1:25万喀赞其幅(K44C002004)区域地质调查成果报告[R].乌鲁木齐:新疆维吾尔族自治区地质调查院.
杨富全,毛景文,王义天,等.2007.新疆西南天山金矿床主要类型、特征及成矿作用[J].矿床地质,26(4):361-379.
杨富全.2005.西南天山成矿条件及成矿机制[D].北京:中国地质科学院.
杨建国,闫晔轶,徐学义,等.2004.西南天山成矿规律及其与境外对比研究[J].矿床地质,23(1):20-30.
翟明国.2010.华北克拉通的形成演化与成矿作用[J].矿床地质,29(1):24-36.
翟明国,彭澎.2007.华北克拉通古元古代构造事件[J].岩石学报,23(11):2665-2682.
张振法.1998.论塔里木地台与华北地台的关系[J].物探与化探,22(5):384-393.
朱志新,李锦轶,董莲慧,等.2009.新疆南天山构造格架及构造演化[J].地质通报,28(12):1863-1870.
朱志新.2007.新疆南天山地质组成及构造演化[D].北京:中国地质科学院.
Andersen T.2002.Correction of common lead in U-Pb analyses that do not report204Pb[J].Chemical Geology,192(1/2):59-79.
Bhat M I and Ghosh S K.2001.Geochemistry of the 2.51 Ga old Rampur group pelites,western Himalayas:implications for their provenance and weathering[J].Precambrian Research,108:1-16.
Bhatia M R.1983.Plate tectonics and geochemical composition of sandstones[J].The Journal of Geology,91:611-627.
Bhatia M R and Crook K A W.1986.Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins[J]Contrib Mineral Petrol,92:181-193.
Blank L P,Kamo S L,Williams I S,et al.2003.The application of SHEIMPto Phanerozoic geochronology:A critical appraisal of four zircon standards[J].Chemical Geology,200:171-188.
Chen H Y,Chen Y J and Baker M.2012.Isotopic geochemistry of the Sawayaerdun orogenic-type gold deposit,Tianshan,northwest China Implications for ore genesis and mineral exploration[J].Chemical Geology,310:1-11.
Cullers R L and Podkovyrov V N.2000.Geochemistry of the Mesoproterozoic Lakhanda shales in southeastern Yakutia,Russia:implications for mineralogical and provenance control,and recycling[J].Precambrian Reserch,104:77-93.
Ding Qingfeng,WU Changzhi,Santosh M,et al.2014.H,O,S and Pb isotope geochemistry of the Awanda gold deposit in southern Tianshan,Central Asian Orogenic Belt:Implications for fluid regime and metallogeny[J]Ore Geology Reviews,62:40-53.
Fedo C M,Eriksson K A and Krogstad E J.1996.Geochemistry of shales from the Archean(~3.0 Ga)Buhwa Greenstone Belt,Zimbabwe:implications for provenance and source-area weathering[J].Geochimica et Cosmochimica Acta,60(10):1751-1763.
Gao Shan,Ling Wenli,Qiu Yumin,et al.1999.Contrasting geochemical and Sm-Nd isotopic composition of Archean metasediments from the Kongling high-grade terrain of the Yangtze craton:Evidence for cratonic evolution and redistribution of REE during crustal anatexis[J]Geochimica et Cosmochimica Acta,63(13):2071-2088.
Hoskin P W O and Sehaltegger U.2003.The composition of zircon and igneous and metamorphic petrogenesis[J].Reviews in Mineralogy and Geoehemistry,53(1):27-62.
Joo Y J,Lee Y I and Bai Zhiqiang.2005.Provenance of the Qingshuijian Formation(Late Carboniferous)NE China:implications for tectonic processes in the northern margin of the North China block[J].Sediment Geology,177:97-114.
Mclennan S M.1989.Rare earth elements in sedimentary rocks:influence of provenance and sedimentary processe[J].Review in Mineralogy and Geochemistry,21(1):169-200
Nesbitt H W and Young G M.1982.Early Proterozoic climates and plate motions inferred from mayor element chemistry of lutites[J].Nature,299:715-717.
Niggli P.1954.Rocks and Mineral Deposits[M].San Francisco:W HFreeman and Company.
Roser B P and Korsch R J.1986.Determination of tectonic setting of sandstone-mudstone suites using Si O2content and K2O/Na2O ratio[J].Journal of Geology,94(5):635-650.
Roser B P and Korsch R J.1999.Geochemical characterization,evolution and source of a Mesozoic Accretionary wedge:the Torlesse terrane,New Zealand[J].Geological Magazine,136(5):493-512.
Roser B P and Korsch R J.1988.Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data[J].Chemical geology,67(1):119-139.
Simonen A J P.1953.Stratigraphy and Sedimentation of the Svecofennidic,Early Archean Supracrustal Rocks in Southwestern Finland[M].Goverment press:160.
Wilde A R,Layer P,Mernagh T,et al.2001.The giant muruntau gold deposit:Geologic,geochronologic and fluid inclusion constraints on ore genesis[J].Econimic Geology,96:633-644.
Yang Shuiyan,Jiang Shaoyong,Jiang Yaohui,et al.2011.Geochemical,zircon U-Pb dating and Sr-Nd-Hf isotopic constraints on the age and petrogenesis of an Early Cretaceous volcanic-intrusive complex at Xiangshan,Southeast China[J].Mineralogy and Petrology,101(1-2):21-48.
Zhao Gunchun,Sun Min,Wilde S A,et al.2005.Late Archean to Paleoproterozoic evolution of the North China Craton:Key issues revisited[J].Precambrain Research,136(2):177-202.
Zhu Wenbin,Zheng Bihai,Shu Liangshu,et al.2011.Neoproterozoic tectonic evolution of the Precambrian Aksu Blueschist Terrane,Northwestern Tarim,China:Insights from LA-ICP-MS zircon U-Pb ages and geochemical data[J].Precambrian Research,185(3-4):215-230.
第五春荣,孙勇,袁洪林,等.2008.河南登封地区嵩山石英岩碎屑锆石U-Pb年代学、Hf同位素组成及其地质意义[J].科学通报,53(16):1923-1934.
董新丰,薛春纪,石福品.2011.新疆西天山大山口金矿地质及成矿流体包裹体地球化学[J].地学前缘,18(5):172-181.
韩宝福,何国琦,吴泰然,等.2004.天山早古生代花岗岩锆石U-Pb定年、岩石地球化学特征及其大地构造意义[J].新疆地质,22(1):4-11.
李建兵.2010.新疆西南天山晚古生代沉积盆地及大地构造演化[D].成都:成都理工大学.
李明.2010.中国东北现代河流碎屑锆石U-Pb年代学和Hf同位素研究及大陆生长与演化[D].武汉:中国地质大学.
吴昌华,孙敏,李惠民,等.2006.乌拉山-集宁孔兹岩锆石激光探针等离子质谱(LA-ICP-MS)年龄:孔兹岩沉积时限的年代学研究[J].岩石学报,22(11):2639-2654.
新疆地矿局第八地质大队.2012.新疆拜城县阿万达金矿预查报告[R].阿克苏:新疆地矿局第八地质大队.
新疆维吾尔族自治区地质调查院.2004.新疆1:25万喀赞其幅(K44C002004)区域地质调查成果报告[R].乌鲁木齐:新疆维吾尔族自治区地质调查院.
杨富全,毛景文,王义天,等.2007.新疆西南天山金矿床主要类型、特征及成矿作用[J].矿床地质,26(4):361-379.
杨富全.2005.西南天山成矿条件及成矿机制[D].北京:中国地质科学院.
杨建国,闫晔轶,徐学义,等.2004.西南天山成矿规律及其与境外对比研究[J].矿床地质,23(1):20-30.
翟明国.2010.华北克拉通的形成演化与成矿作用[J].矿床地质,29(1):24-36.
翟明国,彭澎.2007.华北克拉通古元古代构造事件[J].岩石学报,23(11):2665-2682.
张振法.1998.论塔里木地台与华北地台的关系[J].物探与化探,22(5):384-393.
朱志新,李锦轶,董莲慧,等.2009.新疆南天山构造格架及构造演化[J].地质通报,28(12):1863-1870.
朱志新.2007.新疆南天山地质组成及构造演化[D].北京:中国地质科学院.
Andersen T.2002.Correction of common lead in U-Pb analyses that do not report204Pb[J].Chemical Geology,192(1/2):59-79.
Bhat M I and Ghosh S K.2001.Geochemistry of the 2.51 Ga old Rampur group pelites,western Himalayas:implications for their provenance and weathering[J].Precambrian Research,108:1-16.
Bhatia M R.1983.Plate tectonics and geochemical composition of sandstones[J].The Journal of Geology,91:611-627.
Bhatia M R and Crook K A W.1986.Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins[J]Contrib Mineral Petrol,92:181-193.
Blank L P,Kamo S L,Williams I S,et al.2003.The application of SHEIMPto Phanerozoic geochronology:A critical appraisal of four zircon standards[J].Chemical Geology,200:171-188.
Chen H Y,Chen Y J and Baker M.2012.Isotopic geochemistry of the Sawayaerdun orogenic-type gold deposit,Tianshan,northwest China Implications for ore genesis and mineral exploration[J].Chemical Geology,310:1-11.
Cullers R L and Podkovyrov V N.2000.Geochemistry of the Mesoproterozoic Lakhanda shales in southeastern Yakutia,Russia:implications for mineralogical and provenance control,and recycling[J].Precambrian Reserch,104:77-93.
Ding Qingfeng,WU Changzhi,Santosh M,et al.2014.H,O,S and Pb isotope geochemistry of the Awanda gold deposit in southern Tianshan,Central Asian Orogenic Belt:Implications for fluid regime and metallogeny[J]Ore Geology Reviews,62:40-53.
Fedo C M,Eriksson K A and Krogstad E J.1996.Geochemistry of shales from the Archean(~3.0 Ga)Buhwa Greenstone Belt,Zimbabwe:implications for provenance and source-area weathering[J].Geochimica et Cosmochimica Acta,60(10):1751-1763.
Gao Shan,Ling Wenli,Qiu Yumin,et al.1999.Contrasting geochemical and Sm-Nd isotopic composition of Archean metasediments from the Kongling high-grade terrain of the Yangtze craton:Evidence for cratonic evolution and redistribution of REE during crustal anatexis[J]Geochimica et Cosmochimica Acta,63(13):2071-2088.
Hoskin P W O and Sehaltegger U.2003.The composition of zircon and igneous and metamorphic petrogenesis[J].Reviews in Mineralogy and Geoehemistry,53(1):27-62.
Joo Y J,Lee Y I and Bai Zhiqiang.2005.Provenance of the Qingshuijian Formation(Late Carboniferous)NE China:implications for tectonic processes in the northern margin of the North China block[J].Sediment Geology,177:97-114.
Mclennan S M.1989.Rare earth elements in sedimentary rocks:influence of provenance and sedimentary processe[J].Review in Mineralogy and Geochemistry,21(1):169-200
Nesbitt H W and Young G M.1982.Early Proterozoic climates and plate motions inferred from mayor element chemistry of lutites[J].Nature,299:715-717.
Niggli P.1954.Rocks and Mineral Deposits[M].San Francisco:W HFreeman and Company.
Roser B P and Korsch R J.1986.Determination of tectonic setting of sandstone-mudstone suites using Si O2content and K2O/Na2O ratio[J].Journal of Geology,94(5):635-650.
Roser B P and Korsch R J.1999.Geochemical characterization,evolution and source of a Mesozoic Accretionary wedge:the Torlesse terrane,New Zealand[J].Geological Magazine,136(5):493-512.
Roser B P and Korsch R J.1988.Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data[J].Chemical geology,67(1):119-139.
Simonen A J P.1953.Stratigraphy and Sedimentation of the Svecofennidic,Early Archean Supracrustal Rocks in Southwestern Finland[M].Goverment press:160.
Wilde A R,Layer P,Mernagh T,et al.2001.The giant muruntau gold deposit:Geologic,geochronologic and fluid inclusion constraints on ore genesis[J].Econimic Geology,96:633-644.
Yang Shuiyan,Jiang Shaoyong,Jiang Yaohui,et al.2011.Geochemical,zircon U-Pb dating and Sr-Nd-Hf isotopic constraints on the age and petrogenesis of an Early Cretaceous volcanic-intrusive complex at Xiangshan,Southeast China[J].Mineralogy and Petrology,101(1-2):21-48.
Zhao Gunchun,Sun Min,Wilde S A,et al.2005.Late Archean to Paleoproterozoic evolution of the North China Craton:Key issues revisited[J].Precambrain Research,136(2):177-202.
Zhu Wenbin,Zheng Bihai,Shu Liangshu,et al.2011.Neoproterozoic tectonic evolution of the Precambrian Aksu Blueschist Terrane,Northwestern Tarim,China:Insights from LA-ICP-MS zircon U-Pb ages and geochemical data[J].Precambrian Research,185(3-4):215-230.