东昆仑马尼特地区晚三叠世侵入岩地球化学特征及地质意义
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摘要
马尼特地区位于东昆仑阿尼玛卿成矿带,为确定该区石英闪长岩的形成时代、源区性质和构造背景,笔者对其进行了LA-ICP-MS锆石U-Pb年代学和同位素和地球化学研究。结果显示岩体侵位时间为(206.8±1.7)Ma(MSWK=0.50),属于晚三叠世。岩石SiO_2含量为57.17%～68.55%,Na_2O、K_2O含量分别为3.31%～5.39%和1.52%～3.37%,全碱ALK=5.19%～7.24%,铝饱和指数A/CNK=0.93～1.25,属准铝质-弱过铝质系列岩石。稀土元素分布模式为轻稀土富集,具弱负Eu异常。岩石具有富集大离子亲石元素(Rb、Ba、K)和不相容元素(U、Th),不同程度亏损Nb、Ta、Ti、P等元素的特征。以上特征表明,岩石为钙碱性-高钾钙碱性的I型花岗岩,结合岩石成岩年龄、地球化学特征以及区域构造演化,岩石具有后碰撞岩浆活动的特征,推测其属于东昆仑地块与巴颜喀拉地块碰撞后地壳部分熔融的产物。
The Manite area is located in the Animaqing metallogenic belt of East Kunlun.In order to determine the formation time,magma source and tectonic setting of the quartz diorite in this area,the zircon LA-ICP-MS U-Pb dating,isotopic composition and geochemistry have been studied in this paper.The results show that the pluton emplacement time is(206.8±1.7)Ma(MSWK=0.50),belonging to the Late Triassic.The quartz diorite have SiO_2 of 57.17% ～68.55%,Na_2O of 3.31%～5.39%,K_2O of 1.52%～3.37%,ALK of 5.19%～7.24% and A/CNK of 0.93～1.25,they are Aluminiums and belong to calc-alkaline rock series.The REE distribution modes show the LREE accumulation and weak negative Eu anomalies.The quartz diorite is characterized by the enrichment of LILEs(Rb,Ba and K)and incompatible elements(U and Th),as well as the depletion of HFSEs(Nb,Ta,Ti and P).Above features show that this rock belongs to high-K calc-alkaline I-type granite.Combined with the geochronological data,geochemical characteristics and the regional tectonic evolution,it's included that this rock has the characteristics of post-collisional magmatism,and the quartz diorite was the product of crustal partial melting after the collision of the East Kunlun block and Bayan Har block.
The Manite area is located in the Animaqing metallogenic belt of East Kunlun.In order to determine the formation time,magma source and tectonic setting of the quartz diorite in this area,the zircon LA-ICP-MS U-Pb dating,isotopic composition and geochemistry have been studied in this paper.The results show that the pluton emplacement time is(206.8±1.7)Ma(MSWK=0.50),belonging to the Late Triassic.The quartz diorite have SiO_2 of 57.17% ～68.55%,Na_2O of 3.31%～5.39%,K_2O of 1.52%～3.37%,ALK of 5.19%～7.24% and A/CNK of 0.93～1.25,they are Aluminiums and belong to calc-alkaline rock series.The REE distribution modes show the LREE accumulation and weak negative Eu anomalies.The quartz diorite is characterized by the enrichment of LILEs(Rb,Ba and K)and incompatible elements(U and Th),as well as the depletion of HFSEs(Nb,Ta,Ti and P).Above features show that this rock belongs to high-K calc-alkaline I-type granite.Combined with the geochronological data,geochemical characteristics and the regional tectonic evolution,it's included that this rock has the characteristics of post-collisional magmatism,and the quartz diorite was the product of crustal partial melting after the collision of the East Kunlun block and Bayan Har block.
引文
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刘战庆,裴先治,李瑞保,等.东昆仑南缘布青山构造混杂岩带的地质特征及大地构造意义[J].地质通报,2011a,30(8):1182-1195.LIU Zhanqing,PEI Xianzhi,LI Ruibao,et al.Geological Characteristics of the Buqingshan Tectonic Melange Belt in the Southern Margin of East Kunlun and its Tectonic Implications[J].Geological Bulletin of China,2011a,30(8):1182-1195.
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莫宣学,罗照华,邓晋福,等.东昆仑造山带花岗岩及地壳生长[J].高校地质学报,2007,13(3):403-414.MO Xuanxue,LUO Zhaohua,DENG Jinfu,et al.Granitoids and Crustal Growth in the East-Kunlun Orogenic Belt[J].Geological Journal of China Universities 2007,13(3):403-414.
裴先治.勉略-阿尼玛卿构造带的形成演化与动力学特征[A].西安:西北大学博士学位论文[D],2001:1-155.PEI Xianzhi.Geological Evolution and Dynamics of the Mianlue-A'nyemaqen Tectonic Zone,Central China[A].Xi'an:Northwest University[D],2001:1-155.
祁生胜.青海省东昆仑造山带火成岩岩石构造组合与构造演化[A].北京:中国地质大学博士学位论文[D],2015:1-334.QI Shengsheng.Petrotectonic assemblages and tectonic evolution of the East Kunlun orogenic belt in Qinghai Province[A].China University of Geosciences(Beijing)[D].2015:1-334.
魏小林,曾小平,甘承萍,等.东昆仑查干尕诺地区中三叠世中酸性侵入岩地球化学特征及地质意义[J].西北地质,2016,49(2):1-10.WEI Xiaolin,ZENG Xiaoping,GAN Chengping,et al.Geochemistry and Geological Significance of IntermediateAcid Intrusive Rock in the Chaganganuo,Eastern Kunlun[J].Northwestern Geology,2016,49(2):1-10.
吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589-1604.WU Yuanbao,ZHENG Yongfei.Genetic Mineralogy of Zircon and its Restriction on U-Pb Age Interpretation[J].Chinese Science Bulletin,2004,49(16):1589-1604.
许志琴,姜枚,杨经绥,等,青藏高原的地幔结构:地幔羽、地幔剪切带及岩石圈俯冲板片的拆沉[J].地学前缘,2004,11(4):329-343.XU Zhiqin,JIANG Mei,YANG Jingsui,et al.Mantle structure of Qinghai-Tibet Plateau:Mantle plume,mantle shear zone and delamination of lithospheric slab[J].Earth Science Frontiers,2004,11(4):329-343.
殷鸿福,张克信.东昆仑造山带的一些特点[J].地球科学,1997,22(4):339-342.YING Hongfu,ZHANG Kexin.Characteristics of the Eastern Kunlun Orogenic Belt[J].Earth Science,1997,22(4):339-342.
赵菲菲,孙丰月,刘金龙.东昆仑马尼特地区片麻状花岗闪长岩锆石U-Pb年代学、地球化学及其构造背景[J].地球科学,2017,42(6):927-940.ZHAO Feifei,SUN Fengyue,LIU Jinlong.Zircon U-Pb Geochronology and Geochemistry of the Gneissic Granodiorite in Manite Area from East Kunlun,with Implications for Geodynamic Setting[J].Earth Science,2017,42(6):927-940.
张雪亭,王秉璋,俞建,等.青海省区域地质概论[M].北京:地质出版社,2007b:1-156.ZHANG Xueting,WANG Bingzhang,YU Jian,et al.A review of regional geology of Qinghai Province[M].Beijing:Geological Publishing House,2007b:1-156.
BELOUSOVAEA,SUZANNE GW,FISHER Y.Igneous Zircon:Trace Element Composition as an Indicator of Source Rock Type[J].Contributions to Mineralogy and Petrology,2002,143:603-622.
IRVINE TN,BARAGAR WRA.A Guide to the Chemical Classification of the Common Volcanic Rocks[J].Canadian Journal of Earth Sciences,1971,8(5):523-548.
LIU Yongsheng,HU Zhaochu,ZONG Keqing,et al.Reappraisement and refinement of zircon 21-Pb isotope and trace element analyses by LA-ICP-MS[J].Chinese Science 22-Bulletin,2010,55(15):1535-1546.
LUDWIG KR.ISOPLOT 3:a User Manual,a Geochronological Toolkit for Microsoft Excel[M].California,Geochronlolgy Centre Berkeley,Special Publication,2003,4:74.
MANIAR PD,PICOLI PM.Tectonic Discrimination of Granitoids[M].Geological Society of American Bulletin,1989,101(5):635-643.
PECCERILLO A,TAYLOR AR.Geochemistry of Eocene Calc-Alkaline Volcanin Rocks from the Kastamonu Area,Northern Turkey[J].Contributions to Mineralogy and Petrology,1976,58(1):63-81.
TAYLOR SR,MCLENNAN SM.The Continental Crust:Its Composition and Evolution[M].Oxford:Blackwell Scientific,1985,312.
WOLF MB,WYLLIE PJ.The Formation of Tonalitic Liquids During the Vapor-absent Partial Melting of Amphibolite at 10kbar[J].Eos,1989,70:506-518.
邓晋福,杨建军,赵海玲,等格尔木-额济纳旗断面走廊域火成岩-构造组合与大地构造演化[J].现代地质,1996,10(3):330-343.DENG Jinfu,YANG Jianjun,ZHAO Hailing,et al.Igneous Petrotectonic Assemblages and Geotectonic Evolution Along go Lmud-Ejinaqi Geosciences Section[J].Geoscience,1996,10(3):330-343.
古凤宝.东昆仑地质特征及晚古生代-中生代构造演化[J].青海地质,1994,2(1):4-14.GU Fengbao.Geological Characteristics of East Kunlun and Tectonic Evolution in Late Palaezoic-Mesozoic Era[J].Qinghai Geology,1994,2(1):4-14.
黄坚.东昆仑晚三叠世构造伸展作用---来自冰沟基性岩墙群的证据[A].武汉:中国地质大学硕士学位论文[D].2013,1-58.HUANG Jian.The Late Triassic Extension of East Kunlun Orogenic Belt:Evidence from Binggou Mafic Dykes[D].China University of Geosciences(Wuhan),2013,1-58.
姜春发,杨经绥,冯秉贵,等.昆仑开合构造[M].北京:地质出版社,1992,224.JIANG Chunfa,YANG Jingsui,FENG Binggui,et al.Opening-Closing Patterns in Kunlun[M].Beijing,Geological Publishing House,1992,224.
李怀坤,耿建珍,郝爽,等.用激光烧蚀多接收器等离子体质谱仪(LA-MC-ICPMS)测定锆石U-Pb同位素年龄的研究[J].矿物岩石地球化学通报,2009,28(增刊):77.LI Huikun,GENG Jianzhen,HAO Shuang,et al.Zircon U-Pb dating technique using LA-MC-ICPMS,Bulletin of Mineralogy[J].Petrology and Geochemistry,2009,28(Supp.):77.
李荣社,计文化,杨永成,等.昆仑山及邻区地质[M].北京:地质出版社,2008.LI Rongshe,JI Wenhua,YANG Yongcheng,et al.Kunlun Mountain and Its AdjacentArea Geology[M].Beijing:Geological Publishing House,2008.
李佐臣,裴先治,刘战庆,等.东昆仑南缘布青山构造混杂岩带哥日卓托闪长岩体年代学、地球化学特征及其地质意义[J].地质学报,2013,87(8):1089-1103.LI Zuochen,PEI Xianzhi,LIU Zhanqing,et al.Geochronology and Geochemistry of the Gerizhuotuo Diorites from the Buqingshan Tectonic Melange Belt in the Southern Margin of East Kunlun and Their Geologic Implications[J].Acta Geologica Sinica,2013,87(8):1089-1103.
刘战庆,裴先治,李瑞保,等.东昆仑南缘布青山构造混杂岩带的地质特征及大地构造意义[J].地质通报,2011a,30(8):1182-1195.LIU Zhanqing,PEI Xianzhi,LI Ruibao,et al.Geological Characteristics of the Buqingshan Tectonic Melange Belt in the Southern Margin of East Kunlun and its Tectonic Implications[J].Geological Bulletin of China,2011a,30(8):1182-1195.
刘战庆.东昆仑南缘布青山构造混杂岩带地质特征及区域构造研究[D].西安:长安大学博士学位论文,2011b:1-180.LIU Zhanqing.Study on the Geological Characteristics and Tectonic of Buqingshan Melanges Belt,the South Margin of East Kunlun Mountains[D].Chang'an University Xi'an,2011b:1-180.
莫宣学,罗照华,邓晋福,等.东昆仑造山带花岗岩及地壳生长[J].高校地质学报,2007,13(3):403-414.MO Xuanxue,LUO Zhaohua,DENG Jinfu,et al.Granitoids and Crustal Growth in the East-Kunlun Orogenic Belt[J].Geological Journal of China Universities 2007,13(3):403-414.
裴先治.勉略-阿尼玛卿构造带的形成演化与动力学特征[A].西安:西北大学博士学位论文[D],2001:1-155.PEI Xianzhi.Geological Evolution and Dynamics of the Mianlue-A'nyemaqen Tectonic Zone,Central China[A].Xi'an:Northwest University[D],2001:1-155.
祁生胜.青海省东昆仑造山带火成岩岩石构造组合与构造演化[A].北京:中国地质大学博士学位论文[D],2015:1-334.QI Shengsheng.Petrotectonic assemblages and tectonic evolution of the East Kunlun orogenic belt in Qinghai Province[A].China University of Geosciences(Beijing)[D].2015:1-334.
魏小林,曾小平,甘承萍,等.东昆仑查干尕诺地区中三叠世中酸性侵入岩地球化学特征及地质意义[J].西北地质,2016,49(2):1-10.WEI Xiaolin,ZENG Xiaoping,GAN Chengping,et al.Geochemistry and Geological Significance of IntermediateAcid Intrusive Rock in the Chaganganuo,Eastern Kunlun[J].Northwestern Geology,2016,49(2):1-10.
吴元保,郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报,2004,49(16):1589-1604.WU Yuanbao,ZHENG Yongfei.Genetic Mineralogy of Zircon and its Restriction on U-Pb Age Interpretation[J].Chinese Science Bulletin,2004,49(16):1589-1604.
许志琴,姜枚,杨经绥,等,青藏高原的地幔结构:地幔羽、地幔剪切带及岩石圈俯冲板片的拆沉[J].地学前缘,2004,11(4):329-343.XU Zhiqin,JIANG Mei,YANG Jingsui,et al.Mantle structure of Qinghai-Tibet Plateau:Mantle plume,mantle shear zone and delamination of lithospheric slab[J].Earth Science Frontiers,2004,11(4):329-343.
殷鸿福,张克信.东昆仑造山带的一些特点[J].地球科学,1997,22(4):339-342.YING Hongfu,ZHANG Kexin.Characteristics of the Eastern Kunlun Orogenic Belt[J].Earth Science,1997,22(4):339-342.
赵菲菲,孙丰月,刘金龙.东昆仑马尼特地区片麻状花岗闪长岩锆石U-Pb年代学、地球化学及其构造背景[J].地球科学,2017,42(6):927-940.ZHAO Feifei,SUN Fengyue,LIU Jinlong.Zircon U-Pb Geochronology and Geochemistry of the Gneissic Granodiorite in Manite Area from East Kunlun,with Implications for Geodynamic Setting[J].Earth Science,2017,42(6):927-940.
张雪亭,王秉璋,俞建,等.青海省区域地质概论[M].北京:地质出版社,2007b:1-156.ZHANG Xueting,WANG Bingzhang,YU Jian,et al.A review of regional geology of Qinghai Province[M].Beijing:Geological Publishing House,2007b:1-156.
BELOUSOVAEA,SUZANNE GW,FISHER Y.Igneous Zircon:Trace Element Composition as an Indicator of Source Rock Type[J].Contributions to Mineralogy and Petrology,2002,143:603-622.
IRVINE TN,BARAGAR WRA.A Guide to the Chemical Classification of the Common Volcanic Rocks[J].Canadian Journal of Earth Sciences,1971,8(5):523-548.
LIU Yongsheng,HU Zhaochu,ZONG Keqing,et al.Reappraisement and refinement of zircon 21-Pb isotope and trace element analyses by LA-ICP-MS[J].Chinese Science 22-Bulletin,2010,55(15):1535-1546.
LUDWIG KR.ISOPLOT 3:a User Manual,a Geochronological Toolkit for Microsoft Excel[M].California,Geochronlolgy Centre Berkeley,Special Publication,2003,4:74.
MANIAR PD,PICOLI PM.Tectonic Discrimination of Granitoids[M].Geological Society of American Bulletin,1989,101(5):635-643.
PECCERILLO A,TAYLOR AR.Geochemistry of Eocene Calc-Alkaline Volcanin Rocks from the Kastamonu Area,Northern Turkey[J].Contributions to Mineralogy and Petrology,1976,58(1):63-81.
TAYLOR SR,MCLENNAN SM.The Continental Crust:Its Composition and Evolution[M].Oxford:Blackwell Scientific,1985,312.
WOLF MB,WYLLIE PJ.The Formation of Tonalitic Liquids During the Vapor-absent Partial Melting of Amphibolite at 10kbar[J].Eos,1989,70:506-518.