杨硕;向树元;苏英明;

• 1:中国地质大学(武汉)地球科学学院
• 2:新疆地质调查院
• 3:中国地质大学(武汉)地质调查院
• 4:西安地质矿产勘查开发院

摘要(Abstract)：

林子宗火山岩在冈底斯带上广泛发育,其中帕那组火山岩的形成时代、构造背景和成因都存在一定争议。对林周地区帕那组火山岩进行了年代学和岩石地球化学研究,结果表明,研究区火山岩以流纹岩和英安岩为主,w(SiO2)极高,表现由高钾钙碱性系列向钾玄岩系列过渡的特征。帕那组火山岩微量元素地球化学特征显示LREE、LILE富集,HFSE亏损,Eu负异常,与岛弧火山岩地球化学特征相似。此外,帕那组流纹岩LA-ICP-MS锆石U-Pb年龄为(51.3±0.7)Ma,是目前为止冈底斯带中东段中的最老年龄。帕那组火山岩形成于后碰撞背景之下,其岩浆为地壳源区的部分熔融作用所形成。

关键词(KeyWords)： 帕那组;LA-ICP-MS;锆石U-Pb年龄;岩石地球化学;林周;西藏

Abstract:

Keywords:

基金项目(Foundation): 中国地质调查局项目(1212011221066;1212011121224)

作者(Author): 杨硕;向树元;苏英明;

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DOI:

参考文献(References)：

• [1]莫宣学,赵志丹,邓晋福,等.印度-亚洲大陆主碰撞过程的火山作用响应[J].地学前缘,2003,10(3):135-148.
• [2]Ding Lin,Paul K,Zhong D L,et al.Cenozoic volcanism in Tibet:Evidence for a transition from oceanic to continental subduction[J].J.Petrol.,2003,44(10):1833-1865.
• [3]Mo Xuanxue,Zhao Zhidan,Zhou Su,et al.Evidence for timing of initiation of India-Asia collision from igneous rocks in Tibet[J].EOS Trans.,2002,83:47.
• [4]Coulon C,Maluski H,Bollinges C,et al.Mesozoic and Cenozoic volcanic rocks from central and southern Tibet:39 Ar-40 Ar dating,petrological characteristics and geodynamical significance[J].Earth and Planetary Science Letters,1986,79:281-302.
• [5]Pearce J A,Mei H.Volcanic rocks of the 1985Tibet Geotraverse:Lhasa to Golmud[J].Philosophical Transactions of the Royal Society of London,1988,A327:169-201.
• [6]刘鸿飞.拉萨地区林子宗火山岩系的划分和时代归属[J].西藏地质,1993(2):59-69.
• [7]西藏自治区地质矿产局.西藏自治区区域地质志[M].北京:地质出版社,1993:450-462.
• [8]周肃,莫宣学,董国臣,等.西藏林周盆地林子宗火山岩40 Ar/39 Ar年代格架[J].科学通报,2004,49(20):2095-2103.
• [9]董国臣,莫宣学,赵志丹,等.拉萨北部林周盆地林子宗火山岩层序新议[J].地质通报,2005,24(6):549-557.
• [10]谢克家,曾令森,刘静,等.藏南昂仁县桑桑地区林子宗群火山岩的形成时代和地球化学特征[J].地质通报,2011,30(9):1339-1352.
• [11]梁银平,朱杰,次邛,等.青藏高原冈底斯带中部朱诺地区林子宗群火山岩锆石U-Pb年龄和地球化学特征[J].地球科学:中国地质大学学报,2010,35(2):211-223.
• [12]付文春,康志强,潘会彬.西藏冈底斯带西段狮泉河地区林子宗群火山岩地球化学特征、锆石U-Pb年龄及地质意义[J].地质通报,2014,33(6):850-859.
• [13]周肃,方念乔,董国臣,等.西藏林子宗火山岩氩-氩年代学研究[J].矿物岩石地球化学通报,2001,20(4):317-319.
• [14]董国臣,莫宣学,赵志丹,等.西藏林周盆地林子宗火山岩研究近况[J].地学前缘,2002,9(1):153-153.
• [15]Wan X,Jansa L F,Sarti M.Cretaceous and Tertiary boundary strata in southern Tibet and their implication for India Asia collision[J].Letnaia,2002,35(2):131-146.
• [16]鲍春辉,丁枫,王乾,等.西藏措勤县雄玛地区始新统林子宗群帕那组火山岩地球化学特征及构造背景[J].地质论评,2014,60(2):275-284.
• [17]Garzanti E,Baud A,Mascle G.Sedimentary record of the northward flight of India and its collision with Eurasia(Ladakh Himalaya,India)[J].Geodinamica Acta,1987,1(4/5):297-312.
• [18]Searle M P,Windley B F,Coward M P,et al.The closing of Tethys and the tectonic of Himalaya[J].Geol.Soc.of Am.Bull.,1987,98(6):678-701.
• [19]杨辉,向树元,王欣,等.西藏马乡地区典中组年龄厘定及其构造背景[J].地质科技情报,2013,32(4):89-96.
• [20]李再会,郑来林,李军敏,等.冈底斯中段林子宗火山岩岩石地球化学特征[J].矿物岩石地球化学通报,2008,27(1):20-27.
• [21]黄映聪,杨德明,郑常青,等.西藏林周县扎雪地区林子宗群帕那组火山岩的地球化学特征及其地质意义[J].吉林大学学报:地球科学版,2005,35(5):576-580.
• [22]于枫,李志国,赵志丹,等.西藏冈底斯带中西部措麦地区林子宗火山岩地球化学特征及意义[J].岩石学报,2010,26(7):2217-2225.
• [23]潘桂棠,肖庆辉,陆松年,等.中国大地构造单元划分[J].中国地质,2009,36(1):1-28.
• [24]岳雅慧,丁林.西藏林周基性岩脉的40 Ar/39 Ar年代学、地球化学及其成因[J].岩石学报,2006,22(4):855-866.
• [25]李皓揚,锺孙霖,王彦斌,等.藏南林周盆地林子宗火山岩的时代、成因及其地质意义:锆石U-Pb年龄和Hf同位素证据[J].岩石学报,2007,23(2):493-500.
• [26]周肃.西藏冈底斯岩浆岩带及雅鲁藏布蛇绿岩带关键地段同位素年代学研究[D].北京:中国地质大学(北京),2003.
• [27]向树元,袁晏明,朱耀生,等.西藏1∶5万德庆幅、冈吉幅、白朗幅、格达幅区域地质调查报告[R].武汉:中国地质大学(武汉),2012.
• [28]Andersen T.Correction of common lead in U-Pb analyses that do not report 204Pb[J].Chemical Geology,2002,192(1/2):59-79.
• [29]Ludwig KR.Isoplot/Ex version 2.49:A geochronological toolkit for Microsoft Excel[M].Berkeley:Berkeley Geochronology Center Special Publication,2003:1-56.
• [30]路远发.Geotit:一个用VBA构建的地球化学工具软件包[J].地球化学,2004,33(5):459-464.
• [31]Vavra G,Schmid R,Gebauer D.Internal morphology,habit and U-Th-Pb microanalysis of amphibolite-to-granulite facies zircons:Geochronology of the ivrea zone(Southern Alps)[J].Contributions to Mineralogy and Petrology,1999,134(4):380-404.
• [32]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.
• [33]王乔林.冈底斯西段林子宗群火山岩的地球化学特征及锆石年代学研究[D].北京:中国地质大学(北京),2011.
• [34]Wilson M.A Chemical classification of volcanic rocks based on the total alkali-silica diagram[J].J.of Petrol.,1986,27(3):745-750.
• [35]Peccerillo A R,Taylor S.Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area,Northern Turkey[J].Contributions to Mineralogy&Petrology,1976,58(1):63-81.
• [36]Rickwood P C.Boundary lines within petrologic diagrams which use oxides of major and minor elements[J].Lithos,1989,22(4):247-263.
• [37]Maniar P D,Piccoli P M.Tectonic discrimination of granitoids[J].Geological Society of America Bulletin,1989,101(5):635-643.
• [38]Boynton W V.Chapter 3-Cosmochemistry of the rare earth elements:Meteorite studies[J].Developments in Geochemistry,1984,2(2):63-114.
• [39]Sun S S,McDonough W F.Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes[J].Geological Society London Special Publications,1989,42(1):313-345.
• [40]西藏地质矿产局区域地质调查大队.西藏1∶20万拉萨幅区域地质调查报告[R].拉萨:西藏地质矿产局区域地质调查大队,1991.
• [41]西藏地质矿产局区域地质调查大队.西藏1∶20万谢通门幅、南木林幅区域地质调查报告[R].拉萨:西藏地质矿产局区域地质调查大队,1996.
• [42]Pearce J A.Sources and settings of granitic rocks[J].Episodes,1996,19:120-125.
• [43]莫宣学,赵志丹,周肃,等.印度-亚洲大陆碰撞的时限[J].地质通报,2007,26(10):1240-1244.
• [44]Harris N B W,Pearce J A,Tindle A G.Geochemical characteristic of collision-zone magmatism[J].Geological Society of London,1986,19(5):67-81.
• [45]Hugh R Rollison.岩石地球化学[M].杨学明,杨晓勇,陈双喜,译.合肥:中国科技大学出版社,2000.
• [46]赵志丹,莫宣学,张双全,等.西藏中部乌郁盆地碰撞后岩浆作用:特提斯洋壳俯冲再循环的证据[J].中国科学D辑,2001(S1):20-26.
• [47]Taylor S R,McLennan S M.The continental crust:Its composition and evolution[J].Physics of the Earth and Planetary Interiors,1986,42:196-197.
• [48]陈德潜,陈刚.实用稀土地球化学[M].北京:冶金工业出版社,1990.
• [49]Allegre C J,Minster J F.Quantitative models of trace element behavior in magmatic processes[J].Earth&Planetary Science Letters,1978,38(1):1-25.
• [50]Condie K C.Mantle plume and their record in earth history[M].London:Cambridge University Press,2001.
• [51]Ding L,Paul K,Zhong D L,et al.Cenozoic volcanism in Tibet:Evidence for a transition from oceanic to continental subduction[J].J.Petrol.,2003,44(10):1833-1865.
• [52]Rollison H R.Using geochemical data:Evaluation,presentation,interpretation[M].London:Longman Group UK Ltd,1993.