内蒙中部四子王旗地区基性侵入岩锆石定年及其意义
Zircon U-Pb dating of basic intrusions in Siziwangqi area of middle Inner Mongolia, China
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摘要: 内蒙中部四子王旗地区横跨华北板块和北方造山带两大构造单元，是研究北方造山带古生代地壳增生演化的重要地区，而出露在该区的古生代基性岩体准确的侵位时代一直无人问津。为此，本文选择该区位于两大构造单元中的三个基性岩体进行锆石LA-ICP-MS U-Pb定年。位于锡林浩特-苏尼特左旗花岗-变质带东延地区的四子王旗北哈达敖包岩体（样品号NM40）明显遭受了后期低级变质作用以及构造挤压作用，其锆石核部发育岩浆成因的震荡环带，给出了508±10Ma(MSWD=1.5)的206Pb/238U加权平均年龄，应代表岩体侵位年龄，反映大洋板片俯冲作用在晚寒武-早奥陶世已经开始；其锆石边部高CL强度无环带的特征暗示受到后期变质作用影响而发生过重结晶作用，加权平均年龄为467±9Ma(MSWD=0.75)，并被解释为变质重结晶年龄下限，可能是弧-陆碰撞事件。位于华北北缘的两个基性岩体（样品号NM54和NM47）的锆石内部特征均显示出岩浆成因的韵律条带，分别给出了331±4Ma（MSWD=1.2）和302±2Ma（MSWD=5）的206Pb/238U加权平均年龄，应代表它们侵位的时代；结合区域研究成果，330~300Ma的岩浆作用很可能是陆-陆碰撞的结果。Abstract: Siziwangqi area of Inner Mongolia sited on northern margin of the North China platform and Paleozoic Xing-Meng orogeny, is of an important district for crustal growth and recycling research. However, many basic intrusions occurring in this area are still in lack of geochronological data. In order to dating of those magmas by LA-ICP-MS, zircons are separated from three representative gabrroic-dioritic intrusions. Zircons from sample NM40 of the Hadaobao diorite which is located at the west extended part of the Xilinhot-Sonidzuoqi granite-metamorphic belt and was undergone greenschist-amphibole facies metamorphism, show double structures of oscillatory zoned cores and none of zoned rims. The cores and rims yield mean 206Pb/238U age of 508±10Ma (MSWD=1.5) and 467±9Ma (MSWD=0.75), respectively. The former age is interpreted to be the time of emplacement and the later one is the lower limit time of regional tectono-metamorphism. Geochronological data obtained from this intrusive indicate that oceanic slab initially subducted at least before 500Ma and collision of arc-continent took place around of 460~400Ma. Samples of NM54 and NM47 were selected from a diorite and gabrrotic intrusive around Siziwangqi County, respectively. Those zircons separated from NM54 and NM47, yield mean ages of 331±5Ma（MSWD=1.3）and 302±2Ma（MSWD=0.24）, respectively. Their ages are proposed to represent emplacement ages and are linked to initial time of continental collision.
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Key words:
- Basic intrusive /
- Zircon U-Pb age /
- Siziwangqi /
- Inner Mongolia
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[1] Cao CZ,Yang FL,Tian CL,Yuan C,The ophiolite in Hegenahan district,Nei Mongol and the position of suture line between Sino-Korean and Siberian plates,北京:地质出版社,1986.
[2] Chen B,Jahn BM,Wilde S,Xu B,Two contrasting Paleozoic magmatic belts in northern Inner Mongolia,China:Petrogenesis and tectonic implications,Tectonophysics,2000.
[3] Chen B,Zhao GC,Wilde S,Subduction-and collision-related granitoids from southern Sonidzuoqi,Inner Mongolia:Isotopic ages and tectonic implications,Geological Review,2001(04).
[4] Hang DW,Huang HZ,Xiao YJ,Xu HM and Jin MY,Permian alkaline granites in central Inner Mongolia and their geodynamic significance,Acta Geologica Sinica,1994(03).
[5] Hoskin PWO,Black LP,Metamorphic zircon formation by solid-state recrystallization of protolith igneous zircon,Journal of Metamorphic Geology,2000.
[6] Liu DY,Jian P,Zhang Q,Zhang FQ Shi YR Shi GH Zhang NQ and Tao H,SHRIMP dating of adakites in the Tulingkai ophiolite,Inner Mongolia:Evidence for the Early Paleozoic subduction,Acta Geologica Sinica,2003(03).
[7] Liu XM,Gao S,Di WCR,Yuan HL and Hu ZC,The simultaneous analysis of U-Pb age and trace elements by 20 um insitu spot beams LA-ICP-MS of single particle zircon,Chinese Science Bulletin,2007(02).
[8] Liu YL,Yang G,Chen JF,Du AD and Xie Z,Re-Os dating of pyrite from Giant Bayan Obo REE-Nb-Fe deposit,Chinese Science Bulletin,2005(24).
[9] Nie FJ,Pei RF,Wu LS,Nd and Sr isotope study on greenschist and granodiorite of the Bainaimiao district,Inner Mongolia,China,Acta Geoscientica Sinica,1995(01).
[10] Sengor AMC,Natal\'in BA,Burtman VS,Evolution of the Altaid tectonic collage and Paleozoie crustal growth in Eurasia,Nature,1993.
[11] Shao JA,Crust Evolution in the Middle Part of the Northem Margin of Sino-Korean Plate,北京:北京大学出版社,1991.
[12] Shi YR,Liu DY,Zhang Q,Jian P Zhang FQ Miao LC Shi GH Zhang LQ and Tao H,SHRIMP dating of diorites and granites in southern Suzuoqi,Inner Mongolia,Acta Geologica Sinica,2004(06).
[13] Shi YR,Liu DY,Zhang Q,Jian P Zhang FQ Miao LC Shi GH Zhang LQ and Tan H,The petrogenesis and SHRIMP dating of the Baiyinbaolidao adakitic rocks in southern Suzuoqi,Inner Mongolia,Acta Petrologica Sinica,2005(01).
[14] Shi YR,Liu DY,Zhang Q,Jian P Zhang FQ Miao LC Shi GH Zhang LQ and Tao H,Zircon SHRIMP dating of K-rich granites in Sonid Zuoqi,central Inner Mongolia,Geological Bulletin of China,2005(05).
[15] Sun SS,McDonough WF,Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes,Geological Society Special Publication,1989.
[16] Tang KD,Tectonic development of Paleozoic foldbelts at the north margin of the Sino-Korean craton,Tectonics,1990(02).
[17] Wang Q,Liu XY,Paleoplate tectonics between Cathaysia and Angaraland in Inner Mongolia of China,Tectonics,1986(07).
[18] Wu FY,Sun DY,Li HM,Jahn BM and Wilde S,A-type granites in northeastern China:Age and geochemical constraints on their petrogenesis,Chemical Geology,2002.
[19] Xiao WJ,Windley BF,Hao J,Zhai MG,Accretion leading to collision and the Permian Solonker suture,Inner Mongolia,China:Termination of the central Asian orogenic belt,Tectonics,2003.
[20] Xu B,Charvel J,Zhang FQ,Primary study on petrology and geochronology of blueschists in Sunidzuoqi,northern Inner Mongolia,Chinese Journal of Geology,2001.
[21] Xu B,Chen B,The structure and evolution of a Middle Paleozoic orogenic belt between the North China and Siberian Blocks,northern Inner Mongolia,China,Science in China(Series D),1997(03).
[22] Zhang C,Liu SW,Han BF,He GQ and Huang BL,SHRIMP U-Pb dating of Dashigou biotite-K-feldspar granites in Shangdu,Inner Mongolia,and its significance,Acta Petrologica Sinica,2007(03).
[23] Zhang HF,Zhou ZG,Liu WC,Li ZZ Zhang YM and Liu CF,Grenvill tecton-thermal event record in the Bainaimiao area,Inner Mongolia,China:Evidence from zircon LA-ICP-MS U-Pb dating of quart monzodiorite dike,Acta Petrologica Sinica,2009(06).
[24] Zhang SH,Zhao Y,Song B,Wu H,The Late Paleozoic gneissic granodiorite pluton in Early Precambrian high-grade metamorphic terrains near Longhua County in northern Hebei Province,North China:Result from zircon SHRIMP U-Pb dating and its tectonic implications,Acta Petrologica Sinica,2004(03).
[25] Zhang SH,Zhao Y,Song B,Carboniferous granitic plutons from the northern margin of the North China Block:Implications for a Late Plaeozoic active continental margin,Journal of the Geological Society(London),2007(02).
[26] Zhang YM,Zhang HF,Liu WC,Zhou ZG,Timing and petrogenesis of the Damiao granodiorite,Siziwangqi,Inner Mongolia,Acta Petrologica Sinica,2009.
[27] Zhu YF,Sun SH,Jiang N,A gold-bearing alkaline pluton in eastern Linxi District,Inner Mongolia:Its geochemistry and metallogenic significance,Resource Geology,2001.
[28] Zhu YF,Sun SH,Gu LB,Ogasawara Y Jiang N and Hanma H,Permian volcanism in the Mongolian orogenic zone,Northeast China:Geochemistry,magma sources and petrogenesis,Geological Magazine,2001(02).
[29] Zhu YF,Sun SH,Mao Q,Zhao G,Geochemistry of the Xilingele Complex,Inner Mongolia:A historic record from Rodinia accretion to continental collision after closure of the Paleo-Asian Ocean,Geological Journal of China Universities,2004(03).
[30] 曹从周,杨芳林,田昌裂,袁朝,内蒙古贺根山地区蛇绿岩和中朝板块和西伯利亚板块之间的缝合带位置,北京:地质出版社,1986.
[31] 陈斌,赵国春,Wilde S,内蒙苏尼特左旗南两类花岗岩的同位素年代学及其构造意义,地质论评,2001(04).
[32] 洪大卫,黄怀曾,肖宜君,徐海明,勒满元,内蒙古中部二叠纪碱性花岗岩及其地球动力学意义,地质学报,1994(03).
[33] 刘敦一,简平,张旗,张福勤,石玉若,施光海,张履桥,陶华,内蒙古图林凯蛇绿岩中埃达克岩SHRIMP测年:早古生洋壳消减证据,地质学报,2003(03).
[34] 柳小明,高山,第五春容,袁洪林,胡兆初,单颗粒锆石的20μm小斑束原位微区LA-ICP-MS U-Pb年龄和微量元素的同时测定,科学通报,2000(02).
[35] 刘玉龙,杨刚,陈江峰,杜安道,谢智,白云鄂博超大型稀土-铌-铁矿床黄铁矿Re-Os定年,科学通报,2005(02).
[36] 聂风军,裴荣富,吴良士,内蒙古白乃庙地区绿片岩和花岗闪长斑岩的钕和锶同位素研究,地球科学-中国地质大学学报,1995(01).
[37] 邵济安,中朝板块北缘中段地壳演化,北京:北京大学出版社,1991.
[38] 石玉若,刘敦一,张旗,简平,张福勤,苗来成,施光海,张履桥,陶华.内蒙古苏左旗地区闪长-花岗岩类SHRIMP年代学,地质学报,2004(06).
[39] 石玉若,刘敦一,张旗,简平,张福勤,苗来成,施光海,张履桥,陶华,内蒙古苏左旗白音宝力道Adakite质岩类成因探讨及其SHRIMP年代学研究,岩石学报,2005(01).
[40] 石玉若,刘敦一,张旗,简平,张福勤,苗来成,施光海,张履桥,陶华,内蒙古中部苏尼特左旗富钾花岗岩锆石SHRIMP U-Pb年龄,地质通报,2005(05).
[41] 徐备,Charvel J,张福勤,内蒙古北部苏尼特左旗蓝片岩岩石学与年代学研究,地质科学,2001.
[42] 徐备,陈斌.内蒙古北部华北板块与西伯利亚板块之间中古生代造山带的结构和演化,中国科学d辑,1997(03).
[43] 张臣,刘树文,韩宝福,何国琦,黄宝玲,内蒙古商都大石沟花岗岩SHRIMP U-Pb年龄及其意义,岩石学报,2007(03).
[44] 张华锋,周志广,刘文灿,李真真,章永梅,柳长峰,内蒙中部白乃庙地区格林威尔岩浆事件记录:石英二长闪长岩脉锆石LA-ICP-MS U-Pb年龄证据,岩石学报,2009(06).
[45] 张拴宏,赵越,宋彪,吴海,冀北隆化早前寒武纪高级变质区内的晚古生代片麻状花岗闪长岩-锆石SHRIMP U-Pb年龄及其构造意义,岩石学报,2004(03).
[46] 章永梅,张华锋,刘文灿,周志广,内蒙古中部四子王旗大庙岩体时代及成因,岩石学报,2009.
[47] 朱永峰,孙世华,毛骞,赵光,内蒙古锡林格勒杂岩的地球化学研究:从Rodinia聚合到古亚洲洋闭合后碰撞造山的历史记录,高校地质学报,2004(03).
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