天山石炭—二叠纪后碰撞花岗岩的Nd、Sr、Pb同位素源区示踪
Discussion of the sources and characteristics on Sr、Nd、Pb isotopes of the Carboniferous to Permian post-collision granites from Tianshan
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摘要: 天山造山带不仅是中亚巨型造山带的组成部分,也是我国西部晚古生代岩浆活动的集中区,蕴含着丰富的古亚洲洋演化的复合地质信息。笔者以探索天山晚古生代花岗岩浆活动的物质来源为目标,采用Sr、Nd、Pb同位素地球化学方法,对该区不同构造单元中具有代表性的花岗岩体进行了全面系统的研究,发现天山不同构造单元中花岗岩Sr、Nd、Pb同位素特征具有明显差异。在与其围岩的同位素特征进行对比研究的基础上,提出了产于不同构造单元石炭—二叠纪花岗岩的可能源区。觉罗塔格石炭—二叠纪裂谷带的晚古生代花岗岩,具有最高的εNd(t)值和最低的(87Sr/86Sr)t值,如,以康古尔石英闪长岩为代表的二叠纪花岗岩的源岩可能是早期泥盆纪大南湖岛弧火山岩(新生地壳);博格达地区的晚石炭—二叠纪花岗岩是早期基性火山岩,亦可能是底侵基性岩部分熔融的产物。中新元古代基底晚石炭—二叠纪裂谷带中花岗岩的源岩亦为同期基性火山岩,但在岩浆演化过程中受到古老基底地壳的混染,导致其εNd(t)值低于石炭—二叠纪裂谷带中花岗岩,而(87Sr/86Sr)t高于石炭—二叠纪裂谷带花岗岩。南天山东段和前寒武系微地块及其边缘中的晚古生代(含个别早古生代花岗岩)花岗岩分别是类似于库米什斜长角闪岩的古老地壳和西天山元古代古老地壳部分熔融的产物,因此它们均具有负的εNd(t)值和异常高的(87Sr/86Sr)t值。上述认识对于了解天山晚古生代区域岩石圈演化及深部过程具有重要意义。
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关键词:
- Sr、Nd、Pb同位素特征 /
- 物质来源 /
- 花岗岩 /
- 石炭—二叠纪 /
- 天山
Abstract: Aiming at the magmatic sources of Late-Palaeozoic granites from Tianshan, this paper comprehensively and systemically discusses the representative granites from various tectonic units of Tianshan according their Sr、Nd、Pb isotopic characteristics, and reveals many obvious differences in these granites. On the basis of comparison with the isotopic characteristics of their wall rocks, the potential sources of these granites are indicated. The Late-Palaeozoic granites in Carboniferous to Permian rift belt of Jueluo tage have the highest ΕNd(t)values and the lowest(87Sr/86Sr)t values,and the island-arc volcanic rocks(juvenile crust)of Devonian Dananhu Formation may be the potential source of Permian granites represented by the quartz diorites in Kangguer;the Late-Carboniferous to Permian granites of Bogda area are probably the products of the partial-melting of the contemporaneous basic volcanic or underp lating basic magma.-
Keywords:
- Sr、Nd、Pb isotope /
- matter source /
- granite /
- Carboniferous to Permian /
- Tianshan
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王作勋,邬继易,吕喜朝,等.天山多旋回构造及成矿[M].北京: 科学出版社,1990.1-217.
何国琦,李茂松,刘德权.中国新疆古生代地壳演化与成矿[M].乌鲁木齐: 新疆人民出版社,1994.1-662.
肖序常,汤耀庆,冯益民,等.新疆北部及邻区大地构造[M].北京: 地质出版社,1992.1-169.
周泰禧,陈江峰.新疆阿拉套山花岗岩类高εNd值的成因探讨[J].地质科学,1996,31(1):72-78.
周泰禧,陈江峰.天山托木尔峰花岗质岩石的同位素地球化学特征[J].岩石学报,2000,16(2):153-160.
赵振华,王中刚,邹天人,等.阿尔泰花岗岩类REE及O、Pb、Sr、Nd同位素组成及成岩类型[A].见: 涂光炽主编,新疆北部固体地球科学新进展[C].北京: 科学出版社,1993,239-266.
赵振华,王中刚,邹天人,等.新疆乌伦古富碱侵入岩成因探讨[J].地球化学,1996,25(3):205-220.
赵振华,白正华,梅厚钧,等.西天山北部晚古生代火山-浅侵位岩浆活动与金、铜、多金属矿床成矿关系的研究[A],国家95攻关项目96-915-03-02专题报告[C],2000,123-130.
赵振华,白正华,熊小林,等.西天山北部晚古生代火山-浅侵位岩浆岩40Ar/39Ar同位素定年.地球化学[J].2003,32(4):317-327.
洪大卫,王式洸,谢锡林,等.兴蒙造山带正εNd值花岗岩的成因和大陆地壳生长[J].地学前缘,2000,7:441-456.
洪大卫,王式洸,谢锡林,等.从中亚正εNd值看超大陆演化和大陆地壳生长的关系[J].地质学报,2003,77(2):203-209.
张传林.新疆康古尔地区花岗岩地质、地球化学特征及地质意义[J].新疆地质,1993,11(1):55-62.
王强,赵振华,熊小林,等.底侵玄武质下地壳的熔融: 来自安徽沙溪Adakite质富钠石英闪长玢岩的证据[J].地球化学,2001,30(4): 353-362.
熊小林,赵振华,白正华,等.兴蒙造山带西天山阿吾拉勒埃答克质岩石成因:Nd和Sr同位素组成的限制[J].岩石学报,2001,17(04):514-522.
张连昌,秦克章,英基丰,等.东天山土屋-延东斑岩铜矿带及其与成矿作用的关系[J].岩石学报,2004,20(02):259-268.
韩宝福,何国琦,王式洸等.新疆北部后碰撞幔源岩浆活动与陆壳纵向生长[J].地质论评,1998,44(4):96-406.
韩宝福,何国琦,王式洸,等.后碰撞幔源岩浆活动、底垫作用及准噶尔盆地基底的性质[J].中国科学(D辑),1999,29(1): 16-21
姜长义,吴文奎,李良辰,等.南天山东段显生宙构造演化[M].北京:地质出版社.2001.1-236.
李文明,任秉琛.东天山中酸性侵入岩浆作用及其地球动力学意义[J].西北地质,2002,35(4): 41-64.
Xia Linqi,Xu Xueyi,Xia Zuchun,et al.Carboniferous Post-collisional Rift Volcanism of the Tianshan Mountains,Northwestern China [J].Acta Geologica Sinica,2003,77(3): 338-360.
Lin-Qi Xia,Xue-Yi Xu,Zu-Chun Xia,et al.Petrogenesis of Carboniferous rift-related volcanic rocks in the Tianshan,northwestern China[J].GSA Bulletin,2004,116(3): 419-433.
Qiao G S.Normalization of isotopic dilution analysis.Scientia Sinica (Series A)[J],1998,31(10): 1263-1268.
Yang J H and Zhou X H.Rb-Sr,Sm-Nd and Pb isotope systematics of pyrite: implications for the age and genesis of lode gold deposits[J].Geology,2001,29: 711-714.
芮宗瑶,刘玉琳,王龙生,等.新疆东天山斑岩铜矿带及其大地构造格局[J].地质学报,2002,76(1):83-94.
李华芹,谢才富,常海亮,等.新疆北部有色贵金属矿床成矿作用年代学[M].北京: 地质出版社.1998.1-335.
车自成,刘良.论伊犁古裂谷[J].岩石学报,12(03):1996,478-489.
顾连兴,胡受奚,于春水,等.博格达陆内碰撞造山带挤压-拉张构造转折期的侵入活动[J].岩石学报,2001,17(02):187-198.
胡霭琴,张国新,李义锋,等.天山造山带基底时代和地壳增生的Nd同位素制约[J].地球科学,1998,29(2): 132-141.
Johannes,Wholtz,Petrogensis and experimental petrology of granitic rocks.Spring-verlag,Berlin,1996.335.
Petford N,Paterson B,McCaffrey K,Pugliese S.Melt infiltration and advection in microdioritic enclaves.Eur.J.Mineral.1996,8: 405-412.
Poli G,Tommasini S,Halliday A N.Trace element and isotopic exchange during acid-basic magma interaction processes.Trans.R.Soc.Edinburgh: Earth Sci.1996,87: 225-232.
陈义兵.西南天山前寒武纪基底时代和特征: 锆石U-Pb年龄和Nd-Sr同位素特征[J].岩石学报,2001,16(1): 34-44.
Hanson G N.The application of trace elements to the petrogenesis of igneous rocks of granitic composition[J].Earth and Planetary Science Letters,1978,38:26-43.
DePaole D J,Wasserburg G J.Petrogenetic mixing models and Nd-Sr isotopic patterns [J].Geochim.Cosmochim.Acta.,1979,43:615-627.
Zindler A,Hart S.Chemical geodynamics[J].Ann.Rev.Earth planet.Sci.,1986,v(14):493-571.
Peccerillo A,Mandefro b,Solomon G,Hambisa G,Beru H,Tesfaye K.Ter Precambrian rocks from Southern Ethiopia: petrology,geochemistry and their interaction with the recent volcanism from the Ethiopian Rift Valley[J].Neues Jahrbuch fur Minereralogie,Abhandlungen,1998,173,237-262.
Peccerillo A,Barberio M R,Yirgu G,Ayalew D,Barbieri M,Wu T W.Relationships between mafic and peralkaline Silicic magmatism in continental rift setting: a petrological,geochemical and isotopic study of the Gedemsa Volcano,central Ethiopian rift[J].Journal of Petrology,2004,44(11): 2003-2032
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