全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
地质学报  2006 

印度大陆与亚洲大陆早期碰撞过程与动力学模型――来自西藏冈底斯新生代火成岩证据

Keywords: 印度―亚洲大陆碰撞,冈底斯岩浆岩,岩石地球化学,大陆俯冲与板片断离,青藏高原

Full-Text   Cite this paper   Add to My Lib

Abstract:

为了揭示青藏高原的形成演化及其隆升历史,本文主要立足于西藏冈底斯带新生代岩浆岩,研究了印度―亚洲大陆碰撞早期阶段的关键岩石记录、详细碰撞过程和深部动力机制。西藏新生代火山-岩浆活动贯穿于主碰撞造山过程的始终,形成规模巨大的冈底斯火成岩浆岩带,其中,火山活动形成著名的林子宗第三纪火山岩系(64~43Ma),岩浆作用则形成3个时间连续、但组合不同的岩浆序列,即:1壳源花岗岩组合(65~50Ma)、2正εNd花岗岩-辉长岩组合(52~47Ma)和3幔源玄武质次火山岩-辉绿岩组合(53~42Ma)。林子宗第三纪火山岩系形成于印度―亚洲大陆对接碰撞之后(~65Ma),不整合覆盖于中生代褶皱构造层之上,中下部钙碱性―高钾钙碱性火山岩显示岛弧/陆缘弧地球化学特征,主要来自于洋壳板片流体交代的地幔楔形区,上部钾玄岩系火山岩则更多地显示壳源特征。壳源花岗岩主要侵位于冈底斯东段腾冲地区,成因类型为白云母过铝花岗岩和富钾钙碱性花岗岩,其高(87Sr/86Sr)i(>0.710)和低εNd(<-7)同位素组成反映其源于碰撞加厚的砂泥质地壳的深熔作用。正εNd值(+2~+5)花岗岩和辉长岩沿冈底斯带成对侵位,花岗岩具有埃达克岩与弧花岗岩过渡特征,其形成有较多的幔源物质贡献;辉长岩正εNd值特征(+2.5~+7.0)、REE平坦型或弱富集型以及亏损大部分不相容元素(Nb,P,Ti,U,Th,LREE)特征,反映软流圈地幔对岩浆形成产生重要贡献。幔源玄武质次火山岩主要为钙碱性岩系,REE平坦型,低(87Sr/86Sr)i(<0.7060)、高εNd(高达+4.3),同位素组成接近于MORB,证明其来源于亏损的软流圈地幔。根据这些构造-岩浆事件的时空分布、岩石组合特征、岩石地球化学以及岩浆演变序列,提出了一个青藏高原大陆碰撞的四阶段演化模式。这个模式强调了170~60Ma,新特提斯洋板片回转,印度大陆与亚洲大陆发生碰撞(≥65Ma),并导致加厚地壳深熔;260~54Ma,印度大陆板片向北陡深俯冲,下地壳缩短加厚,地壳深熔作用持续;353~41Ma,新特提斯洋板片发生断离,并向下拆沉。软流圈物质透过板片断离窗上涌,诱发地幔楔、上覆加厚的镁铁质下地壳熔融;4陡深俯冲的印度大陆板片因特提斯洋板片断离而发生折返,开始低角度俯冲(<40Ma),导致高原内部的陆内俯冲、走滑剪切与地壳缩短,造成冈底斯岩浆间断(40~26Ma)和拉萨地体初始抬升。因此,在青藏高原碰撞造山过程中,主碰撞期造山(65~41Ma)的动力机制主要是印度大陆板片的陡角度俯冲和特提斯洋板片断离,晚碰撞期造山(40~26Ma)的动力机制主要为印度大陆板片的低角度俯冲。

References

[1]  迟效国 李才 金巍.藏北羌塘地区新生代火山作用与岩石圈构造演化[J].中国科学:D辑,2005,35(5):399-410.
[2]  董方浏 侯增谦 高永丰 曾普胜 蒋成兴.滇西腾冲新生代花岗岩:成因类型与构造意义[J].岩石学报,2006,22(4):927~937.
[3]  董国臣 莫宣学 赵志丹 朱弟成 王亮亮 陈涛 李冰.冈底斯岩浆带中段岩浆混合作用:来自花岗杂岩的证据[J].岩石学报,2006,22(4):835~844.
[4]  洪大卫 谢锡林.兴蒙造山带正Σ(Nd,t)值花岗岩的成因和大陆地壳生长[J].地学前缘,:.
[5]  侯增谦 杨竹森 徐文艺 等.青藏高原碰撞造山带:Ⅰ.主碰撞造山成矿作用[J].矿床地质,20068,25(4):337~358.
[6]  侯增谦 孟祥金 曲晓明 高永丰.西藏冈底斯斑岩铜矿带埃达克质斑岩含矿性:源岩相变及深部过程约束[J].矿床地质,2005,24(2):108~121.
[7]  莫宣学 赵志丹 邓晋福 董国臣 周肃 郭铁鹰 张双全 王亮亮.印度―亚洲大陆主碰撞过程的火山作用响应[J].地学前缘,:.
[8]  肖序常 高延林.西藏雅鲁藏布江缝合带中段高压低温变质带的新认识[A]..见:喜马拉雅地质(Ⅱ)[C].北京:地质出版社,1981.1-18.
[9]  岳雅慧 丁林.西藏林周基性岩脉的^40Ar/^39Ar年代学、地球化学及其成因[J].岩石学报,2006,22:855~866.
[10]  Barbarin B.1990.Granitoids:main petrogenetic classification in relation to origin and tectonic setting.Geol.Jour.,25:227~238.
[11]  Besse J,Courtillou V,Possi J P,Westphal M and Zhou X Y.1984.Paleomagnatic estimates of crustal shorting in the Himalayan thrusts and Zangbo suture..Nature,311:621~626.
[12]  Copeland P H,Harrison T M,Kidd W S F,Xu R H,Zhang Y Q.1987.Rapid early Miocene acceleration of uplift in the Gangdese belt,Xizang (southern Tibet),and its bearing on accommodation mechanisms of the India-Asia collision.Earth Planet.Sci.Lett.,86:240~25
[13]  Defant M J,Drummond M S.1990.Derivation of some modern arc magmas by melting of young subducted lithosphere.Nature,34:662~665.
[14]  Ding L,Kapp P,Zhong D L,Deng W M.2003.Cenozoic volcanism in Tibet:Evidence for a transition from oceanic to continental subduction.Journal of Petrology,44:1835~1865.
[15]  Gaetani M,Gaetani E.1991.Multicyclic history of the north India continental margin (northwestern Himalaya).Am.Assoc.Pet.Geol.Bull.,75:1427~1446.
[16]  Harrison T M,Grove M,McKeegan K D,Coath C D,Lovera O M,Le Fort P.1999.Origin and episodic emplacement of the Manaslu intrusive complex,central Himalaya.Jour.Petrol.,40:3~19.
[17]  Hou Z.Q,Gao Y F,Qu X M,Rui Z Y,Mo X X.2004.Origin of adakitic intrusives generated during mid-Miocene east-west extension in southern Tibet.Earth and Planetary Science Letters,220:139~155.
[18]  Hou Z Q,Gao Y F,Qu X M,Rui Z Y,Mo X X.2004.Origin of adakitic intrusives generated during mid-Miocene east-west extension in southern Tibet.Earth and Planetary Science Letters,220:139~155.
[19]  Jaeger J J,Courtillo V,Tapponnier P.1989.Paleontological view of the age of the Deccan traps,the Cretaceous/Tertiary boundary and India-Asia collision.Geology,17:316~319.
[20]  Klootwijk C T,Gee J S,Peirce J W,Smith G M,McFadden P L.1992.An early India-Asia contact:paleomagnetic constrints from Nineyeast Ridge,ODP Leg 121.Geology,20:395~398.
[21]  Leech M,Singh S,Jain A K,Klemperer S L,Manickavasagam R M.2005.The onset of India-Asia continental collision:early,steep subduction required by the timing of UHP metamorphism in the western Himalaya.Earth Planet.Sci.Lett.,234:83~97.
[22]  Mo X X,Hou Z Q,Dong GC,Qu X M,Yang Z M.2006.Possible Contribution of Magma Underplating at 65~45 Ma to Crustal Thickening in south Tibet:Evidence from the Cenozoic Igneous Rocks.Lithos (in press).
[23]  Owens T J,Zandt G.1997.Implications of crustal property variations for models of Tibetan plateau evolution.Nature,387:37~43.
[24]  Ratschbacher L,Frisch W,Liu G,et al.1994.Distributed deformation in southern and western Tibet during and after the India-Asia collision.J.Geophys.Res.,99:19817~19945.
[25]  Scharer E,Xu R H,Allegere C J.1984.U-Pb geochronology of the Gangdese (Transhimalaya) plutonism in the Lhasa-Xizang region,Tibet.Earth Planet.Sci.Lett.,69:311~320.
[26]  Tatsumi Y.1986.Chemical characteristics of fluid phase released from a subduction lithosphere and origin of arc magma:evidence from high-pressure experiments and natural rocks.Jour.Volcano.Geotherm.Res.,29:293~309.
[27]  Zhao W J,Nelson K D,Project INDEPTH Team.1993.Deep seismic reflection evidence for continental underthrusting beneath southern Tibet.Nature,366:557~559.
[28]  邓万明 黄萱.滇西金沙江带北段的富碱斑岩及其与板内变形的关系[J].中国科学:D辑,:.
[29]  高永丰 侯增谦 魏瑞华 等.冈底斯带始新世基性次火山岩Sr-Nd-Pb同位素特征:碰撞后岩浆地幔源区约束[J].岩石学报,2006,22(3):547-557.
[30]  侯增谦 莫宣学 杨志明 王安建 潘桂棠 曲晓明 聂凤军.青藏高原碰撞造山带成矿作用:构造背景、时空分布和主要类型[J].中国地质,2006a,3:348~359.
[31]  侯增谦 潘桂棠 王安建 莫宣学 田世洪 孙晓明 丁林 王二七 高永丰 谢玉玲 曾普胜 秦克章 许继峰 曲晓明 杨志明 杨竹森 费红彩 孟祥金 李振清.青藏高原碰撞造山带:Ⅱ.晚碰撞转换成矿作用[J].矿床地质,2006c,35(5):.
[32]  江万 莫宣学.青藏高原冈底斯带中段花岗岩类及其中铁镁质微粒包体地球化学特征[J].岩石学报,:.
[33]  王成善 李祥辉 等.再论印度―亚洲大陆碰撞的启动时间[J].地质学报,:.
[34]  许继峰 王强.Adakitic火成岩对大陆地壳增厚过程的指示:以青藏北部火山岩为例[J].地学前缘,2003,10:401-406.
[35]  周肃 方念乔 董国臣 赵志丹 刘秀明.西藏林子宗群火山岩的氩―氩同位素测年[J].岩石矿物学杂志,2001,20:317~319.
[36]  Allegre C J and 34 others.1984.Structure and evolution of the Himalaya-Tibet orogenic belt.Nature,307:17~22.
[37]  Barbarin B.1999.A review of the relationships between granitoid types,their origins and their geodynamic environments.Lithos,46:605~626.
[38]  Beck R A,Burbank D W,Sercombe W J,Riley G W,Barndt J K,Shafique N A,Lawrence R D,Khan M A.1995.Stratigraphic evidence for an early collision between northwest India and Asia.Nature,373:55~58.
[39]  DeCelles P G,Gehrels G E,Najiman Y,Martin A,Carter A,Garzanti E.2004.Detrital geochronology and geochemistry of Cretaceous-early Miocene strata of Nepal:implications for timing and diachroneity of initial Himalayan orogenies.Earth Panlet.Sci.Lett.,227:313~330.
[40]  Ding L,Kapp P,Zhong D,Deng W.2005.Paleocene-Eocene record of ophiolite obduction and initial India-Asian collision,south central Tibet.Tectonics,24:1~18.
[41]  Dong G C,Mo X X,Zhao Z D,Wang L L,Chen T.2006.Underplating of mantle-derived magma:Evidence from gabbro-pyroxenite in the Gangdese magmatic belt.Lithos(in review).
[42]  Durr S B.1996.Provenance of Xizang fore-arc basin clastic rocks (Cretaceous,south Tibet).Geol.Soc.Am.Bull.,108:669~684.
[43]  Gao Y F,Hou Z Q,Wei R H.2003.Post-collisional adakitic porphyries in Tibet:Geochemical and Sr-Nd-Pb isotopic constraints on partial melting of oceanic lithosphere and crust-mantle interaction.Sinica Geologica Acta,77:123~135.
[44]  Hou Z Q,Pan G T,Mo X X,et al.2006c.The Metallogensis of the Tibetan collisional orogenic belt:I Mineralization in the late-collisional setting.Mineral Deposits (in Chinese with English abs.).
[45]  Liégeois J P.1998.Some words on the post-collisional magmatism.Lithos,45:ix-xii.
[46]  Jiang W,Mo X X,Zhao C H,Guo T Y,Zhang S Q.1999.Geochemistry of granitoid and its mafic microgranular enclave in Gangdese belt,Qinghai-Xizang plateau.Acta Petrologica Sinica,15:89~97(in Chinese with English abstract).
[47]  Kohn M J,Parkinson C D.2002.Petrologic case for Eocene slab break-off during the Indo-Asian collision.Geology,30:591~594.
[48]  Lee T Y,Lawver L A.1994.Cenozoic plate reconstruction of the South China Sea region.Tectonophyscis,251:85~138.
[49]  Mo X X,Dong G C,Zhao Z D,Guo T Y,Wang L L,Chen T.2005.Timing of magma mixing in the Gangdese magmatic belt during the India-Asian collision:zircon SHRIMP U-Pb dating.Acta Geologica Sinica,79:66~76.
[50]  Patriat P,Achache J.1984.India-Eurasia collision chronology has implications for crustal shortening and driving mechanism of paltes.Nature,311:615~621.
[51]  Rowley D B.1996.Age of initiation of collision between India and Asia:a review of stratigraphic data.Earth Planet.Sci.Lett.,145:1~13.
[52]  Yin A,Harrison T M.2000.Geologic evolution of the Himalayan-Tibetan orogen.Annu.Rev.Earth Planet.Sci.,28:211~280.
[53]  Zindle A.,Hart S R.1986,Chemical geodynamics,Annual Review Earth Planetary Sciences,14:493~573.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133