青藏高原东北缘岩石圈变形及其机理
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摘要
为了解青藏高原东北缘岩石圈变形特征,进一步研究该地区地壳运动的壳-幔耦合机理,本文通过处理分析该地区1999～2007年多期GPS观测数据、1972～2000年水准测量数据和1992年及2007年相对重力测量资料,获得了该区域地壳水平运动速度场、较长时间段的垂直形变场和相对重力变化场.分析发现青藏高原东北缘东西部的变化特征存在明显差异:西部以北东向地壳缩短运动为主,而东部以顺时针旋转为主;东部以地壳隆升为主,速率在2.1 mm/a左右,而西部隆升的速率小于1 mm/a;相对重力变化则表现为在整体增大的背景下东部升高速率较大,平均为9.0×10~(-8)m·s~(-2)·a~(-1) ,而西部较小,平均值为3.1×10~(-8)m·s~(-2)·a~(-1).我们还发现,地壳不同变形形式的转换不是渐变的,而是发生在较窄的一个转换带内,这个转换带的整体走向为NEE,北部位于金昌与武威之间,中部在祁连山东部、门源以西,南部位于德令哈以东青海湖以西.最后结合前寒武纪构造格架、重力均衡异常资料和地震SKS分裂结果对形成这种运动态势的机理进行了探讨,我们认为岩石圈物质侧向流动、岩石圈结构及壳-幔耦合方式差异可能是导致东部与西部岩石圈变形差异主要动因.
In order to investigate the features of lithosphere and study the deformation mechanism of crust-mantle coupling in northeastern margin of Tibet plateau,we have processed the GPS data observed from 1999 to 2007,leveling data observed in 1972～2000 and relative gravity data in 1992 and 2007,we have got the horizontal velocity field,long time crustal vertical rate field and gravity variation field in northeastern margin of Qinghai-Tibet plateau.We found that the deformation style in the east is different from that in the west.In the west the crust moves toward NE and shortens mainly,but in the east it rotates clockwise mainly.As for the vertical deformation the eastern part rises with an average rate of 2.1 mm/a,the western part rises slowly with a rate less than 1.0 mm/a.The gravity in the east increases greatly with a rate of 9. 0×10~(-8)m · s~(-2)· a~(-1),more than that in the west with a rate of 3.1 × 10~(-8) m · s~(-2)· a~(-1).The style of deformation variation is not gradual but occurs in a transition belt.This belt is orientated in NEE.Its north section is between Jinchan and Wuwei in Gansu province,the middle is in the east of eastern Qilian mountain and the west of Menyuan in Qinghai province,The south section is in the east of Delingha and the west of Qinghai Lake.Furthermore,by use of Precambrian tectonic framework,gravity anomaly data and seismic SKS splitting result,the lithosphere deformation mechanism is studied.We infer that the main reasons for the difference of lithosphere deformation are probably the lateral flow,of lithosphere material and the differences in lithosphere structures and crust-mantle coupling.
In order to investigate the features of lithosphere and study the deformation mechanism of crust-mantle coupling in northeastern margin of Tibet plateau,we have processed the GPS data observed from 1999 to 2007,leveling data observed in 1972～2000 and relative gravity data in 1992 and 2007,we have got the horizontal velocity field,long time crustal vertical rate field and gravity variation field in northeastern margin of Qinghai-Tibet plateau.We found that the deformation style in the east is different from that in the west.In the west the crust moves toward NE and shortens mainly,but in the east it rotates clockwise mainly.As for the vertical deformation the eastern part rises with an average rate of 2.1 mm/a,the western part rises slowly with a rate less than 1.0 mm/a.The gravity in the east increases greatly with a rate of 9. 0×10~(-8)m · s~(-2)· a~(-1),more than that in the west with a rate of 3.1 × 10~(-8) m · s~(-2)· a~(-1).The style of deformation variation is not gradual but occurs in a transition belt.This belt is orientated in NEE.Its north section is between Jinchan and Wuwei in Gansu province,the middle is in the east of eastern Qilian mountain and the west of Menyuan in Qinghai province,The south section is in the east of Delingha and the west of Qinghai Lake.Furthermore,by use of Precambrian tectonic framework,gravity anomaly data and seismic SKS splitting result,the lithosphere deformation mechanism is studied.We infer that the main reasons for the difference of lithosphere deformation are probably the lateral flow,of lithosphere material and the differences in lithosphere structures and crust-mantle coupling.
引文
[1] 张培震,甘卫军,沈正康.中国大陆现今构造作用的地块运动 和连续变形耦合模型.地质学报.2005,79(6) :750～755 Zhang P Z,Gan W J,Shen Z K,et al.A coupling model of rigid-block movement and continuous deformation:patterns of the present day deformation of China's continent and its vicinity.Acta Geologica Sinic (in Chinese),2005,79 (6) :750--755
[2] 向宏发,虢顺民,陈志泰等.祁连块体的旋转运动与区域地震活动的时空分布.见:中法合作活断层对比研究.北京:地震出版社,1993． 84～93 Xiang H F,Guo S M,Chen Z T,et al.Rotational movement of the Qilian block and the regional time-space distribution of earthquakes.In:Comparison Studying of Active Faults on China France Cooperation(in Chinese).Beijing:Seismological Press,1993． 84--93
[3] 徐锡伟,程国良,马杏垣等.华北及其邻区旋转模式和块体动力来源.中国地质大学学报-地球学.1994,19(2) :129～138 Xu X W,Cheng G L,Ma X Y,et al.Rotation model and dynamics of blocks in north China and its adjacent areas.Journal of China University of Geosciences (Earth Science) (in Chinese),1994,19(2) :129-138
[4] 国家地震局地质研究所和兰州地震研究所.祁连山-河西走廊活动断裂系.北京:地震出版社,1993 Geological Institute of State Seismological Bureau & Lanzhou Seismological Institute.Active Fault Systems of Qilian Mountain Hexi Corridor Region (in Chinese).Beijin:Seismological Press,1993
[5] 鄂尔多斯块体周边活动断裂系研究组,国家地震局.鄂尔多斯块体周边活动断裂系.北京:地震出社.1988 Research Group of Active Fault System Along the Border of Erdos Block,State Seismological Bureau.Active Fault System Along the Border of Erdos Block.Beijing:Seismological Press,1988
[6] 江在森,张希,崔笃信等.青藏块体东北缘近期水平运动与形变.地球物理学报,2001,44(5) :639～644 Jiang Z S,Zhang X,Cui D X,et al.Recent horizontal movement and deformation in the northeast margin of Qinghai-Tibet block.Chinese J.Geophys.(in Chinese),2001,44(5) :639-644
[7] 王庆良,王文萍,崔笃信.青藏块体东北缘现今地壳运动.大地测量与地球动力学,2002,22(4) :12～16 Wang Q L,Wang W P,Cui D X.The nowadays crustal movement in northeastern margin of Qinghai-Tibet block.Journal of Geodesy and Geodynamics (in Chinese),2002,22(4) :12-16
[8] 崔笃信,王庆良,王文萍等.片青块体东西部运动分界带的确定.大地测量与地球动力学,2007． 27(1) :24～30 Cui D X,Wang Q L,Wang W P,etal.Determination of movement boundary belt of Gansu-Qinghai block.Journal of Geodesy and Get,dynamics (in Chinese),2007,27(1) :24-30
[9] 王敏,沈正康,牛之俊等.现今中国大陆地壳运动与活动块体模型.中国科学(D辑),2006,33(增刊):22～31 Wang M,Shen Z K,Niu Z J,et al.The active Block model of crustal movement in China mainland.Science in China (Series D-Earth Sciences) (in Chinese),2003,33(Suppl.):22-31
[10] 祝意青,胡斌,李辉等.用双三次样条函数模拟青藏高原东北缘重力场动态图像.中国地震,2005,21(2) :165～171 Zhu Y Q,Hu B,Li H,et al.Gravity dynamic image of the northeastern edge of Tibet plateau by using hi-cubic spline interpolation function.Earthquake Research in China (in Chinese),2005,21(2) :165-171
[11] 张四新.江在森,王双绪等.北祁连-河西地区垂直形变场演化与地震活动关系研究.大地测量与地球动力学,2001,21(2) :70～76 Zhang S X,Jiang Z S,Wang S X,et al.Study on evolution of the vertical deformation field and its relationship to seismic activity in Qilian mountain-Hexi corridor.Journal of Geodesy and Geodynamics (in Chinese),2001,21(2) :70-76
[12] Zhang P Z,Shen Z K,Wang M,et al.Continuous deformation of the Tibetan Plateau from global positioning system data.Geology,2004,32:809-812
[13] Shen Z K,Lu J N,Wang M,et al.Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau.Journal of Geophysical Research,2005,110 (B11409) ,1-17
[14] 张培震,沈正康,王敏等.青藏高原及周边现今构造变形的运动学.地震地质,2004,26(3) :368～376 Zhang P Z,Shen Z K,Wang M,et al.Kinematics of present-day tectonic deformation of the Tibetan plateau and its vicinities.Earthquake and Geology (in Chinese),2004,26(1) :368-376
[15] 杨国华,李延兴,韩月萍等.中国西部地壳现今变形特征及其机制探讨.测绘学报,2002,31(4) :292～299 Yang G H,Li Y X,Han Y P,et al.Characteristics of present-day crustal deformation in western China and discussion of its mechanism. Acta Geodaetica et Cartographica Sinica (in Chinese),2002,31(4) :292-299
[16] Flesch L M,Holt W E,Silver P G,et al.Constraining the extent of crust-mantle coupling in Central Asia using GPS,geologic,and shear-wave splitting data.Earth and Planetary Science Letters,2005,238:248-268
[17] Flesch L M,Haines A J,Holt W E.Dynamics of the India-Eurasia collision zone.Journal of Geophysical Research,2005,106:16435-16460
[18] Sol S,Melzer A,B(u|¨)rgmann R,et al.Geodynamics of the southeastern Tibetan Plateau from seismic anisotropy and geodesy.Geology,2007,35(6) :563-566
[19] 崔笃信,王庆良,王文萍.青藏块体东北缘地壳水平运动状态.大地测量与地球动力学,2004,24(3) :29～33 Cui D X,Wang Q L,Wang W P.Crustal horizental movement state of northeastern margin of Qinghai-Tibit block.Journal of Geodesy and Geodynamics (in Chinese),2004,24(3) :29-33
[20] 陈杰,陈宇坤,丁国瑜等.2001年昆仑山口西8． 1级地震地 表破裂带.第四纪研究,23(6) :629～639 Chen J,Chen Y G,Ding G Y,et al.Surface rupture zones of the 2001 earthquake M_s8． 1 west of Kunlun Pass,northern Qinghai-Xizang Plateau.Quaternary Sciences (in Chinese),2003,23(6) :629-639
[21] 陶本藻.自由网平差与变形分析.武汉:武汉测绘科技大学出版社,2001 Tao B Z.Adjustment of Free net and Analysis of Deformation. Beijing:Wuhan Technical University of Surveying and Map Press,2001
[22] 中国地震局《中国岩石圈动力学图集》编委会.中国岩石圈动力学图集.北京:中国地图出版社,1989 Editorial Board for Lithospheric Dynamics Atlas of China of State Seismological Bureau.Lithospheric Dynamics Atlas of China (in Chinese).Beijing:China Cartographic Publishing House,1989
[23] 王椿镛,常利军,吕智勇等.青藏高原东部上地幔各向异性及相关的壳幔耦合型式.中国科学(D辑),2007,37(4) :495～503 Wang C Y,Chang L J,L(u|¨) Z Y,et al.Seismic anisotropy of upper mantle in eastern Tibetan Plateau and related crustmantle coupling pattern.Science in China (Series D-Earth Sciences) (in Chinese),2007,37(4) :495-503
[24] 罗艳,黄忠贤,彭艳菊.中国大陆及邻区SKS波分裂研究.地球物理学报,2004,47(5) :812～821 Luo Y,Huang Z X,Peng Y J,et al.A study on SKS wave splitting beneath the China mainland and adjacent regions.Chinese J.Geophys.(in Chinese),2004,47(5) :812-821
[25] 常利军,王椿镛,丁志峰.云南地区SKS波分裂研究.地球物理学报,2006,49(1) :197～204 Chang L J,Wang C Y,Ding Z F.A study of SKS splitting beneath the Yunnan region.Chinese J.Geophys.(in Chinese),2006,49(1) :197-204
[26] 许厚泽.重力观测在中国地壳运动观测网络中的作用.大地测量与地球动力学,2003,23(3) :1～3 Xu H Z.Function of gravimetry in CMONOC.Journal of Geodesy and Geodynamics (in Chinese),2003,23(3) :1-3
[27] 罗岚,李辉.伴随地壳运动的重力变化研究及进展.国际地震动态,1996,(6) :28～30 Luo L,Li H.The study of gravity variation with crustal movement.Recent Developments in World Seismology (in Chinese),1996,(6) :28-30
[28] 沈正康,王敏,甘卫军等.中国大陆现今构造应变率场及其动力学成因研究.地学前沿,2003,10(特刊):93～100 Shen Z K,Wang M,Gan W J,et aI.Contemporary tectonic strain rate field of Chinese continent and its geodynamic implications.Earth Science Frontier (in Chinese),2003,10(Special):93-100
[29] 黄建平,傅容珊,郑勇.地幔对流拖曳力对中国大陆岩石层变形的影响.地球物理学报,2008,51(4) :1048～1057 Huang J P,Fu R S,Zheng Y,et al.The influence of mantle convection to the lithosphere deformation of China Mainland.Chinese J.Geophys.(in Chinese),2008,51(4) :1048-1057
[30] 王泽利,何樵登,孟令顺.青藏高原北缘深部地壳结构特征及其形成机制探讨.世界地质,2002,21(2) :105～110 Wang Z L,He J D,Meng L S.The crustal structure of the northern margin of Qinghai-Tibet plateau and its genetic analysis.World Geology (in Chinese),2002,21 (2) :105-110
[31] 《中国岩石圈动力学图集》编委会.中国岩石圈动力学概论.北京:地震出版社,1991 Editorial Board for Lithospheric Dynamics Atlas of China of State Seismological Bureau.Lithospheric Dynamics Compendium of China (in Chinese).Beijing:Seismological Press,1991
[32] 李勇,徐公达,周荣军.龙门山均衡重力异常及其对青藏高原东缘山脉地壳隆升的约束.地质通报,2005,24(4) :1163～1167 Li Y,Xu G D,Zhou R J,et al.Isostatic gravity anomalies in the Longmen Mountains and their constraints on the crustal uplift below the mountains on the eastern margin of the Qinghai-Tibet Plateau.Geological Bulletin of China (in Chinese),2005,24(12) :1162-1167
[2] 向宏发,虢顺民,陈志泰等.祁连块体的旋转运动与区域地震活动的时空分布.见:中法合作活断层对比研究.北京:地震出版社,1993． 84～93 Xiang H F,Guo S M,Chen Z T,et al.Rotational movement of the Qilian block and the regional time-space distribution of earthquakes.In:Comparison Studying of Active Faults on China France Cooperation(in Chinese).Beijing:Seismological Press,1993． 84--93
[3] 徐锡伟,程国良,马杏垣等.华北及其邻区旋转模式和块体动力来源.中国地质大学学报-地球学.1994,19(2) :129～138 Xu X W,Cheng G L,Ma X Y,et al.Rotation model and dynamics of blocks in north China and its adjacent areas.Journal of China University of Geosciences (Earth Science) (in Chinese),1994,19(2) :129-138
[4] 国家地震局地质研究所和兰州地震研究所.祁连山-河西走廊活动断裂系.北京:地震出版社,1993 Geological Institute of State Seismological Bureau & Lanzhou Seismological Institute.Active Fault Systems of Qilian Mountain Hexi Corridor Region (in Chinese).Beijin:Seismological Press,1993
[5] 鄂尔多斯块体周边活动断裂系研究组,国家地震局.鄂尔多斯块体周边活动断裂系.北京:地震出社.1988 Research Group of Active Fault System Along the Border of Erdos Block,State Seismological Bureau.Active Fault System Along the Border of Erdos Block.Beijing:Seismological Press,1988
[6] 江在森,张希,崔笃信等.青藏块体东北缘近期水平运动与形变.地球物理学报,2001,44(5) :639～644 Jiang Z S,Zhang X,Cui D X,et al.Recent horizontal movement and deformation in the northeast margin of Qinghai-Tibet block.Chinese J.Geophys.(in Chinese),2001,44(5) :639-644
[7] 王庆良,王文萍,崔笃信.青藏块体东北缘现今地壳运动.大地测量与地球动力学,2002,22(4) :12～16 Wang Q L,Wang W P,Cui D X.The nowadays crustal movement in northeastern margin of Qinghai-Tibet block.Journal of Geodesy and Geodynamics (in Chinese),2002,22(4) :12-16
[8] 崔笃信,王庆良,王文萍等.片青块体东西部运动分界带的确定.大地测量与地球动力学,2007． 27(1) :24～30 Cui D X,Wang Q L,Wang W P,etal.Determination of movement boundary belt of Gansu-Qinghai block.Journal of Geodesy and Get,dynamics (in Chinese),2007,27(1) :24-30
[9] 王敏,沈正康,牛之俊等.现今中国大陆地壳运动与活动块体模型.中国科学(D辑),2006,33(增刊):22～31 Wang M,Shen Z K,Niu Z J,et al.The active Block model of crustal movement in China mainland.Science in China (Series D-Earth Sciences) (in Chinese),2003,33(Suppl.):22-31
[10] 祝意青,胡斌,李辉等.用双三次样条函数模拟青藏高原东北缘重力场动态图像.中国地震,2005,21(2) :165～171 Zhu Y Q,Hu B,Li H,et al.Gravity dynamic image of the northeastern edge of Tibet plateau by using hi-cubic spline interpolation function.Earthquake Research in China (in Chinese),2005,21(2) :165-171
[11] 张四新.江在森,王双绪等.北祁连-河西地区垂直形变场演化与地震活动关系研究.大地测量与地球动力学,2001,21(2) :70～76 Zhang S X,Jiang Z S,Wang S X,et al.Study on evolution of the vertical deformation field and its relationship to seismic activity in Qilian mountain-Hexi corridor.Journal of Geodesy and Geodynamics (in Chinese),2001,21(2) :70-76
[12] Zhang P Z,Shen Z K,Wang M,et al.Continuous deformation of the Tibetan Plateau from global positioning system data.Geology,2004,32:809-812
[13] Shen Z K,Lu J N,Wang M,et al.Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau.Journal of Geophysical Research,2005,110 (B11409) ,1-17
[14] 张培震,沈正康,王敏等.青藏高原及周边现今构造变形的运动学.地震地质,2004,26(3) :368～376 Zhang P Z,Shen Z K,Wang M,et al.Kinematics of present-day tectonic deformation of the Tibetan plateau and its vicinities.Earthquake and Geology (in Chinese),2004,26(1) :368-376
[15] 杨国华,李延兴,韩月萍等.中国西部地壳现今变形特征及其机制探讨.测绘学报,2002,31(4) :292～299 Yang G H,Li Y X,Han Y P,et al.Characteristics of present-day crustal deformation in western China and discussion of its mechanism. Acta Geodaetica et Cartographica Sinica (in Chinese),2002,31(4) :292-299
[16] Flesch L M,Holt W E,Silver P G,et al.Constraining the extent of crust-mantle coupling in Central Asia using GPS,geologic,and shear-wave splitting data.Earth and Planetary Science Letters,2005,238:248-268
[17] Flesch L M,Haines A J,Holt W E.Dynamics of the India-Eurasia collision zone.Journal of Geophysical Research,2005,106:16435-16460
[18] Sol S,Melzer A,B(u|¨)rgmann R,et al.Geodynamics of the southeastern Tibetan Plateau from seismic anisotropy and geodesy.Geology,2007,35(6) :563-566
[19] 崔笃信,王庆良,王文萍.青藏块体东北缘地壳水平运动状态.大地测量与地球动力学,2004,24(3) :29～33 Cui D X,Wang Q L,Wang W P.Crustal horizental movement state of northeastern margin of Qinghai-Tibit block.Journal of Geodesy and Geodynamics (in Chinese),2004,24(3) :29-33
[20] 陈杰,陈宇坤,丁国瑜等.2001年昆仑山口西8． 1级地震地 表破裂带.第四纪研究,23(6) :629～639 Chen J,Chen Y G,Ding G Y,et al.Surface rupture zones of the 2001 earthquake M_s8． 1 west of Kunlun Pass,northern Qinghai-Xizang Plateau.Quaternary Sciences (in Chinese),2003,23(6) :629-639
[21] 陶本藻.自由网平差与变形分析.武汉:武汉测绘科技大学出版社,2001 Tao B Z.Adjustment of Free net and Analysis of Deformation. Beijing:Wuhan Technical University of Surveying and Map Press,2001
[22] 中国地震局《中国岩石圈动力学图集》编委会.中国岩石圈动力学图集.北京:中国地图出版社,1989 Editorial Board for Lithospheric Dynamics Atlas of China of State Seismological Bureau.Lithospheric Dynamics Atlas of China (in Chinese).Beijing:China Cartographic Publishing House,1989
[23] 王椿镛,常利军,吕智勇等.青藏高原东部上地幔各向异性及相关的壳幔耦合型式.中国科学(D辑),2007,37(4) :495～503 Wang C Y,Chang L J,L(u|¨) Z Y,et al.Seismic anisotropy of upper mantle in eastern Tibetan Plateau and related crustmantle coupling pattern.Science in China (Series D-Earth Sciences) (in Chinese),2007,37(4) :495-503
[24] 罗艳,黄忠贤,彭艳菊.中国大陆及邻区SKS波分裂研究.地球物理学报,2004,47(5) :812～821 Luo Y,Huang Z X,Peng Y J,et al.A study on SKS wave splitting beneath the China mainland and adjacent regions.Chinese J.Geophys.(in Chinese),2004,47(5) :812-821
[25] 常利军,王椿镛,丁志峰.云南地区SKS波分裂研究.地球物理学报,2006,49(1) :197～204 Chang L J,Wang C Y,Ding Z F.A study of SKS splitting beneath the Yunnan region.Chinese J.Geophys.(in Chinese),2006,49(1) :197-204
[26] 许厚泽.重力观测在中国地壳运动观测网络中的作用.大地测量与地球动力学,2003,23(3) :1～3 Xu H Z.Function of gravimetry in CMONOC.Journal of Geodesy and Geodynamics (in Chinese),2003,23(3) :1-3
[27] 罗岚,李辉.伴随地壳运动的重力变化研究及进展.国际地震动态,1996,(6) :28～30 Luo L,Li H.The study of gravity variation with crustal movement.Recent Developments in World Seismology (in Chinese),1996,(6) :28-30
[28] 沈正康,王敏,甘卫军等.中国大陆现今构造应变率场及其动力学成因研究.地学前沿,2003,10(特刊):93～100 Shen Z K,Wang M,Gan W J,et aI.Contemporary tectonic strain rate field of Chinese continent and its geodynamic implications.Earth Science Frontier (in Chinese),2003,10(Special):93-100
[29] 黄建平,傅容珊,郑勇.地幔对流拖曳力对中国大陆岩石层变形的影响.地球物理学报,2008,51(4) :1048～1057 Huang J P,Fu R S,Zheng Y,et al.The influence of mantle convection to the lithosphere deformation of China Mainland.Chinese J.Geophys.(in Chinese),2008,51(4) :1048-1057
[30] 王泽利,何樵登,孟令顺.青藏高原北缘深部地壳结构特征及其形成机制探讨.世界地质,2002,21(2) :105～110 Wang Z L,He J D,Meng L S.The crustal structure of the northern margin of Qinghai-Tibet plateau and its genetic analysis.World Geology (in Chinese),2002,21 (2) :105-110
[31] 《中国岩石圈动力学图集》编委会.中国岩石圈动力学概论.北京:地震出版社,1991 Editorial Board for Lithospheric Dynamics Atlas of China of State Seismological Bureau.Lithospheric Dynamics Compendium of China (in Chinese).Beijing:Seismological Press,1991
[32] 李勇,徐公达,周荣军.龙门山均衡重力异常及其对青藏高原东缘山脉地壳隆升的约束.地质通报,2005,24(4) :1163～1167 Li Y,Xu G D,Zhou R J,et al.Isostatic gravity anomalies in the Longmen Mountains and their constraints on the crustal uplift below the mountains on the eastern margin of the Qinghai-Tibet Plateau.Geological Bulletin of China (in Chinese),2005,24(12) :1162-1167
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