西藏东部地区层析成像及东南部裂谷成因讨论
摘要
利用西藏东部南迦巴瓦地区的51个临时地震台站所记录的169个远震事件,从中提取出4767条P波射线,通过反演计算得到了西藏东部地壳和上地幔的P波速度结构.水平剖面显示,在西藏东南部裂谷附近从近地表到250km的深度范围均表现为低速异常;从纵剖面结果看,这个低速异常非垂直地向下延伸到约400km深度.综合分析认为,此低速异常可能意味着地幔高温物质上涌,从而为该区裂谷成因的探讨提供了地震学的证据;在此低速异常的东侧出现明显的高速异常,深度从40km延伸到200km,该高速异常可能是大陆闭合遗留的产物,并非俯冲的印度板块;在250～400km的深度范围内,嘉黎断裂以北为低速异常区,以南为高速异常区.该高速异常可能反映了印度板块的北部边界,并在此发生了拆沉.同时表明,在西藏东部印度板块的俯冲未超过嘉黎断裂.
引文
1Yin A,Harrison T M.Geologic evolution of the Himalayan-Tibetan orogen.Annu Rev Earth Planet Sci,2000,28:211-280
2吴中海,张永双,胡道功,等.西藏错那-拿日雍错地堑的第四纪正断层作用及其形成机制探讨.第四纪研究,2008,28:232-242
3Jimenez-Munt I,Platt J P.Influence of mantle dynamics on the topographic evolution of the Tibetan Plateau:Results from numerical modeling.Tectonics,2006,25,doi:10.1029/2006TC001963
4Zhao J M,Yuan X H,Liu H B,et a1.The boundary between the Indian and Asian tectonic plates below Tibet.Proc Natl Acad Sci USA,2010.107:11229-11233
5Tilmann F,Ni J,Team I I S.Seismic imaging of the downwelling Indian lithosphere beneath central Tibet.Science,2003,300:1424-1427
6Nabelek J,Hetenyi G,Vergne J,et a1.Underplating in the Himalaya—Tibet Collision Zone Revealed by the Hi-CLIMB Experiment.Science,2009,325:1371-1374
7苏伟,王椿镛,黄忠贤.青藏高原及邻区的Rayleigh面波的方位各向异性.中国科学D辑:地球科学,2008,38:674-682
8Priestley K,Debayle E,McKenzie D,et a1.Upper mantle structure of eastern Asia from multimode surface waveform tomography.J Geophys Res,2006,111,doi:10.1029/2005JB004082
9Zhou H W,Murphy M A.Tornographic evidence for wholesale underthrusting of India beneath the entire Tibetan plateau.J Asian Earth Sci,2005,25:445-457
10Rapine R,Tilmann F,West M,et al.Crustal structure of northern and southern Tibet from surface wave dispersion analysis.J Geophys Res,2003,108,doi:10.1029/2001JB000445
11Lebedev S,van der Hilst R D.Global upper-mantle tomography with the automated multimode inversion of surface and S-wave forms.Geophys J Int,2008,173:505-518
12Chen Y,Badal J,Zhang Z J.Radial anisotropy in the crust and upper mantle beneath the Qinghai—Tibet Plateau and surrounding regions.J Asian Earth Sci.2009.36:289-302
13Zhang Z J,Klemperer S.Crustal structure of the Tethyan Himalaya,southern Tibet:New constraints from old wide-angle seismic data.Geophys J Int,2010,181:1247-1260
14Zhang Z J,Klemperer S L.West-east variation in crustal thickness in northern Lhasa block,central Tibet,from deep seismic sounding data.J Geophys Res,2005,110,doi:10.1029/2004JB003139
15Kennett B L N,Engdahl E R.Traveltimes for global earthquake location and phase identification.Geophys J Int,1991,105:429-465
16江国明,赵大鹏,张贵宾.远震层析成像中的地壳校正研究及应用.地球物理学报,2009,52:1508-1514
17Zhao D P,Hasegawa A,Horiuchi S.Deep structure of Japan subduction zone as derived from local,regional,and teleseismic events.J Geophys Res,1994,99:22313-22329
18Paige C C,Saunders M A.LSQR:An Algorithm for Sparse Linear-Equations and Sparse Least-Squares.ACM Trans Math Softw,1982,8:43-71
19Zhao D.Seismic structure and origin of hotspots and mantle plumes.Earth Planet Sci Lett,2001,192:251-265
20Humphreys E,Clayton R W.Adaptation of back projection tomography to seismic travel time problems.J Geophys Res,1988,93:1073-1085
21Liang C T,Song X D.A low velocity belt beneath northern and eastern Tibetan Plateau from Pn tomography.Geophys Res Lett,2006,33,doi:10.1029/2006GL027926
22Huang J L,Zhao D P.High-resolution mantle tomography of China and surrounding regions.J Geophys Res,2006,111,doi:10.1029/2005JB004066
23周华伟,Murphy M A,林清良.西藏及其周围地区地壳、地幔地震层析成像—印度板块大规模俯冲于西藏高原之下的证据.地学前缘,2002,9:285-292
24孙若昧,张中杰,滕吉文.青藏高原物质侧向流动的讨论—面波层析成像的证据.见:张中杰,高锐,吕庆田,等,编.中国大陆地球深部结构与动力学研究.北京:科学出版社,2004.872-880
25张雪梅,孙若昧,滕吉文.青藏高原及其邻区地壳、岩石圈和软流层厚度研究.科学通报,2007,52:332-338
26Li C,Van der Hilst R D,Meltzer A S,et al.Subduction of the Indian lithosphere beneath the Tibetan Plateau and Burma.Earth Planet Sci Lett,2008,274:157-168
27Ren Y,Shen Y.Finite frequency tomography in southeastern Tibet:Evidence for the causal relationship between mantle lithosphere delamination and the north-south trending rats.J Geophys Res,2008,113,doi:10.1029/2008JB005615
28Makovsky Y,Klemperer S L.Measuring the seismic properties of Tibetan bright spats:Evidence for free aqueous fluids in the Tibetanmiddle crust.J Geophys Res,1999,104:10795-10825
29Fu Y Y V,Li A B,Chen Y J.Crustal and upper mantle structure of southeast Tibet from Rayleigh wave tomography.J Geophys Res,2010115.doi:10.1029/2009JB007160
30Bai D H,Unsworth M J,Meju M A,et aL.Crustal deformation of the eastern Tibetan plateau revealed by magnetotelluric imaging.Nat Geosci,2010,3:358-362
31赵国泽,陈小斌,王立凤,等.青藏高原东边缘地壳“管流”层的电磁探测证据.科学通报,2008,53:345-350
32Chen Y,Badal J,Hu J F.Love and Rayleigh wave tomography of the Qinghai—Tibet Plateau and surrounding areas.Pure Appl Geophys,2010.167:1171-1203
33Kumar P,Yuan X H,Kind R,et aL.Imaging the colliding Indian and Asian lithospheric plates beneath Tibet.J Geophys Res,2006,111,doi:10.1029/2008JB005615
34韦伟,孙若昧,石耀霖.青藏高原东南缘地震层析成像及汶川地震成因探讨.中国科学:地球科学,2010,40:831-839
35李志伟,胥颐,黄润秋.龙门山地区的P波速度结构与汶川地震的深部构造特旺.中国科学:地球科学,2011,41:283-290
36Zhao D P.Global tomographic images of mantle plumes and subducting slabs:Insight into deep Earth dynamics.Phys Earth Planet Inter,2004.146:3-34
37Singh A,Kumar M R.Seismic signatures of detached lithospheric fragments in the mantle beneath eastern Himalaya and southern Tibet.Earth Planet Sci Lett,2009,288:279-290
38Steinberger B.Plumes in a convecting mantle:Models and observations for individual hotspots.J Geophys Res,2000,105:11127-11152
2吴中海,张永双,胡道功,等.西藏错那-拿日雍错地堑的第四纪正断层作用及其形成机制探讨.第四纪研究,2008,28:232-242
3Jimenez-Munt I,Platt J P.Influence of mantle dynamics on the topographic evolution of the Tibetan Plateau:Results from numerical modeling.Tectonics,2006,25,doi:10.1029/2006TC001963
4Zhao J M,Yuan X H,Liu H B,et a1.The boundary between the Indian and Asian tectonic plates below Tibet.Proc Natl Acad Sci USA,2010.107:11229-11233
5Tilmann F,Ni J,Team I I S.Seismic imaging of the downwelling Indian lithosphere beneath central Tibet.Science,2003,300:1424-1427
6Nabelek J,Hetenyi G,Vergne J,et a1.Underplating in the Himalaya—Tibet Collision Zone Revealed by the Hi-CLIMB Experiment.Science,2009,325:1371-1374
7苏伟,王椿镛,黄忠贤.青藏高原及邻区的Rayleigh面波的方位各向异性.中国科学D辑:地球科学,2008,38:674-682
8Priestley K,Debayle E,McKenzie D,et a1.Upper mantle structure of eastern Asia from multimode surface waveform tomography.J Geophys Res,2006,111,doi:10.1029/2005JB004082
9Zhou H W,Murphy M A.Tornographic evidence for wholesale underthrusting of India beneath the entire Tibetan plateau.J Asian Earth Sci,2005,25:445-457
10Rapine R,Tilmann F,West M,et al.Crustal structure of northern and southern Tibet from surface wave dispersion analysis.J Geophys Res,2003,108,doi:10.1029/2001JB000445
11Lebedev S,van der Hilst R D.Global upper-mantle tomography with the automated multimode inversion of surface and S-wave forms.Geophys J Int,2008,173:505-518
12Chen Y,Badal J,Zhang Z J.Radial anisotropy in the crust and upper mantle beneath the Qinghai—Tibet Plateau and surrounding regions.J Asian Earth Sci.2009.36:289-302
13Zhang Z J,Klemperer S.Crustal structure of the Tethyan Himalaya,southern Tibet:New constraints from old wide-angle seismic data.Geophys J Int,2010,181:1247-1260
14Zhang Z J,Klemperer S L.West-east variation in crustal thickness in northern Lhasa block,central Tibet,from deep seismic sounding data.J Geophys Res,2005,110,doi:10.1029/2004JB003139
15Kennett B L N,Engdahl E R.Traveltimes for global earthquake location and phase identification.Geophys J Int,1991,105:429-465
16江国明,赵大鹏,张贵宾.远震层析成像中的地壳校正研究及应用.地球物理学报,2009,52:1508-1514
17Zhao D P,Hasegawa A,Horiuchi S.Deep structure of Japan subduction zone as derived from local,regional,and teleseismic events.J Geophys Res,1994,99:22313-22329
18Paige C C,Saunders M A.LSQR:An Algorithm for Sparse Linear-Equations and Sparse Least-Squares.ACM Trans Math Softw,1982,8:43-71
19Zhao D.Seismic structure and origin of hotspots and mantle plumes.Earth Planet Sci Lett,2001,192:251-265
20Humphreys E,Clayton R W.Adaptation of back projection tomography to seismic travel time problems.J Geophys Res,1988,93:1073-1085
21Liang C T,Song X D.A low velocity belt beneath northern and eastern Tibetan Plateau from Pn tomography.Geophys Res Lett,2006,33,doi:10.1029/2006GL027926
22Huang J L,Zhao D P.High-resolution mantle tomography of China and surrounding regions.J Geophys Res,2006,111,doi:10.1029/2005JB004066
23周华伟,Murphy M A,林清良.西藏及其周围地区地壳、地幔地震层析成像—印度板块大规模俯冲于西藏高原之下的证据.地学前缘,2002,9:285-292
24孙若昧,张中杰,滕吉文.青藏高原物质侧向流动的讨论—面波层析成像的证据.见:张中杰,高锐,吕庆田,等,编.中国大陆地球深部结构与动力学研究.北京:科学出版社,2004.872-880
25张雪梅,孙若昧,滕吉文.青藏高原及其邻区地壳、岩石圈和软流层厚度研究.科学通报,2007,52:332-338
26Li C,Van der Hilst R D,Meltzer A S,et al.Subduction of the Indian lithosphere beneath the Tibetan Plateau and Burma.Earth Planet Sci Lett,2008,274:157-168
27Ren Y,Shen Y.Finite frequency tomography in southeastern Tibet:Evidence for the causal relationship between mantle lithosphere delamination and the north-south trending rats.J Geophys Res,2008,113,doi:10.1029/2008JB005615
28Makovsky Y,Klemperer S L.Measuring the seismic properties of Tibetan bright spats:Evidence for free aqueous fluids in the Tibetanmiddle crust.J Geophys Res,1999,104:10795-10825
29Fu Y Y V,Li A B,Chen Y J.Crustal and upper mantle structure of southeast Tibet from Rayleigh wave tomography.J Geophys Res,2010115.doi:10.1029/2009JB007160
30Bai D H,Unsworth M J,Meju M A,et aL.Crustal deformation of the eastern Tibetan plateau revealed by magnetotelluric imaging.Nat Geosci,2010,3:358-362
31赵国泽,陈小斌,王立凤,等.青藏高原东边缘地壳“管流”层的电磁探测证据.科学通报,2008,53:345-350
32Chen Y,Badal J,Hu J F.Love and Rayleigh wave tomography of the Qinghai—Tibet Plateau and surrounding areas.Pure Appl Geophys,2010.167:1171-1203
33Kumar P,Yuan X H,Kind R,et aL.Imaging the colliding Indian and Asian lithospheric plates beneath Tibet.J Geophys Res,2006,111,doi:10.1029/2008JB005615
34韦伟,孙若昧,石耀霖.青藏高原东南缘地震层析成像及汶川地震成因探讨.中国科学:地球科学,2010,40:831-839
35李志伟,胥颐,黄润秋.龙门山地区的P波速度结构与汶川地震的深部构造特旺.中国科学:地球科学,2011,41:283-290
36Zhao D P.Global tomographic images of mantle plumes and subducting slabs:Insight into deep Earth dynamics.Phys Earth Planet Inter,2004.146:3-34
37Singh A,Kumar M R.Seismic signatures of detached lithospheric fragments in the mantle beneath eastern Himalaya and southern Tibet.Earth Planet Sci Lett,2009,288:279-290
38Steinberger B.Plumes in a convecting mantle:Models and observations for individual hotspots.J Geophys Res,2000,105:11127-11152
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心