用Rayleigh面波方位各向异性研究中国大陆岩石圈形变特征
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
中国大陆地质构造历史非常复杂,岩石圈长期积累的形变较大,而利用地震面波传播的各向异性是研究岩石圈形变特征的强有力手段.本文利用双台窄带通滤波-互相关方法与基于图像分析的相速度频散曲线提取技术,提取Rayleigh面波相速度频散资料,进而反演中国大陆及邻区20~120 s周期Rayleigh面波相速度方位各向异性空间分布图像.检测板测试结果显示:中国大陆大部分区域的方位各向异性横向分辨率在5°左右.各向异性研究结果表明:中国大陆地壳上地幔方位各向异性特征存在显著的空间差异,反映出形变特征的空间差异;104°E以东地区地壳上地幔各向异性弱于西部地区,表明其构造变形总体弱于西部地区.青藏地块及其东缘地区地壳与上地幔顶部变形最为强烈.但东部的局部地区如华南地块与珠江口地区、鄂尔多斯盆地西南缘以及秦岭-大别造山带,较强的各向异性显示这些区域在不同时期也经历了强变形.青藏地块内中短周期快波方向自西向东顺时针旋转变化可能指示板块碰撞与挤压过程中软弱物质的流变方向.青藏地块西部中下地壳和上地幔形变模式相似,可能处于壳幔耦合状态;而中东部及东缘地区地壳上地幔形变模式存在明显差异,壳幔似乎不具备垂直连贯的形变特征.位于青藏地块北部的塔里木盆地、柴达木盆地以及祁连褶皱带同样经历了强变形.包括四川盆地在内的上扬子地块快波方向的变化显示中地壳与下地壳上地幔形变模式不同,而形变特征一致的下地壳与上地幔应为强耦合.大约以103°E为界,龙门山断裂带可分为南西段和北东段,南西段处于低速区,而北东段位于高速区,且方位各向异性强度明显大于南西段;2008年5月12日汶川M_S8.0级地震沿断裂带的单侧破裂模式除与北东段的高应力积累有关外,还可能与北东段地下介质物性存在密切关系,高速坚硬岩体的发育有利于应变能的积累与集中释放.
The tectonic history of continental China is complicated and the associated Hthospheric deformation is large, while the use of the anisotropic propagation of surface waves is an important way to investigate the history of Hthospheric deformation pattern.We measured inter-station Rayleigh-wave phase velocity dispersion from cross-correlation of narrow band-pass filtered surface wave records and an image analysis technique.The dispersion data were then used to invert the distribution of azimuthal anisotropy at periods 20~120 s of continental China and its adjacent regions.Checkerboard tests show that the lateral resolution of phase velocity azimuthal anisotropy is about 5° in most area of continental China.Our results show that the pattern of azimuthal anisotropy in the study area displays clear spatial variations.The tectonic deformation of the crust and upper-mantle east of 104°E is generally weaker than that of the west as inferred from the relative magnitude of azimuthal anisotropy, and strong tectonic deformation had occurred in the crust and upper-mantle beneath Qinghai-Tibet plateau and its eastern margin.In eastern China relatively large amplitude of azimuthal anisotropy is observed in South China block and Pearl River Mouth basin, southwestern margin of Ordos basin and Qinling-Dabie orogenic belt, indicating strong tectonic deformation occurred there in the geological history.Fast propagation direction shows rotational pattern from the west to the east within the Qinghai-Tibet block at short and intermediate periods consistent with the clockwise extrusion (or escaping) of the crustal material in the block after the Eurasian and Indian collision.The deformation pattern in the mid-lower crust of western Qinghai-Tibet block is similar to that of the upper mantle, inferring possible vertically coherent deformation across the Moho interface.However, the central and eastern Qinghai-Tibet block and its eastern margin show different deformation patterns in the crust and upper mantle, which suggests that there is no apparent vertically coherent deformation between the crust and upper mantle.Strong tectonic deformation had occurred within Tarim and Qaidam basins as well as Qilian fold belt north of Qinghai-Tibet block.The fast propagation direction at the middle crustal depth is clearly different from those both in the lower crust and upper mantle underlying the upper Yangtze block including Sichuan basin.This suggests different tectonic deformation processes between the middle crust and lower crust beneath this block, while the lower crust and upper mantle appears to be coupled as inferred from the similar fast propagation direction at periods above 30 s.The Longmen Shan tectonic zone can be divided into southwestern and northeastern segments at about 103° E.The southwestern segment has relatively lower phase velocity while the northeastern area has higher phase velocity and stronger anisotropy.This suggests that the NE striking unilateral rupture propagation of the Wenchuan M_S8.0 earthquake on May 12 2008, may be related not only to the cumulated high stress of the northeastern section but also to the underlying medium property along the segment with high phase velocity suitable for strain energy accumulation and concentrated release.
引文
[1] Crampin S, Booth D C. Shear wave polarization near the North Anatolian fault, Ⅱ. Interpretation in terms of crack induced anisotropy. Geophys. J. R. astr. Soc., 1985, 83: 75~92
    [2] 张中杰.地震各向异性进展.地球物理学进展,2002,17(2) :281~293Zhang Z J. A review of the seismic anisotropy and its applications. Progress in Geophysics (in Chinese), 2002, 17 (2) : 281~293
    [3] 常利军,王椿镛,丁志峰等.青藏高原东北缘上地幔各向异性研究.地球物理学报,2008,51(2) :431~438Chang L J, Wang C Y, Ding Z F, et al. Seismic anisotropy of upper mantle in the northeastern margin of the Tibetan Plateau. Chinese J. Geophys. (in Chinese), 2008, 51 (2) : 431~438
    [4] 周兵.用地震面波研究上地幔各向异性.地震研究,1991,14(4) :401~408Zhou B. Anisotropy of the upper mantle from the inversion of surface wave data. Journal of Seismological Research (in Chinese), 1991, 14(4) : 401~408
    [5] Plomerová J, Kouba D, Babuka V. Mapping the lithosphere-asthenosphere boundary through changes in surface-wave anisotropy. Tectonophysics, 2002, 358: 175~185
    [6] Silver P G, Chan W W. Implication for continental structure and evolution from seismic anisotropy. Nature, 1988, 335: 34~39
    [7] Silver P G, Chan W W. Shear-wave splitting and subcontinental mantle deformation. J. Geophys. Res., 1991, 96: 16429~16454
    [8] 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:地球科学,2007,37(4) :495~503Wang C Y, Chang L J, Lü Z Y, et al. Seismic anisotropy of upper mantle in eastern Tibetan Plateau and related crustmantle coupling pattern. Sci. China Ser. D-Earth Sci. ,2007, 50(4) : 1150~1160
    [9] Montagner J p, Tanimoto T. Global upper mantle tomography of seismic velocities and anisotropics. J. Geophys. Res., 1991, 96: 20337~20351
    [10] Montagner J P, Tanimoto T. Global anisotropy in the upper mantle inferred from the regionalization of phase velocities. J. Geophys. Res. , 1990, 95:4797~4819
    [11] Debayle E, Kennett B, Priestiey K. Global azimuthal seismic anisotropy and the unique plate-motion deformation of Australia. Nature, 2005, 433(3) : 509~512
    [12] Vinnik L P, Makeyeva L I, Milev A, et al. Global patterns of azimuthal anisotropy and deformations in the continental mantle. Geophys. J. Int. , 1992, 111: 433~447
    [13] 郑斯华,高原.中国大陆岩石层的方位各向异性.地震学 报,1994,16(2) :131~140Zheng S H, Gao Y. Azimuthal anisotropy in lithosphere on the Chinese mainland from observations of SKS at CDSN. Acta Seismologica Sinica, 1994, 7(2) : 177~186
    [14] 高原,吴晶.利用剪切波各向异性推断地壳主压应力场:以首都圈地区为例.科学通报,2008,53(23) :2933~2939Gao Y, Wu J. Compressive stress field in the crust deduced from shear-wave anisotropy: an example in capital area of China. Chinese Science Bulletin, 2008, 53 (18) : 2840 ~2848. doi: 10. 1007/s11434-008-0310 9
    [15] Huang Z, Peng Y, Luo Y, et al. Azimuthal anisotropy of Rayleigh waves in East Asia. Geophys. Res. Lett., 2004, 31: L15617, doi:10. 1029/2004GL020399
    [16] 彭艳菊,黄忠贤,苏伟等.中国大陆及邻区海域地壳上地幔各向异性研究.地球物理学报,2007,50(3) :751~759Peng Y J, Huang Z X, Su W, et al. Anisotropy in crust and upper mantle beneath China continent and its adjacent seas.Chinese J. Geophys. (in Chinese), 2007, 50(3) :751~759
    [17] 常利军,王椿镛,丁志峰.四川及邻区上地幔各向异性研究.中国科学D辑:地球科学,2008,38(12) :1589~1599Chang L J, Wang C Y, Ding Z F. Seismic anisotropy of upper mantle in Sichuan and adjacent regions. Sci. China Ser. D-Earth Sci. , 2008, 51(12) : 1683~1693
    [18] Sol S, Meltzer A, Burgmann R, et al. Geodynamics of the southeastern Tibetan Plateau from seismic anisotropy and geodesy. Geology, 2007, 35(6) : 563~566
    [19] 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(6) :674~682Su W, Wang C Y, Huang Z X. Azimuthal anisotropy of Rayleigh waves beneath the Tibetan Plateau and adjacent areas. Sci. ChinaSer. D-EarthSci., 2008, 51(12) : 1717~1725
    [20] Yao H, van der Hilst R D, Montagner J P. Heterogeneity and anisotropic of the lithosphere of SE Tibet from ambient noise and surface wave array tomography. Submitted to J. Geophys. Res. , 2010
    [21] Fuchs K. Recently formed elastic anisotropy and petrological models for the continental subcrustal lithosphere in southern Germany. Phys. Earth Planet. Inter., 1983, 31: 93~118
    [22] Simons F J, van der Hilst R D, Montagner J P, et al. Multimode Rayleigh wave inversion for heterogeneity and azimuthal anisotropy of the Australian upper mantle. Geophys. J. Int. , 2002, 151:738~754
    [23] Montagner J P. Regional three-dimensional structures using long period surface waves. Ann. Geophys., 1986, 4: 283~294
    [24] Smith M L, Dahlen F A. The azimuthal dependence of Love and Rayleigh wave propagation in a slightly anisotropic medium. J. Geophy. Res. , 1973, 78:3321~3333
    [25] Yang Y J, Forsyth D W. Rayleigh wave phase velocities, small-scale convection, and azimuthal anisotropy beneath southern California. J. Geophys. Res. , 2006, 111: B07306, doi: 10. 1029/2005JB004180
    [26] Deschamps F, Lebedev S, Meier T, et al. Azimuthal anisotropy of Rayleigh-wave phase velocity in the east central United States. Geophys. J. Int. , 2008, 173:827~843
    [27] Maggi A, Debayle E, Priestley K, et al. Azimuthal anisotropy of the Pacific region. Earth Planet. Sci. Lett. , 2006, 250: 53~71, doi:10. 1016/j. epsl. 2006. 07. 010
    [28] 刘希强,周蕙兰,李红等.中国大陆及邻区上地幔各向异性研究.地震学报,2001,23(4) :337~348Liu X Q, Zhou H L, Li H, et al. Anisotropy of the upper mantle in Chinese mainland and its vicinity. Acta Seismologica Sinica, 2001, 14(4) : 359~370
    [29] 高原,滕吉文.中国大陆地壳与上地幔各向异性研究.地球物理学进展,2005,20(1) :180~185Gao Y, Teng J W. Studies on seismic anisotropy in the crust and mantle on Chinese mainland. Progress in Geophysics (in Chinese), 2005, 20(1) : 180~185
    [30] 姜枚,许志琴,Hirn A等.青藏高原及其部分邻区地震各向异性和上地幔特征.地球学报,2001,22(2) :111~116Jiang M, Xu Z Q, Hirn A, et al. Teleseismic anisotropy and corresponding features of the upper mantle in Tibet Plateau and its neighboring areas. Acta Geoscientia Sinica (in Chinese), 2001, 22(2) : 111~116
    [31] 石玉涛,高 原,吴 晶等.云南地区地壳介质各向异性--快剪切波偏振特性.地震学报,2006,28(6) :574~585Shi Y T, Gao Y, Wu J, et al. Seismicity anisotropy of the crust in Yunnan, China: polarization of fast shear-waves. Acta Seismologica Sinica, 2006, 19(6) : 620~632
    [32] 吴晶,高原,蔡晋安等.华夏地块东南部地壳地震各向异性特征初步研究.地球物理学报,2007,50(6) :1748~1756Wu J, Gao Y, Cai J A, et al. Preliminary study on seismic anisotropy in the curst in southeast of Cathaysia Block.Chinese J. Geophys. (in Chinese), 2007, 50(6) : 1748~1756
    [33] 胥颐,李志伟,郝天珧等.南海东北部及其邻近地区的Pn波速度结构与各向异性.地球物理学报,2007,50(5) :1473~1479Xu Y, Li Z W, Hao T Y, et al. Pn wave velocity and anisotropy in the northeastern South China Sea and adjacent region. Chinese J. Geophys. (in Chinese), 2007, 50 (5) :1473~1479
    [34] 胥颐,李志伟,刘劲松等.黄海及其邻近地区的Pn波速度结构与各向异性.地球物理学报,2008,51(5) :1444~1450Xu Y, Li Z W, Liu J S, et al. Pn wave velocity and anisotropy in the Yellow Sea and adjacent region. Chinese J. Geophys. (in Chinese), 2008, 51(5) : 1444~1450
    [35] 丁志峰,曾融生.青藏高原上地幔横波各向异性的探测研究.地球物理学报,1996,39(2) :211~220Ding Z F, Zeng R S. Observation and study of shear wave anisotropy in Tibetan Plateau. Chinese J. Geophys. (in Chinese), 1996, 39(2) : 211~220
    [36] Tanimoto T, Anderson D L. Lateral heterogeneity and azimuthal anisotropy of the upper mantle: Love and Rayleigh waves 100~250s. J. Geophys. Res., 1985, 90: 1842~1858
    [37] McNamara D, Owens T, Silver P G, et al. Shear wave anisotropy beneath the Tibetan Plateau. J. Geophys. Res. , 1994, 99:13655~13665
    [38] Hirn A, Jiang M, Sapin M, ctal. Seismic anisotropy as an indicator of mantle flow beneath Himalayas and Tibet. Nature, 1995, 75: 571~57
    [39] Lave T, Avouac J P, Lacassin R, et al. Seismic anisotropy beneath Tibet: evidence for eastward extrusion of the Tibetan lithosphere? Earth Planet. Sci.Lett., 1996, 140: 83~96
    [40] Becker T W, Kellogg J B, Ekstr(o|¨)m G, etal. Comparison of azimuthal seismic anisotropy from surfacc waves and finite strain from global mantle-circulation models. Geophys. J. Int. , 2003, 155:696~714
    [41] Leven J H, Jackson I, Ringwood A E. Upper mantle seismic anisotropy and lithospheric decoupling. Nature, 1981, 289: 234~239
    [42] Savage M K. Seismic anisotropy and mantle deformation: what have we learned from shear wave splitting? Rev. Geophys. , 1999, 37:65~106
    [43] 石耀霖,朱守彪.利用GPS观测资料划分现今地壳活动块体的方法.大地测量与地球动力学,2004,24(2) :1~5Shi Y L, Zhu S B. Method for division of present active crustal blocks by GPS survey data. Journal of Geodesy and Geodynamics (in Chinese), 2004, 24(2) : 1~5
    [44] 姚华建,徐果明,肖 翔等.基于图像分析的双台面波相速度频散曲线快速提取方法.地震地磁观测与研究,2004,25(1) :1~8Yao H J, Xu G M, Xiao X, et al. A quick tracing method based on image analysis technique for the determination of dual stations phase velocities dispersion curve of surface wave. Seismol. Geomagn. Observ. Res. (in Chinese), 2004, 25(1) : 1~8
    [45] Yao H, Xu G, Zhu L, et al. Mantle structure from interstation Rayleigh wave dispersion and its tectonic implication in western China and neighboring regions. Phys. Earth Planet. Inter. , 2005, 148:39~54
    [46] Tarantola A, Valette B. Generalized nonlinear inverse problems solved using the least square criterion. Rev. Geophys. Space Phys. , 1982, 20(2) : 219~232
    [47] Tarantola A, Nercessian A. Three-dimensional inversion with blocks. Geophys. J. R. astr. Soc., 1984, 76: 299~306
    [48] 易桂喜,姚华建,朱介寿等.中国大陆及邻区Rayleigh面波相速度分布特征.地球物理学报,2008,51(2) :402~411 Yi G X, Yao H J, Zhu J S, et al. Rayleigh-wave phase velocity distribution in China continent and its adjacent regions. Chinese J. Geophys. (in Chinese), 2008, 51 (2) : 402~411
    [49] 傅容珊,黄建华,徐耀光等.印度与欧亚板块碰撞的数值模拟和现代中国大陆形变.地震学报,2000,22(1) :1~7 Fu R S, Huang J H, Xu Y G, et al. Numerical simulation of the collision between Indian and Eurasian plates and the deformations of the present Chinese continent. Acta Seismologica Sinica, 2000, 13(1) : 1~7
    [50] 杨晓松,马瑾.大陆岩石圈解耦及块体运动讨论--以青藏高原-川滇地区为例.地学前沿,2003,10(特刊):240247 Yang X S, Ma J. Continental lithosphere decoupling: implication for block movement. Earth Science Frontiers (in Chinese), 2003, 10(S1) : 240~247
    [51] Rapine R, Tilmann F, West M, et al. Crustal structure of northern and southern Tibet from surface wave dispersion analysis. J. Geophys. Res. , 2003, 108(B2) : 2120, doi: 10. 1029/2001JB000445
    [52] Nelson K D. Partially molten middle crust beneath southern Tibet: synthesis of project INDEPTH results. Science, 1996, 274:1684~1688
    [53] McNamara D E, Walter W R, Owens T J, et al. Upper mantle velocity structure beneath the Tibetan Plateau from Pn travel time tomography. J. Geophys. Res. , 1997, 102: 493~505
    [54] 黄金莉,宋晓东,汪素云.川滇地区上地幔顶部Pn速度细结构.中国科学(D辑),2003,33(增刊):144~150 Huang J L, Song X D, Wang S Y. Fine structure of Pn velocity beneath Sichuan-Yunnan region. Sci. China Ser. D-Earth Sci. , 2003, 46(Suppl. ) : 201~209
    [55] Chen Z, Burchfiel B C, Liu Y, et al. Global positioning system measurements from eastern Tibet and their implications for India/Eurasia intercontinental deformation. J. Geophys. Res., 2000, 105(B7) : 16215~16227
    [56] Wang Q, Zhang P Z, Niu Z J, et al. Present-day crustal movement and tectonic deformation in China continent. Sci. China Ser. D-Earth Sci. , 2002, 45(10) : 865~874
    [57] 王伟,王琪.GPS观测约束下的中国大陆活动地块运动学模型.大地测量与地球动力学,2008,28(4) :75~88 Wang W, Wang Q. Kinematical model of crust blocks of China continent revealed by GPS measurements. Journal of Geodesy and Geodynamics (in Chinese), 2008, 28(4) : 75~88
    [58] Burchfiel B C, Wang E C. Northwest trending, Middle Cenozoic, left-lateral faults in southern Yunnan, China, and their tectonic significance. J. Structural Geology, 2003, 25 (5) : 781~792
    [59] 朱介寿.欧亚大陆及边缘海岩石圈的结构特性.地学前沿,2007,14(3) :1~20 Zhu J S. The structural characteristics of lithosphere in the continent of Eurasia and its marginal seas. Earth Science Frontiers (in Chinese), 2007, 14(3) : 1~20
    [60] Tapponnier P, Xu Z Q, Roger F, et al. Oblique stepwise rise and growth of the Tibet plateau. Science, 2001, 294: 1671~ 1677
    [61] Royden L H, Burchfiel B C, van der Hilst R D. The geological evolution of the Tibetan plateau. Science, 2008, 321 : 1054~1058
    [62] Royden L H, Burchfiel B C, King R W, et al. Surface deformation and lower crustal flow in eastern Tibet. Science, 1997, 276:788~790
    [63] Flesch M L, 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 Planet. Sci. Lett. , 2005, 238:248~268
    [64] Wang C Y, Flesch L M, Silver P G, et al. Evidence for mechanically coupled lithosphere in central Asia and resulting implication. Geology, 2008, 36: 363366, doi: 10. 1130/ G24450A. 1
    [65] Lev E, Long M D, van der Hilst R D. Seismic anisotropy in eastern Tibet from shear wave splitting reveals changes in lithospheric deformation. Earth Planet. Sci. Lett., 2006, 251:293304
    [66] 石玉涛,高原,赵翠萍等.汶川地震余震序列的地震各向异性.地球物理学报,2009,52(2) :398~407 Shi Y T, Gao Y, Zhao C P, et al. A study of seismic anisotropy of Wenchuan earthquake sequence. Chinese J. Geophys. (in Chinese), 2009, 52(2) : 398~407
    [67] 郭飚,刘启元,陈九辉等.川西龙门山及邻区地壳上地幔远震P波层析成像.地球物理学报,2009,52(2) :346~355 Guo B, liu Q Y, Chen J H, et al. Teleseismic P-wave tomography of the crust and upper mantle in Longmenshan area, west Sichuan. Chinese J. Geophys. (in Chinese), 2009, 52(2) : 346~355
    [68] 易桂喜,闻学泽,王思维等.由地震活动参数分析龙门山-岷山断裂带的现今活动习性与强震危险性.中国地震,2006,22(2) :117~125 Yi G X, Wen X Z , Wang S W, et al. Study on fault sliding behaviors and strong-earthquake risk of the Longmenshan-Minshan fault zones from current seismicity parameters.Earthquake Research in China (in Chinese), 2006, 22 (2) :117~125

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