银川盆地岩石圈结构——长观测距宽角反射与折射剖面结果
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摘要
利用2014年完成的穿过银川盆地人工源宽角反射与折射剖面的3炮长观测距资料,采用基于地震波走时反演方法的Rayinvr算法得到了研究区地壳和上地幔的速度结构.结果表明:研究区地壳厚度为42—48km,莫霍面沿剖面展布形态呈现出东西两侧浅、中部较深的特征,莫霍面最深的区段位于贺兰山下方.P波速度沿剖面随着深度的增加呈正梯度增大,然而在深度约为90—103km的岩石圈地幔中,识别出两组较明显的反射界面,两组界面之间并未发现P波速度随深度而显著增加,表明研究区下方存在与地球平均模型中速度随深度增加而增大不相符的速度结构,推测银川盆地下方岩石圈与软流圈之间可能存在速度过渡带.
By using P-wave travel time data from three shots of the deep seismic sounding profiles passing through Yinchuan basin in 2014,based on travel time inversion method Rayinvr,we get the crustal and upper-mantle structure in the studied area.The results show that crustal thickness in the studied area varies from 42 km to 48 km,Moho depth is shallower in the east and west sides of the profile,and much deeper in the middle segment,the deepest Moho interface is beneath Helan mountain.P wave velocity increases with the increasing of depth in a positive gradient,but two distinct interfaces can be identified in the lithosphere mantle within the depths of 90--103 km.This layer does not exhibit the characteristic that the velocity increases obviously with the depth,suggesting the structure in the studied area present a characteristic that did not conform to the global average model,whose velocity increases according to the depth,therefore it is deduced that a velocity transition zone exists between lithosphere and asthenosphere beneath Yinchuan basin.
By using P-wave travel time data from three shots of the deep seismic sounding profiles passing through Yinchuan basin in 2014,based on travel time inversion method Rayinvr,we get the crustal and upper-mantle structure in the studied area.The results show that crustal thickness in the studied area varies from 42 km to 48 km,Moho depth is shallower in the east and west sides of the profile,and much deeper in the middle segment,the deepest Moho interface is beneath Helan mountain.P wave velocity increases with the increasing of depth in a positive gradient,but two distinct interfaces can be identified in the lithosphere mantle within the depths of 90--103 km.This layer does not exhibit the characteristic that the velocity increases obviously with the depth,suggesting the structure in the studied area present a characteristic that did not conform to the global average model,whose velocity increases according to the depth,therefore it is deduced that a velocity transition zone exists between lithosphere and asthenosphere beneath Yinchuan basin.
引文
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徐涛,徐果明,高尔根,朱良保,蒋先艺.2004.三维复杂介质的块状建模和试射射线追踪[J].地球物理学报,47(6):1118--1126.Xu T,Xu G M,Gao E G,Zhu L B,Jiang X Y.2004.Block modeling and shooting ray tracing in complex 3-D media[J].Chinese Journal of Geophysics,47(6):1118--1126(in Chinese).
杨卓欣,段永红,王夫运,赵金仁,潘素珍,李莉.2009.银川盆地深地震断层的三维透射成像[J].地球物理学报,52(8):2026--2034.Yang Z X,Duan Y H,Wang F Y,Zhao J R,Pan S Z,Li L.2009.Tomographic determination of the deep earthquake faults in Yinchuan basin by using three-dimensional seismic transmission technology[J].Chinese Journal of Geophysics,52(8):2026--2034(in Chinese).
俞贵平,徐涛,张明辉,白志明,刘有山,武澄泷,滕吉文.2017.三维复杂地壳结构非线性走时反演[J].地球物理学报,60(4):1398--1410.Yu G P,Xu T,Zhang M H,Bai Z M,Liu Y S,Wu C L,Teng J W.2017.Nonlinear travel-time inversion for 3-D complex crustal velocity structure[J].Chinese Journal of Geophysics,60(4):1398--1410(in Chinese).
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朱日祥,徐义刚,朱光,张宏福,夏群科,郑天愉.2012.华北克拉通破坏[J].中国科学:地球科学,42(8):1135--1159.Zhu R X,Xu Y G,Zhu G,Zhang H F,Xia Q K,Zheng T Y.2012.Destruction of the North China Craton[J].Science China Earth Sciences,55(10):1565--1587.
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Chen L.2009.Lithospheric structure variations between the eastern and central North China Craton from S-and P-receiver function migration[J].Phys Earth Planet Inter,173(3/4):216--227.
Chen L,Cheng C,Wei Z G.2009.Seismic evidence for significant lateral variations in lithospheric thickness beneath the central and western North China Craton[J].Earth Planet Sci Lett,286(1/2):171--183.
Chen L,Jiang M M,Yang J H,Wei Z G,Liu C Z,Ling Y.2014.Presence of an intralithospheric discontinuity in the central and western North China Craton:Implications for destruction of the craton[J].Geology,42(3):223--226.
Darby B J,Ritts B D.2002.Mesozoic contractional deformation in the middle of the Asian tectonic collage:The intraplate western Ordos fold-thrust belt,China[J].Earth Planet Sci Lett,205(1/2):13--24.
Fuchs K,Tittgemeyer M,Ryberg T,Wenzel F,Mooney W.2002.Global significance of a sub-Moho boundary layer(SMBL)deduced from high-resolution seismic observations[J].Int Geol Rev,44(8):671--685.
Hamza V M,Vieira F P.2012.Global distribution of the lithosphere-asthenosphere boundary:A new look[J].Solid Earth,3(2):199--212.
Jia S X,Wang F Y,Tian X F,Duan Y H,Zhang J S,Liu B F,Lin J Y.2014.Crustal structure and tectonic study of North China Craton from a long deep seismic sounding profile[J].Tectonophysics,627:48--56.
O′Reilly S Y,Griffin W L.2010.The continental lithosphere-asthenosphere boundary:Can we sample it?[J].Lithos,120(1/2):1--13.
Rawlinson N,Houseman G A,Collins C D N.2001.Inversion of seismic refraction and wide-angle reflection traveltimes for three-dimensional layered crustal structure[J].Geophys J Int,145(2):381--400.
Rychert C A,Shearer P M.2009.A global view of the lithosphere-asthenosphere boundary[J].Science,324(5926):495--498.
Thybo H,Perchuc′E.1997.The seismic 8°discontinuity and partial melting in continental mantle[J].Science,275(5306):1626--1629.
Tian X F,Zelt C A,Wang F Y,Jia S X,Liu Q X.2014.Crust structure of the North China Craton from a long-range seismic wide-angle-reflection/refraction data[J].Tectonophysics,634:237--245.
Xu T,Xu G M,Gao E G,Li Y C,Jiang X Y,Luo K Y.2006.Block modeling and segmentally iterative ray tracing in complex 3D media[J].Geophysics,71(3):T41--T51.
Xu T,Zhang Z J,Gao E G,Xu G M,Sun L.2010.Segmentally iterative ray tracing in complex 2Dand 3Dheterogeneous block models[J].Bull Seismol Soc Am,100(2):841--850.
Xu T,Li F,Wu Z,Wu C,Gao E,Zhou B,Zhang Z,Xu G.2014.A successive three-point perturbation method for fast ray tracing in complex 2Dand 3Dgeological models[J].Tectonophysics,627:72--81.
Yuan H Y,Romanowicz B.2010.Lithospheric layering in the North American craton[J].Nature,466(7310):1063--1068.
Zelt C A,Ellis R M.1988.Practical and efficient ray tracing in two-dimensional media for rapid traveltime and amplitude forward modelling[J].Canadian J Explor Geophys,24(1):16--31.
Zelt C A,Smith R B.1992.Seismic traveltime inversion for 2-D crustal velocity structure[J].Geophys J Int,108(1):16--34.
段永红,刘保金,赵金仁,刘保峰,张成科,潘素珍,林吉焱,郭文斌.2015.华北构造区岩石圈二维P波速度结构特征:来自盐城-包头深地震测深剖面的约束[J].中国科学:地球科学,45(8):1183--1197.Duan Y H,Liu B J,Zhao J R,Liu B F,Zhang C K,Pan S Z,Lin J Y,Guo W B.2015.2-D P-wave velocity structure of lithosphere in the North China tectonic zone:Constraints from the Yancheng-Baotou deep seismic profile[J].Science China Earth Sciences,58(9):1577--1591.
酆少英,刘保金,姬计法,何银娟,谭雅丽,李怡青.2015.呼和浩特-包头盆地岩石圈细结构的深地震反射探测[J].地球物理学报,58(4):1158--1168.Feng S Y,Liu B J,Ji J F,He Y J,Tan Y L,Li Y Q.2015.The survey on fine lithospheric structure beneath HohhotBaotou basin by deep seismic reflection profile[J].Chinese Journal of Geophysics,58(4):1158--1168(in Chinese).
黄兴富,施炜,李恒强,陈龙,岑敏.2013.银川盆地新生代构造演化:来自银川盆地主边界断裂运动学的约束[J].地学前缘,20(4):199--210.Huang X F,Shi W,Li H Q,Chen L,Cen M.2013.Cenozoic tectonic evolution of the Yinchuan basin:Constraints from the deformation of its boundary faults[J].Earth Science Frontiers,20(4):199--210(in Chinese).
嘉世旭,张先康.2008.青藏高原东北缘深地震测深震相研究与地壳细结构[J].地球物理学报,51(5):1431--1443.Jia S X,Zhang X K.2008.Study on the crust phases of deep seismic sounding experiments and fine crust structures in the northeast margin of Tibetan Plateau[J].Chinese Journal of Geophysics,51(5):1431--1443(in Chinese).
李飞,徐涛,武振波,张忠杰,滕吉文.2013.三维非均匀地质模型中的逐段迭代射线追踪[J].地球物理学报,56(10):3514--3522.Li F,Xu T,Wu Z B,Zhang Z J,Teng J W.2013.Segmentally iterative ray tracing in 3-D heterogeneous geological models[J].Chinese Journal of Geophysics,56(10):3514--3522(in Chinese).
刘保金,酆少英,姬计法,王帅军,张建狮,袁洪克,杨国俊.2017.贺兰山和银川盆地的岩石圈结构和断裂特征:深地震反射剖面结果[J].中国科学:地球科学,47(2):179--190.Liu B J,Feng S Y,Ji J F,Wang S J,Zhang J S,Yuan H K,Yang G J.2017.Lithospheric structure and faulting characteristics of the Helan Mountains and Yinchuan basin:Results of deep seismic reflection profiling[J].Science China Earth Sciences,60(3):589--601.
刘建辉,张培震,郑德文,万景林,王伟涛,杜鹏,雷启云.2010.贺兰山晚新生代隆升的剥露特征及其隆升模式[J].中国科学:地球科学,40(1):50--60.Liu J H,Zhang P Z,Zheng D W,Wan J L,Wang W T,Du P,Lei Q Y.2010.Pattern and timing of Late Cenozoic rapid exhumation and uplift of the Helan Mountain,China[J].Science China Earth Sciences,53(3):345--355.
刘志,王夫运,张先康,段永红,杨卓欣,林吉焱.2015.华北克拉通东部地壳与地幔盖层结构:长观测距深地震测深剖面结果[J].地球物理学报,58(4):1145--1157.Liu Z,Wang F Y,Zhang X K,Duan Y H,Yang Z X,Lin J Y.2015.Seismic structure of the lithosphere beneath eastern North China Craton:Results from long distance deep seismic sounding[J].Chinese Journal of Geophysics,58(4):1145--1157(in Chinese).
王帅军,王夫运,张建狮,嘉世旭,张成科,赵金仁,刘宝峰.2014.华北克拉通岩石圈二维P波速度结构特征:文登-阿拉善左旗深地震测深剖面结果[J].中国科学:地球科学,44(12):2697--2708.Wang S J,Wang F Y,Zhang J S,Jia S X,Zhang C K,Zhao J R,Liu B F.2014.The P-wave velocity structure of the lithosphere of the North China Craton:Results from the Wendeng-Alxa left banner deep seismic sounding profile[J].Science China Earth Sciences,57(9):2053--2063.
徐涛,徐果明,高尔根,朱良保,蒋先艺.2004.三维复杂介质的块状建模和试射射线追踪[J].地球物理学报,47(6):1118--1126.Xu T,Xu G M,Gao E G,Zhu L B,Jiang X Y.2004.Block modeling and shooting ray tracing in complex 3-D media[J].Chinese Journal of Geophysics,47(6):1118--1126(in Chinese).
杨卓欣,段永红,王夫运,赵金仁,潘素珍,李莉.2009.银川盆地深地震断层的三维透射成像[J].地球物理学报,52(8):2026--2034.Yang Z X,Duan Y H,Wang F Y,Zhao J R,Pan S Z,Li L.2009.Tomographic determination of the deep earthquake faults in Yinchuan basin by using three-dimensional seismic transmission technology[J].Chinese Journal of Geophysics,52(8):2026--2034(in Chinese).
俞贵平,徐涛,张明辉,白志明,刘有山,武澄泷,滕吉文.2017.三维复杂地壳结构非线性走时反演[J].地球物理学报,60(4):1398--1410.Yu G P,Xu T,Zhang M H,Bai Z M,Liu Y S,Wu C L,Teng J W.2017.Nonlinear travel-time inversion for 3-D complex crustal velocity structure[J].Chinese Journal of Geophysics,60(4):1398--1410(in Chinese).
张进,李锦轶,李彦峰,马宗晋.2007.阿拉善地块新生代构造作用:兼论阿尔金断裂新生代东向延伸问题[J].地质学报,81(11):1481--1497.Zhang J,Li J Y,Li Y F,Ma Z J.2007.The Cenozoic deformation of the Alxa block in central Asia:Question on the northeastern extension of the Altyn Tagh fault in Cenozoic time[J].Acta Geologica Sinica,81(11):1481--1497(in Chinese).
朱日祥,陈凌,吴福元,刘俊来.2011.华北克拉通破坏的时间、范围与机制[J].中国科学:地球科学,41(5):583--592.Zhu R X,Chen L,Wu F Y,Liu J L.2011.Timing,scale and mechanism of the destruction of the North China Craton[J].Science China Earth Sciences,54(6):789--797.
朱日祥,徐义刚,朱光,张宏福,夏群科,郑天愉.2012.华北克拉通破坏[J].中国科学:地球科学,42(8):1135--1159.Zhu R X,Xu Y G,Zhu G,Zhang H F,Xia Q K,Zheng T Y.2012.Destruction of the North China Craton[J].Science China Earth Sciences,55(10):1565--1587.
Barrell J.1914.The strength of the Earth’s crust[J].J Geol,22(6):537--555.
C′erven y′V.2001.Seismic Ray Theory[M].Cambridge:Cambridge University Press:99--228.
Chen L.2009.Lithospheric structure variations between the eastern and central North China Craton from S-and P-receiver function migration[J].Phys Earth Planet Inter,173(3/4):216--227.
Chen L,Cheng C,Wei Z G.2009.Seismic evidence for significant lateral variations in lithospheric thickness beneath the central and western North China Craton[J].Earth Planet Sci Lett,286(1/2):171--183.
Chen L,Jiang M M,Yang J H,Wei Z G,Liu C Z,Ling Y.2014.Presence of an intralithospheric discontinuity in the central and western North China Craton:Implications for destruction of the craton[J].Geology,42(3):223--226.
Darby B J,Ritts B D.2002.Mesozoic contractional deformation in the middle of the Asian tectonic collage:The intraplate western Ordos fold-thrust belt,China[J].Earth Planet Sci Lett,205(1/2):13--24.
Fuchs K,Tittgemeyer M,Ryberg T,Wenzel F,Mooney W.2002.Global significance of a sub-Moho boundary layer(SMBL)deduced from high-resolution seismic observations[J].Int Geol Rev,44(8):671--685.
Hamza V M,Vieira F P.2012.Global distribution of the lithosphere-asthenosphere boundary:A new look[J].Solid Earth,3(2):199--212.
Jia S X,Wang F Y,Tian X F,Duan Y H,Zhang J S,Liu B F,Lin J Y.2014.Crustal structure and tectonic study of North China Craton from a long deep seismic sounding profile[J].Tectonophysics,627:48--56.
O′Reilly S Y,Griffin W L.2010.The continental lithosphere-asthenosphere boundary:Can we sample it?[J].Lithos,120(1/2):1--13.
Rawlinson N,Houseman G A,Collins C D N.2001.Inversion of seismic refraction and wide-angle reflection traveltimes for three-dimensional layered crustal structure[J].Geophys J Int,145(2):381--400.
Rychert C A,Shearer P M.2009.A global view of the lithosphere-asthenosphere boundary[J].Science,324(5926):495--498.
Thybo H,Perchuc′E.1997.The seismic 8°discontinuity and partial melting in continental mantle[J].Science,275(5306):1626--1629.
Tian X F,Zelt C A,Wang F Y,Jia S X,Liu Q X.2014.Crust structure of the North China Craton from a long-range seismic wide-angle-reflection/refraction data[J].Tectonophysics,634:237--245.
Xu T,Xu G M,Gao E G,Li Y C,Jiang X Y,Luo K Y.2006.Block modeling and segmentally iterative ray tracing in complex 3D media[J].Geophysics,71(3):T41--T51.
Xu T,Zhang Z J,Gao E G,Xu G M,Sun L.2010.Segmentally iterative ray tracing in complex 2Dand 3Dheterogeneous block models[J].Bull Seismol Soc Am,100(2):841--850.
Xu T,Li F,Wu Z,Wu C,Gao E,Zhou B,Zhang Z,Xu G.2014.A successive three-point perturbation method for fast ray tracing in complex 2Dand 3Dgeological models[J].Tectonophysics,627:72--81.
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