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华北地区410km间断面和660km间断面结构—克拉通活化的地幔动力学状态探测

, PP. 678-685

Keywords: 410km间断面,660km间断面,接收函数成像,地幔动力学状态,华北克拉通

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Abstract:

?地幔过渡带间断面的形态能够提供地幔动力学状态的重要信息.本文利用密集流动台阵观测获得的地震波形记录,采用高分辨的地壳-上地幔速度结构成像结果作为接收函数共转换点叠加的速度模型,获得了华北克拉通地区地幔过渡带410km间断面和660km间断面深度的空间分布.结果揭示华北克拉通410km间断面和660km间断面结构的空间变化显著,存在多处间断面深度异常.地幔过渡带的结构特征以南北重力梯度带为界分为东西两部分;410km间断面变深(420~430km)的区域主要分布在华北克拉通东部,660km间断面变浅(642~655km)的区域出现在华北克拉通西北部;在华北克拉通东南部,660km间断面显著加深.本文分析认为,停滞在地幔过渡带的太平洋俯冲板块、厚度剧烈变化的克拉通岩石圈以及它们与周围地幔的相互作用,导致华北克拉通下存在活跃的地幔流动体系,造成过渡带间断面形态的高度不均匀.本文推测了两种可能的地幔过程:在克拉通根厚度显著变化的区域发生减压熔融,或者边界驱动的对流引起地幔物质沿着厚的克拉通根向上流动;或者是停滞在地幔过渡带的俯冲板块部分沉入下地幔,同时导致被排出的下地幔物质上升.

References

[1]  1 Anderson D L. Theory of the Earth. Boston: Blackwell Scientific Publication, 1989. 366-366
[2]  2 Birch F. Elasticity and constitution of the Earth’s interior. J Geophys Res, 1952, 57: 227-286??
[3]  3 Ringwood A E. Composition and Petrology of the Earth’s Mantle. New York: McGraw-Hill, 1975. 618
[4]  4 Katsura T, Ito E. The system Mg2SiO4-Fe2SiO4 at high pressures and temperatures: Precise determination of stabilities of olivine, modified spinel, and spinel. J Geophys Res, 1989, 94: 15663-15670??
[5]  5 Bina C R, Helffrich G R. Phase transition Clapeyron slopes and transition zone seismic discontinuity topography. J Geophys Res, 1994, 99: 15853-15860??
[6]  6 Stixrude L. Structure and sharpness of phase transitions and mantle discontinuities. J Geophys Res, 1997, 102: 14835-14852??
[7]  7 Revenaugh J, Jordan T H. Mantle layering from ScS reverberations: 2. The transition zone. J Geophys Res, 1991, 96(B12): 19763-19780
[8]  8 Gu Y J, Dziewonski A M. Global variability of transition zone thickness. J Geophys Res, 2002, 107, doi: 10.1029/ 2001JB000489
[9]  9 Ai Y S, Zheng T Y. The upper mantle discontinuity structure beneath eastern China. Geophys Res Lett, 2003, 30: 2089, doi: 10.1029/2003GL017678??
[10]  10 Ozacar A A, Gilbert H, Zandt G. Upper mantle discontinuity structure beneath East Anatolian Plateau (Turkey) from receiver functions. Earth Planet Sci Lett, 2008, 281: 426-434
[11]  11 Lawrence J F, Shearer P M. Imaging mantle transition zone thickness with SdS-SS finite-frequency sensitivity kernels. Geophys J Int, 2008, 174: 143-158??
[12]  12 Chen L, Ai Y S. Discontinuity structure of the mantle transition zone beneath the North China Craton from receiver function migration. J Geophys Res, 2009, 114: B06307, doi: 10.1029/2008JB006221
[13]  13 Li X Q, Kind R, Yuan X H. Seismic study of upper mantle and transition zone beneath hotspots. Phys Earth Planet Inter, 2003, 136: 79-92??
[14]  14 Schmerr N, Garnero E J. Upper mantle discontinuity topography from thermal and chemical heterogeneity. Science, 2007, 318: 623-626??
[15]  15 Bercovici D, Karato S I. Whole-mantle convection and the transition-zone water filter. Nature, 2003, 425: 39-44??
[16]  16 Meier U, Trampert J, Curtis A. Global variations of temperature and water content in the mantle transition zone from higher mode surface waves. Earth Planet Sci Lett, 2009, 282: 91-101??
[17]  17 Leahy G M. Local variability in the 410-km mantle discontinuity under a hotspot. Earth Planet Sci Lett, 2009, 288: 158-163??
[18]  18 朱日祥, 郑天愉. 华北克拉通破坏机制与古元古代板块构造体系. 科学通报, 2009, 54: 1950-1961
[19]  19 Huang J L, Zhao D P. High-resolution mantle tomography of China and surrounding regions. J Geophys Res, 2006, 111: B09305, doi: 10.1029/2005JB004066
[20]  20 Li C, Van der Hilst R D, Nafi Toksǒz M. Constraining P-wave velocity variations in the upper mantle beneath Southeast Asia. Phys Earth Planet Inter, 2006, 154: 180-195??
[21]  21 Zhao L, Allen R M, Zheng T Y, et al. Reactivation of an Archean Craton: Constraints from P- and S-wave tomography in North China. Geophys Res Lett, 2009, 36: L17306, doi: 10.1029/2009GL039781??
[22]  22 Tian Y, Zhao D P, Sun R M, et al. Seismic imaging of the crust and upper mantle beneath the North China Craton. Phys Earth Planet Inter, 2009, doi: 10.1016/j.pepi.2008.09.002
[23]  23 Huang Z X, Su W, Peng Y, et al. Rayleigh wave tomography of China and adjacent regions. J Geophys Res, 2003, 108: 2073, doi: 10.1029/ 2001JB001696??
[24]  24 Zhu L P. Crustal structure across the San Andreas Fault, Southern California from teleseismic converted waves. Earth Planet Sci Lett, 2000, 179: 183-190??
[25]  25 吴庆举, 曾融生. 用宽频带远震接收函数研究青藏高原的地壳结构. 地球物理学报, 1998, 41: 669-679
[26]  26 Zheng T Y, Chen L, Zhao L, et al. Crust-mantle structure difference across the gravity gradient zone in North China Craton, Seismic image of the thinned continental crust. Phys Earth Planet Inter, 2006, 159: 43-58, doi: 10.1016/ j.pepi.2006.05.004??
[27]  27 Zheng T Y, Chen L, Zhao L, et al. Crustal structure across the Yanshan belt at the northern margin of the North China Craton. Phys Earth Planet Inter, 2007, 161: 36-49, doi: 10.1016/ j.pepi.2007.01.004??
[28]  28 Zheng T Y, Zhao L, Xu W W, et al. Insight into modification of North China Craton from seismological study in the Shandong Province. Geophys Res Lett, 2008, 35: L22305, doi: 10.1029/ 2008GL035661??
[29]  29 Zheng T Y, Zhao L, Zhu R X. New evidence from seismic imaging for subduction during assembly of the North China Craton. Geology, 2009, 37: 395-398, doi: 10.1130/G25600A.1??
[30]  30 高山, 骆庭川, 张本仁, 等. 中国东部地壳的结构和组成. 中国科学D辑: 地球科学, 1999, 29: 204-213
[31]  31 Kei H, Fei Y, Ma Y, et al. The fate of subducted basaltic crust in the Earth’s lower mantle. Nature, 1999, 397: 53-56??
[32]  32 Arwen D, Redfern S A T, Chambers K, et al. The nature of the 660-kilometer discontinuity in Earth’s mantle from global seismic observations of PP precursors. Science, 2006, 311, doi: 10.1126/science.1120020
[33]  33 Kind S D, Ritsema J. African hot spot volcanism: Small-scale convection in the upper mantle beneath cratons. Science, 2000, 290: 1137-1140??
[34]  34 Niu Y L. Generation and evolution of basaltic magmas: Some basic concepts and a new view on the origin of Mesozoic-Cenozoic basaltic volcanism in eastern China. Geol J China Univ, 2005, 11: 9-46

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