Evidence of crustal ‘channel flow-in the eastern margin of Tibetan Plateau from MT measurements
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- 作者：GuoZe Zhao (1)
XiaoBin Chen (1)
LiFeng Wang (1)
JiJun Wang (1)
Ji Tang (1)
ZhanSheng Wan (1)
JiHong Zhang (2)
Yan Zhan (1)
QiBin Xiao (1) - 关键词：eastern margin of Tibetan Plateau ; magnetotelluric ; electric structure ; channel flow ; transitional zone
- 刊名：Chinese Science Bulletin
- 出版年：2008
- 出版时间：June 2008
- 年：2008
- 卷：53
- 期：12
- 页码：1887-1893
- 全文大小：712KB
- 参考文献：1. Royden L H, Clark B, King R W, et al. Surface deformation and lower crustal flow in eastern Tibet. Science, 1997, 276(5313): 788-90 CrossRef
2. Clark M K, Royden L H. Topographic ooze: Building the eastern margin of Tibet by lower crustal flow. Geology, 2000, 28(8): 703-06 CrossRef
3. Clark M, Royden L, Burchfiel B C, et al. Late Cenozoic uplift of southeastern Tibet: implication for lower crustal flow. Geophys Res Abs, 2003, 5: 12969
4. Unsworth M, Jones A J, Wei W, et al. Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data. Nature, 2005, 4383,doi:10:78-1
5. Grujic D. Channel flow and continental collision tectonics: an overview. Geol Soc London, 2006, 268: 25-7
6. Schoenbohm L M, Burchfiel B C, Chen L. Propagation of surface uplift, lower crustal flow, and cenozoic tectonics of the southeast margin of the Tibetan Plateau. Geology, 2006, 34(10): 813-16 CrossRef
7. Harris N. Channel flow and the Himalayan-Tibetan orogen: a critical review. Geol Soc London, 2007, 164: 511-23 CrossRef
8. Li S, Unsworth M, Booker J R, et al. Partial melt or aqueous fluid in the mid-crust of Southern Tibet? Constraints from INDEPTH magnetotelluric data. Geophys J Int, 2003, 153: 289-04 CrossRef
9. Cui Z Z, Lu D Y, Chen J P, et al. The deep structural and tectonic features of the crust in Panxi area. Acta Geophys Sin (in Chinese), 1987, 30(6): 566-80
10. Lu D Y, Cui Z Z, Chen J P, et al. Application of exploration seismic sounding in the study of the crustal structure of the Kangding-Dukou meridianal structural belt. Geol Rev (in Chinese), 1989, 35(1): 41-1
11. Cui Z Z, Chen J P, Wu L, et al. Deep Crustal Structure and Tectonics Along Profile Huashixia-Shaoyang (in Chinese). Beijing: Geological Publishing House, 1996. 128-80
12. Wang Y X, Han G H. Two-dimensional crustal velocity structure and regional tectonics in east margin of Tibet Plateau. In: Yuan X C, eds. Collection of Studies on GGT Artyn-Taiwan (in Chinese). Beijing: China University Geoscience Press, 1997, 56-0
13. Cao J M, Wang Y X. The crustal velocity structure of Maowen-Shaoyang section in profile Artyn-Taiwan. In: Yuan X C, ed. Collection of Studies on GGT Artyn-Taiwan (in Chinese). Beijing: China University Geoscience Press, 1997, 82-6
14. Kong X R, Wang Q S, Xiong S B. Comprehensive geophysical profile and lithosphere structures and geodynamics in the western Qinghai-Xizang (Tibetan) Plateau. Chin Sci Bull (in Chinese), 1999, 44(12): 1257-265
15. Yuan X C, Li T D, Xiao X C. 3D lithospheric structure of the Qinghai-Tibet Plateau and hydraulic pressure machine model of the plateau uplift. Geol China (in Chinese), 2006, 33(4): 711-29
16. Wang C Y, Wu J P, Lou H, et al. Study of crustal and upper mantle’s structure and mantle deformation field beneath the eastern Tibetan Plateau. Earth Sci Front (in Chinese), 2006, 13(5): 349-59
17. Wang C Y, Han W B, Wu J P, et al. Crustal structure beneath the eastern margin of the Tibetan Plateau and its tectonic implications. J G R, 2007, 112(B7): B07307, doi:10.1029/2005JB003873
18. Sun J, Jin G W, Bai D H, et al. Sounding of electrical structure of the crust and upper mantle along the eastern border of Qinghai-Tibet Plateau and its tectonic significance. Sci China Ser D-Earth Sci, 2003, 46(52): 243-53
19. Deng Q D, Chen S F, Zhao X L. Tectonics seismicity and dynamics of Longmenshan mountain and its adjacent regions. Seis Geol (in Chinese), 1994, 16(4): 389-03
20. Wen X Z. Character of rupture segmentation of the Xianshuihe, Anninghe-Zemuhe fault zone, western Sichuan. Seis Geol (in Chinese), 2000, 22(3): 239-49
21. Wen X Z, Yi G X. Re-Zoning of statistic units of seismicity in Sichuan-Yunnan region. J Seis Res (in Chinese). 2003, 26(Suppl.): 1-
22. Deng Q D, Ran Y K, Yang X P. Map of China Active Tectonics (in Chinese), Beijing: Seismological Press, 2007
23. Bureau of Geology and Mineral Resources of Sichuan Province. Regional Geology of Sichuan Province (in Chinese). Beijing: Geological Publishing House, 1991
24. Xu X W, Zhang P Z, Wen X Z, et al. Features of active tectonics and recurrence behaviors of strong earthquakes in the western Sichuan Province and its adjacent regions. Seis Geol (in Chinese), 2005, 27(3): 446-61
25. Li T M, Deng Z H, Lü Y P. Research on the crustal deformation data related to characteristics of strong earthquake (MS/610) distribution in the Area of Chuandian (Sichuan-Yunnan), China. Earthquake Res Chin (in Chinese), 2003, 19(2): 132-47
26. Xu X W, Cheng G L, Yu G H, et al. Tectonic and paleomagnetic evidence for the clockwise rotation of the Sichuan-Yunnan rhombic block. Seis Geol (in Chinese), 2003, 25(1): 61-0
27. 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 Geol Sin (in Chinese), 2005, 79(6): 748-56
28. Zhang P Z, Deng Q D, Zhang G M, et al. Active tectonic blocks and strong earthquakes in the continent of China. Sci China Ser D-Earth Sci, 2003, 46(S2): 13-4
29. Xu X W, Wen X Z, Zheng R Z, et al. Pattern of latest tectonic motion and its dynamics for active blocks in Sichuan-Yunnan region, China. Sci China Ser D-Earth Sci, 2003, 46(S2): 210-26
30. Xu X W, Wen X Z, Yu G H, et al. Average slip rate, rupturing segmentation and recurrence behavior on the Litang fault zone, western Sichuan Province, China Sci China Ser D-Earth Sci, 2005, 48(8): 1183-196 CrossRef
31. Shen Z, Lu J, Wang M, et al. Contemporary crustal deformation around the southeast borderland of the Tibetan Plateau. J G R, 2005, 110(B11409), doi:10.1029/2004JB003421
32. Wang X M, Zhang C D, Pei X Y. Structural activity and evolution since the late Quaternary on Anninghe faults. Earthquake Sichuan (in Chinese), 1998, (4): 1-2
33. Zhao G Z, Liu G D. Reference magnetotelluric method used in study of the crust and upper mantle structure, In: Institute of Geology, State Seismological Bureau, eds. Collected Works on Seismology (in Chinese). Tianjin: Science Technology Publishing House, 1986, 123-45
34. Jiang Z, Liu G D, Sun J, et al. Robust estimation and its application in the MT data processing. In: Liu G D, et al. eds. Investigation and Application of Electromagnetic Methods (in Chinese). Beijing: Seismological Press, 1993, 60-9
35. Zhang Q C, Yang S. An application and study of noise elimination for magnetotelluric sounding data. Geophys Prosp Petrol (in Chinese), 2002, 41(4): 493-99
36. Chen X B, Zhao G Z, Zhan Y. Visual window system for MT data processing and interpretation. Geophys Prosp Petrol (in Chinese), 2004, 39(suppl.): 11-6
37. Bahr K, Interpretation of the magnetotelluric impedance tensor: regional induction and local telluric distortion. J Geophys, 1988, 62: 119-27
38. Wang L F, Jin G W, Sun J, et al. The characteristics of rotational invariants of the earth electromagnetic response function. Compu Tech Geophy Expl (in Chinese), 2000, 22(4): 306-11
39. Wang L F, Jin G W, Sun J, et al. A simple decomposition method of distortion in magnetotelluric impedance tensor. NW Seis J (in Chinese), 2001, 21(2): 172-79
40. Zhao G Z, Tang J, Liu T S, et al. Preliminary interpretation of MT data along profile from Yanggao to Rongcheng: application of decomposition of MT impedance tensor. Seis Geol (in Chinese), 1996, 18(1): 66-4
41. Smith J T, Booker, J R. Rapid inversion of two-and three-dimensional magnetotelluric data. J G R, 1991, 96(b3): 3905-922 CrossRef
42. Chen X B. On the research of the influence of terrain to MT 2D forward computation. Geophys Prosp Petrol (in Chinese), 2000, 39(4): 112-20
43. Chen X B, Zhao G Z, Tang J, et al. An adaptive regularized inversion algorithm for magnetotelluric data. Chin J Geophys (in Chinese), 2005, 48(4): 937-46
44. Rodi W, Mackie R L. Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion. Geophys, 2001, 66(1): 174-87 CrossRef
45. Zhao G Z, Tang J, Zhan Y, et al. Relation between electricity structure of the crust and deformation of crustal blocks on the northeastern margin of Qinghai-Tibet plateau. Sci China Ser D-Earth Sci, 2005, 48(10): 1613-626 CrossRef
46. Jones A G, Electrical conductivity of the continental lower crust, in Continental Lower Crust. In: Fountain D, et al. eds. Continental Lower Crust. Elsevier, 1992. 81-43
47. Unsworth M, Wei W, Jones A G, et al. Crustal and upper mantle structure of northern Tibet imaged with magnetotelluric data. J G R, 2004,109(B02403), doi:10.1029/2002JB002305
48. Gaillard F, Scaillet B, Pichavant M. Evidence for present-day leucogranite pluton growth in Tibet. Geology, 2004, 32(9): 801-04, doi:10.1130/G20577 CrossRef
49. Tyburczy J A & Waff H S. Electrical conductivity of molten basalt and andesine to 25 kbar pressure: geophysical significance and implications for charge transport and melt structure. JGR, 1983, 88: 2413-430 CrossRef
50. Chen L, Booker J R, Jones A G, et al. Electrically conductive crust in southern Tibet from INDEPTH magnetotelluric surveying. Science, 1996, 274: 1694-696 CrossRef
51. Wei W, et al. Detection of widespread fluids in the Tibetan crust by magnetotelluric studies. Science, 2001, 292: 716-18 CrossRef
52. Nelson K D, et al. Partially molten middle crust beneath southern Tibet: synthesis of project INDEPTH results. Science, 1996, 274: 1684-687 CrossRef
53. Pham V N, et al. Partial melting zones in the crust in Southern Tibet from magnetotelluric results. Nature, 1986, 319: 310-14 CrossRef
54. Xu Z Q, Hou L W, Wang Z Y, et al. Orogenic Processes of the Songpan-Gatze Orogenic Belt of China (in Chinese). Beijing: Geological Publishing House, 1992
55. Li P. Xianshuihe-Xiaojiang Fault Zones (in Chinese). Beijing: Seismological Press, 1993
56. Teng J W. Rock Physics and Dynamics in Kangdian Tectonic Belt (in Chinese). Beijing: Science Press, 1994
57. Sun S C, Jia D, Hu Q W, et al. Fluid inclusion planes measurement and paleostress field analysis for Cenozoic Gonggashan granite. Geol J Chin Univ (in Chinese), 2007, 13(2): 344-52
58. Zhang Y Q, Chen W, Yang N. 40Ar/39Ar dating of shear deformati on of the Xianshuihe fault zone in west Sichuan and its tectonic significance. Sci China Ser D-Earth Sci, 2004, 47(4): 794-03
59. Liu S W, Zhang J J, Shu G M, et al. Mineral chemistry, P-T-t paths and exhumation processes of mafic granulites in Dinggye, Southern Tibet. Sci China Ser D-Earth Sci, 2005, 48(11): 1870-881 CrossRef
60. Roger F, Calassou S, Lancelot J, et al. Miocene emplacement and deformation of the Konga Shan granite (Xianshui He fault zone, west Sichuan, China): geodynamic implications. Earth Planet Sci Lett, 1995, 130: 201-16 CrossRef
61. Zhu J S, Cai X L, Cao J M, et al. The three-dimensional Structure of Lithosphere and Its Evolution in South China and East China Sea (in Chinese). Beijing: Geological Publishing House, 2005
62. Rosenberg C, Handy M R. Experimental deformation of partially melted granite revisited: implications for the continental crust. J Metamorph Geol, 2005, 23: 19-8 CrossRef
63. Rutter E, Neumann K. Experimental deformation of partially molten Westerly granite under fluid absent conditions with implications for the extraction of granite magmas. JGR, 1995, 100: 15697-5715 CrossRef
64. Van der Molen I & Paterson M S. Experimental deformation of partially molten granite. Contrib Mineral Petrol, 1979, 70: 299-18 CrossRef
65. Renner J, Evans B, Hirth G. On the rheologically critical melt fraction. Earth Planet Sci Lett, 2000, 181: 585-94 CrossRef
66. Hilley G E, Bü rgmann R, Zhang P Z, et al. Bayesian inference of plastosphere viscosities near the Kunlun Fault, northern Tibet. GRL, 2005, 32(L01302), doi:10.1029/2004GL021658
67. Medvedev S, Beaumont C. Growth of Continental Plateaus by Channel Injection: Constraints and Thermo-Mechanical Consistency. Geol Soc London, 2006, 268: 147-64 doi: 10.1144/GSL.SP.2006.268.01.06 CrossRef
68. Zhao G Z, Yukutake T, Hamano Y, et al. Investigation of magnetovariational data of the Juan de Fuca plate in the eastern Pacific Ocean. Chin J Geophys, 1990, 33(4): 469-77
69. Tnag J, Jin G W, Zhao G Z, et al. Induction arrow and its application in Tianchi volcano, Changbai mountains. Geol Rev (in Chinese), 1999, 45(S): 294-03
70. Zhan Y, Zhao G Z, Tang J, et al. Electric structure of the crust of Manas earthquake area in Xinjiang Uygur Autonmous Region. Seis Geol (in Chinese), 1999, 21(2): 159-67
71. Chen X B, Zhao G Z, Zhan Y, et al. Analysis of tipper visual vectors and its application. Earth Sci Front (in Chinese), 2004, 11(4): 626-36
72. Ma X Y. Lithospheric Dynamics Atlas of China (in Chinese). Beijing: China Cartographic Publishing House, 1989. 68
73. Zhang Z, Klemperer S L. West-east variation in crustal thickness in northern Lhasa block, central Tibet, from deep seismic sounding data. JGR, 2005, 110(B09403), doi:10.1029/2004JB003139
74. Zhu S B, Shi Y L. Genetic algorithm-finite element inversion of drag forces exerted by the lower crust on the upper crust in the Sichuan-Yunnan area. Chin J Geophys (in Chinese), 2004, 47(2): 232-39
75. Zhu A L, Xu X W, Zhou Y S, et al. Relocation of small earthquakes in western Sichuan, China and its implications for active tectonics. Chin J Geophys (in Chinese), 2005, 48(3): 629-36
76. Wang Z X, Xu Z Q, Yang T N, et al. Study of the deformation mechanism of the Xianshui river fault zone: a shallow level, high temperature ductile shear zone. Reg Geol China (in Chinese), 1996, (3): 245-51 - 作者单位：GuoZe Zhao (1)
XiaoBin Chen (1)
LiFeng Wang (1)
JiJun Wang (1)
Ji Tang (1)
ZhanSheng Wan (1)
JiHong Zhang (2)
Yan Zhan (1)
QiBin Xiao (1)
1. Institute of Geology, China Earthquake Administration, Beijing, 100029, China
2. Earthquake Administration of Shandong Province, Jinan, 250014, China - ISSN：1861-9541
文摘
Magnetotelluric (MT) survey has been carried out in the eastern margin of the Tibetan Plateau and its neighboring Shimian-Leshan area, Sichuan Province. Analysis of this MT data reveals that the electric structure of the Tibetan Plateau differ much from that of the Sichuan block. In general, the electric resistivity of crust beneath the Sichuan block in the east is larger than that of the eastern margin of the Tibetan Plateau in the west. The crust of the plateau is divided into upper, middle, and lower layers. The middle crust is a low resistivity layer with minimum down to 3-0 Ωm about 10-5 km thick. It presumably contains partial melt and/or salt-bearing fluids with low viscosity, prone to deform and flow, producing a “channel flow-under the southeastward squeeze of the eastern Tibetan Plateau. This low-resistivity layer makes the upper crust decoupled mechanically from the lower crust. In the brittle upper crust, faults are dominated by left-lateral strike-slip and thrust motions, leading to surface rising and shallow earthquakes. The low-resistivity layer also cut the Xianshuihe-Anninghe fault zone into two sections vertically. In this region, the thicknesses of upper, middle, and lower crust vary laterally, producing a transitional zone in the eastern margin of the Tibetan Plateau characterized by thicker crust and higher elevation in the west and thinner crust and lower elevation in the east.