Compressive tectonics around Tibetan plateau edges

Abstract

Various earthquake fault types, mechanism solutions, stress field, and other geophysical data were analyzed for study on the crust movement in the Tibetan plateau and its tectonic implications. The results show that numbers of thrust fault and strike-slip fault type earthquakes with strong compressive stress near NNE-SSW direction occurred in the edges around the plateau except the eastern boundary. Some normal faulting type earthquakes concentrate in the Central Tibetan plateau. The strikes of fault planes of thrust and strike-slip faulting earthquakes are almost in the E-W direction based on the analyses of the Wulff stereonet diagrams of fault plane solutions. This implies that the dislocation slip vectors of the thrust and strike-slip faulting type events have quite great components in the N-S direction. The compression motion mainly probably plays the tectonic active regime around the plateau edges. The compressive stress in N-S or NE-SW directions predominates earthquake occurrence in the thrust and strike-slip faulting event region around the plateau. The compressive motion around the Tibetan plateau edge is attributable to the northward motion of the Indian subcontinent plate. The northward motion of the Tibetan plateau shortened in the N-S direction encounters probably strong obstructions at the western and northern margins.

Keywords

thrust and strike-slip faulting earthquake / compressive stress / Tibetan plateau edge / P-axes / northward motion

References

[1] Avouac J., Tapponnier P.. Kinematic Model of Active Deformation in Central Asia. Geophys. Res. Lett., 1993, 20(10): 895-898.

[2] Bendick R., Bilham R., Freymueller J., . Geodetic Evidence for a Low Slip Rate in the Altyn Tagh Fault System. Nature, 2000, 404(6773): 69-72.

[3] Blisniuk P. M., Hacker B. R., Glodny J., . Normal Faulting in Central Tibet since at Least 13.5 Myr Ago. Nature, 2001, 412(6847): 628-632.

[4] Brown E. T., Bendick R., Bourles L. D., . Slip Rates of the Karakorum Fault, Ladakh, India, Determined Using Cosmic Ray Exposure Dating of Debris Flows and Moraines. J. Geophys. Res., 2002, 107(B9): 2192

[5] Chen Z., Burchfiel B. C., Liu Y., . Global Positioning System Measurements from Eastern Tibet and Their Implications for India/Eurasia Intercontinental Deformation. J. Geophys. Res., 2000, 105(B7): 16215-16227.

[6] Fu R. S., Xu Y. M., Huang J. H., . Numerical Simulation of the Compression Uplift of the Qinghai-Xizang Plateau. Chinese J. Geophys., 2000, 43(3): 346-355.

[7] Harrison T. M., Copeland P., Kidd W. S. F., . Raising Tibet. Science, 1992, 255(5052): 1663-1670.

[8] Klemperer, S. L., 2006. Crustal Flow in Tibet: Geophysical Evidence for the Physical State of Tibetan Lithosphere, and Inferred Patterns of Active Flow. In: Law, R. D., Searle, M. P., Godin, L., eds., Channel Flow, Ductile Extrusion and Exhumation in Continental Collision Zones. Geol. Soc. Special Publications, 268: 39–70

[9] Molnar P., England P., Martinod J.. Mantle Dynamics, Uplift of the Tibetan Plateau, and the Indian Monsoon. Reviews of Geophysics, 1993, 31(4): 357-396.

[10] Molnar P., Tapponnier P.. Cenozoic Tectonics of Asia: Effects of a Continental Collision. Science, 1975, 189(4201): 419-426.

[11] Qin C. Y., Papazachos C., Papadimitriou E.. Velocity Field for Crustal Deformation in China Derived from Seismic Moment Tensor Summation of Earthquakes. Tectonophysics, 2002, 359(1–2): 29-46.

[12] Ralf H., Samuel N., Tao M. X., . Low Slip Rates and Long-Term Preservation of Geomorphic Features in Central Asia. Nature, 2002, 417(6887): 428-432.

[13] Shen Z. K., Wang M., Li Y. X., . Crustal Deformation along the Altyn Tagh Fault System, Western China, from GPS. J. Geophys. Res., 2001, 106(B12): 30607-30621.

[14] van der Voo R., Spakman W., Bijwaard H.. Tethyan Subducted Slabs under India. Earth and Planetary Science Letters, 1997, 171(1): 7-20.

[15] Wang Y., Xu H.. Convergence Rate of the India Plate to Eurasia Subduction beneath Qing-Zang Plateau-Inversion Result from the GPS Observed Data. Chinese J. Geophys., 2003, 46: 185-190.

[16] Wu H. Z., Ye P. S., Hu D. G.. Evolvement for Crustal Deformation and Tectonic Physiognomy, 2003, Beijing: Geological Publishing House 1-292.

[17] Xu J. R., Oike K.. Stress Characteristics in the Southern Segment of the North-South Seismic Belt. Acta Seismologica Sinica, 1995, 17(1): 31-40.

[18] Xu J. R., Yoshiteru K.. Geometry of Slab, Intraslab Stress Field and Its Tectonic Implication in the Nankai Trough, Japan. Earth, Planets and Space, 2002, 54(7): 733-742.

[19] Xu J. R., Zhao Z. X.. Continental Dynamics in the High Tibetan Plateau: Normal Faulting Type Earthquake Activities and Its Mechanism. Journal of Earth Science, 2009, 20(2): 484-492.

[20] Xu J. R., Zhao Z. X., Ishikawa Y.. Extensional Stress Field in the Central and Southern Qinghai-Tibetan Plateau and Dynamic Mechanism of Geothermic Anomaly in the Yangbajain Area. Chinese J. Geophys., 2005, 48(4): 861-869.

[21] Xu J. R., Zhao Z. X., Ishikawa Y., . Properties of the Stress Field in and around West China Derived from Earthquake Mechanism Solutions. Bulletin of the Disaster Prevention Research Institute, 1988, 38: 49-78.

[22] Xu Z. H.. A Present-Day Tectonic Stress Map for Eastern Asia Region. Acta Seismologica Sinica, 2001, 23(5): 524-533.

[23] Yang G. H., Li Y. X., Han Y. P., . Current Horizontal Strain Field in Chinese Mainland Derived from GPS Data. Acat Seismologica Sinica, 2002, 24: 338-347.

[24] Yeats R. S., Lillie R. J.. Contemporary Tectonics of the Himalaya Frontal Fault System: Folds, Blind Thrusts, and the 1905 Kangra Earthquake. J. Structural Geology, 1991, 13(2): 215-225.

[25] Zeng Z. S., Ding Z. F., Wu Q. J., . Seismological Evidence for Multiple Incomplete Crustal Subductions in the Himalayas and Southern Tibet, China. Chinese J. Geophys., 2000, 43(6): 780-797.

[26] Zhang P. Z., Shen Z. K., Wang M., . Continuous Deformation of the Tibetan Plateau from Global Positioning System Data. Geology, 2004, 32(9): 809-812.

[27] Zhao Z. X., Kazuo M., Kazuo O., . Regional Characteristics of Temporal Variation of Seismic Activity in East Asia and Their Mutual Relations: 1 Regions from North China to the Japan Trench. Zisin, 1987, 40(3): 383-396.

[28] Zhao Z. X., Kazuo M., Kazuo O., . Regional Characteristics of Temporal Variation of Seismic Activity in East Asia and Their Mutual Relations: 2 Regions from Taiwan to Southern China. Zisin, 1987, 40(4): 593-604.

[29] Zhao Z. X., Kazuo M., Kazuo O., . Regional Characteristics of Temporal Variation of Seismic Activity in East Asia and Their Mutual Relations: West China and Its Neighboring Regions. Zisin, 1988, 41(3): 389-400.

[30] Zhao Z. X., Oike K., Matsumura K., . Stress Field in the Continental Part of China Derived from Temporal Variations of Seismic Activity. Tectonophysics, 1990, 178(2–4): 357-372.