Late Oligocene-Early Miocene thrusting in southern East Kunlun Mountains, northern Tibetan plateau

Abstract

Southward thrusting occurred in Late Oligocene-Early Miocene in southern East Kunlun (昆仑) Mountains formed the South Kunlun thrust (SKT). Permian strata and Triassic rocks were thrusted over the Paleocene-Eocene red-beds of Fenghuoshan (风火山) Group and Oligocene brownish red conglomerate and sandstone of Yaxicuo (雅西错) Group along SKT faults, formed tectonic slices, low-angle thrust faults, multi-scaled outliers, and nappe structures in south of Middle Kunlun fault (MKF). In addition, SKT displacement or shortening is estimated to be ∼(30–35) km across Dongdatan (东大滩) valley and East Wenquan (温泉) basin. ³⁹Ar-⁴⁰Ar dating of chlorite of ductile shear zone along front thrust fault indicates that SKT thrusting occurred at 26.5±2.7 Ma, and fission track dating of apatite from mylonitic granite in SKT gives the age 26±2 Ma, corresponding to initial time of rapid uplift of East Kunlun Mountains. Thrust faults and folds of SKT were covered unconformably by Late Miocene lacustrine strata, and major thrusting of SKT ended before 13.5–14.5 Ma according to regional chronological data in northern Tibetan plateau.

Keywords

South Kunlun thrust (SKT) / thrusting and folding / chronological constrain / northern Tibetan plateau

References

[1] Blisniuk M. P., Hacker R. B., Glodny J., . Normal Faulting in Central Tibet since at least 13.5 Ma Ago. Nature, 2001, 412: 628-632.

[2] Chai Y. L., Feng B. G., Yang J. S.. CGQXP Committee Features and Origin of Xidatan Granite in Middle East Kunlun Mountains. Contribution to Geology of Qinghai-Xizang (Tibet) Plateau (15), 1984, Beijing: Geological Publishing House 79-90.

[3] Chen W., Guo Y. R., Cui B., . Research on Ages of Deformation and Metamorphism of the Xidatan Rock Series, East Kunlun Mountains. Geological Review, 2002, 48(Suppl.): 103-109.

[4] Cui J. W., Wu C. D., Zhu H., . Lithosphere Center of CAGSInstitute of Geology of MGMR Deformation and Its Geodynamic Cause of Lithosphere of the Tibetan Plateau. Structures, Tectonics and Evolution of Lithosphere of the Tibetan Plateau, 1996, Beijing: Geological Publishing House 58-59.

[5] Cui, S. Q., Wu, Z. H., 1997. On the Mesozoic and Cenozoic Intracontinental Orogenesis of Yanshan Area, China. Proc. of 30th Int’l. Geol. Congr., 277–292

[6] Cui Z. Z.. Lithosphere Center of CAGSInstitute of Geology of MGMR Deep Tectonics and Velocity Structure of Crust-Upper Mantle of the Tibetan Plateau. Structures, Tectonics and Evolution of Lithosphere of the Tibetan Plateau, 1996, Beijing: Geological Publishing House 126-137.

[7] Kidd W. S. F., Molnar P.. Quaternary and Present Active Faults of Lhasa-Golmud of the Tibetan Plateau. Roy. Soc. London A, 1990, 327: 332-352.

[8] Kidd W. S. F., Pan Y., Chang C., . Geological Mapping of the 1985 Chinese-British Tibetan (Xizang- Qinghai) Plateau Geotraverse Route. Phil. Trans. Roy. Soc. London A, 1988, 327: 287-305.

[9] Li J. D., Bai D. Y., Wang S. H.. Time of Volcanic Rocks and Peneplanation in Congmeishan Area, North Tibetan Plateau. Geological Bulletin of China, 2004, 23(7): 670-675.

[10] Li T. D.. Yadong-Golmud Geoscientific Transection to Show Uplift of the Tibetan Plateau. Earth Science— Journal of China University of Geosciences, 1997, 21(1): 34-39.

[11] Li T. D., Xiao X. C.. Lithosphere Center of CAGSInstitute of Geology of MGMR Analyses on Terrane Tectonics of the Tibetan Plateau. Strutures, Tectonics and Evolution of Lithosphere of the Tibetan Plateau, 1996, Beijing: Geological Publishing House 6-13.

[12] Lin A. M., Fu B. H., Guo J. M., . Co-seismic Strike-Slip and Rupture Length Produced by the 2001 Ms 8.1 Central Kunlun Earthquake. Science, 2002, 296(5575): 2015-2017.

[13] Pan G. T., Ding J., Yao D. S., . Geological Map of Qinghai-Xizang (Tibet) Plateau and Adjacent Areas (1:1 500 000) Attached with a Guidebook, 2004, Chengdu: Chengdu Cartographic Publishing House 1-48.

[14] Pan Y. S., Kong X. R.. Lithosphere Structure, Evolution and Dynamics of Qinghai-Xizang (Tibetan) Plateau, 1998, Guangzhou: Guangdong Science and Technology Press 1-428.

[15] Qinghai Bureau of GeologyMineral Resources Regional Geology of Qinghai Province, 1991, Beijing: Geological Publishing House 1-662.

[16] Seismological Bureau of Qinghai ProvinceInstitute of Crust Stress East Kunlun Active Fault, 1999, Beijing: Seismological Press 1-186.

[17] Tapponnier P., Xu Z., Roger F., . Oblique Stepwise Rise and Growth of the Tibet Plateau. Science, 2001, 294(5547): 1671-1677.

[18] Unsworth M., Wei W. B., Alan G. J., . Crustal and Upper Mantle Structure of Northern Tibet Imaged with Magnetotelluric Data. Journal of Geophysical Research, 2004, 109(B2): 1-18.

[19] van der Woerd J., Ryerson F. J., Tapponnier P., . Uniform Slip-Rate along the Kunlun Fault: Implications for Seismic Behaviour and Large-Scale Tectonics. Geophysical Research Letters, 2000, 27(16): 2353-2356.

[20] van der Woerd J., Ryerson F. J., Tapponnier P., . Holocene Left-Slip Rate Determined by Cosmogenic Surface Dating on the Xidatan Segment of the Kunlun Fault (Qinghai, China). Geology, 1998, 26(8): 695-698.

[21] van der Woerd J., Tapponnier P., Ryerson F. J., . Uniform Postglacial Slip-Rate along the Central 600 km of the Kunlun Fault (Tibet), from ²⁶Al, ¹⁰Be and ¹⁴C Dating of Riser Offsets, and Climatic Origin of the Regional Morphology. Geophysical Journal International, 2002, 148(3): 356-388.

[22] Wang C. S., Liu Z. F., Yi H. S., . Tertiary Crustal Shortening and Peneplanation in the Hoh Xil Region: Implications for Tectonic History of the Northern Tibetan Plateau. Journal of Asian Earth Sciences, 2002, 20(3): 211-223.

[23] Wei W., Unsworth M., Jones A., . Detection of Widespread Fluids in the Tibetan Crust by Magnetotelluric Studies. Science, 2002, 292(5517): 716-718.

[24] Wu Z. H., Barosh J. P., Wu Zh. H., . Vast Early Miocene Lakes of the Central Tibetan Plateau. Geological Society of America Bulletin, 2008, 120(9–10): 1326-1337.

[25] Wu Z. H., Ye P. S., Zhao W. J., . Late Cenozoic Overthrust System in the Southern East Kunlun Mountains, China. Geological Bulletin of China, 2007, 26(4): 448-456.

[26] Wu Z. H., Hu D. G., Wu Z. H., . Pressure Ridges and Their Ages of the Xidatan Strike-Slip Fault in South Kunlun Mts. Geological Review, 2006, 52(1): 15-24.

[27] Wu Z. H., Hu D. G., Song B., . Ages and Thermo-chronological Evolution of the Granite in Northern Xidatan Basin, South Kunlun Mountains. Acta Geologica Sinica, 2005, 79(5): 628-635.

[28] Wu Z. H., Barosh J. P., Hu D. G., . Hazards Posed by Active Major Faults along the Golmud-Lhasa Railway Route, Tibetan Plateau, China. Engineering Geology, 2004, 74(3–4): 163-182.

[29] Xu Z. Q., Li H. B., Yang J. S., . A Large Transpression Zone at the South Margin of the East Kunlun Mountains and Oblique Subduction. Acta Geoscientia Sinica, 2001, 75(2): 156-164.

[30] Yin A., Harrison T. M.. Geologic Evolution of the Himalayan- Tibetan Orogen. Annu. Rev. Earth Planet. Sci. Lett., 2000, 28: 211-280.

[31] Yin H. F., Zhang K. X., Wang G. C., . Regional Geological Report of Donggai Conag Hu Map, 2003, Wuhan: China University of Geosciences Press 282-343.