Abstract
Tectonic evolution of the Tethys and the boundary between the Gondwanaland and the Eurasia during the Carboniferous and Permian remain hotly debated. Qiangtang region in the Qinghai-Tibet Plateau may be a key place to study these problems. A paleomagnetic study was conducted on the Late Paleozoic rocks in the northern Qiangtang region (33.7°N, 86.7°W), Tibet. Two sites (21 samples) in the Upper Carboniferous, eleven sites (101 samples) in the Permian, and two sites (16 samples) in the Lower Triassic were investigated. The rock magnetic data revealed hematite and magnetite as the main magnetic carriers. In stepwise thermal demagnetization and/or combined alternating field (AC) demagnetization, two characteristic components in the majority of the samples were identified as (1) the Low-temperature Component (LTC), characterized by northerly declination and moderate to steep inclination, corresponding to a pole position overlay with the present North Pole. A minority of the samples present single component, and their directions are the same as (2) the High-temperature Component (HTC) of double components. The combined single-component and HTC data of the Permian can pass the R-test at 95% level and the F-test at 99% level, as well as the BC-test. The pole position from the Late Carboniferous is at 31.8°S, 45.7°E with dp=2.1, dm=3.9, that from the Early and Middle (Late) Permian is at 31.7°S, 46.8°E with dp=9.2, dm=16.9 (34.4°N, 54.1°E with dp=6.9, dm=12.5) respectively, and that from the Early Triassic is at 16.9°S, 22.5°E with dp=4.9, dm=9.2. These pole positions are different from the other poles for the Qiangtang Block, which suggests the single-component and HTC directions are probably a primary magnetization and the northern Qiangtang Block was paleogeographically situated at low latitudes in the Northern Hemisphere in the Late Paleozoic.
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References
Li C. A review on 20 years’ study of the Longmu Co-Shuanghu-Lancang River suture zone in Qinghai-Xizang (Tibet) Plateau (in Chinese). Geol Rev, 2008, 54: 105–119
Li C, Zhai G Y, Wang L Q, et al. An important window for understanding the Qinghai-Tibet Plateau—A review on research progress in recent years of Qiangtang area, Tibet, China (in Chinese). Geol Bull Chin, 2009, 28: 1169–1177
Ren J S, Xiao L W. Lifting the mysterious veil of the tectonics of the Qinghai-Tibet Plateau by 1:25000000 geological mapping (in Chinese). Geol Bull Chin, 2004, 23: 1–11
Liu C Y, Yang X K, Ren Z L, et al. Structural framework and its evolution in Chasang area of Qiangtang Basin in northern Tibet. Sci China Ser D-Earth Sci, 2001, 44(Suppl): 18–26
Pan G T, Wang L Q, Zhu D C. Thoughts on some important scientific problems in regional geological of the Qinghai-Tibet Plateau (in Chinese). Geol Bull Chin, 2004, 23: 12–19
Li R S, Yang Y C, Meng Y. Main results and progress in 1:250000 regional geological survey of the northern Qinghai-Tibet Plateau (in Chinese). Geol Bull Chin, 2004, 23: 421–426
Wang L Q, Zhu D C, Pan G T. Primary results and progress of regional geological survey (1:250000): The south of Qinghai-Tibet Plateau (in Chinese). Geol Bull Chin, 2004, 23: 413–420
Wang L Q, Pan G T, Li C, et al. SHRIMP U-Pb zircon dating of Eopaleozoic cumulate in Guoganjianian Mt. from central Qiangtang area of northern Tibet—Considering the evolvement of Proto- and Paleo-Tethys (in Chinese). Geol Bull Chin, 2008, 27: 2045–2056
Wu H N, Liu C Y, Zhang X H, et al. Study of the tectonic evolution of the Qaidam Basin, northwestern China, by paleomagnetic data. Sci China Ser D-Earth Sci, 1997, 27: 9–14
Fang D J, Wang P Y, Shen Z Y, et al. Cenozoic paleomagnetic results and phanerozoic apparent polar wandering path of Tarim Block. Sci China Ser D-Earth Sci, 1998, 41(Suppl 2): 105–112
Huang B C, Wang Y C, Zhu R X. New paleomagnetic and magnetic fabric results for Early Cretaceous rocks from the Turfan intramontane basin, east Tianshan of northwest China. Sci China Ser D-Earth Sci, 2004, 47: 540–550
Dong X B, Yang H X, Li P W. The paleomagnetic study of terrane tectonics in geoscience transection from Golmud to Ejin Qi (in Chinese). Acta Geophys Sin, 1995, 38(Suppl 2): 71–85
Li Y A, Li Q, Zhang H, et al. Palaeomagnetic study of Tarim and its adjacent area as well as the formation and evolution of Tarim Basin (in Chinese). Xinjiang Geol, 1995, 13: 293–376
Li P W, Gao R, Cui J W, et al. Paleomagnetic results from the Three Rivers Region, S W China: Implications for the collisional and accretionary history (in Chinese). Acta Geosci Sin, 2005, 26: 387–404
Sun L S, Huang B C. New paleomagnetic result for Ordovician rocks from the Tarim Block, Northwest China and its tectonic implications (in Chinese). Chin J Geophys, 2009, 52: 1836–1848
Li P W, Gao R, Guan Y, et al. Paleomagnetic constraints on the closure time of Paleo-Tethys: Implications for the tectonic setting of formation of Triassic Songpan-Ganzi flysch complex. Acta Geosci Sin, 2009, 30: 39–50
Yin J Y, Sun Z M, Yang Z Y, et al. Cretaceous and early Tertiary paleomagnetic results from the Lanping Basin and its geological implications (in Chinese). Chin J Geophys, 1999, 42: 648–659
Chang C F. Tethys and the evolutional characteristics of collision orogen in Qinghai-Tibet Plateau (in Chinese). In: Xu G Z, Chang C F, eds. Tectonics and Resources of Continental Lithosphere. Beijing: Ocean Press, 1992. 1–8
Deng W M. Palaeotethyan sutures and the “northern boundary of Gondwana land” in Qinghai-Tibet Plateau (in Chinese). In: Zhang Q, ed. Ophiolites and the Research on Earth Dynamics. Beijing: Geological Publishing House, 1996. 172–176
Yuan X C, Li T D, Xiao X C, et al. 3D lithospheric structure of the Qinghai-Tibet Plateau and hydraulic pressure machine model of the plateau uplift (in Chinese). Geol Chin, 2006, 33: 711–729
Xu Z Q, Yang J S, Li H B, et al. The Qinghai-Tibet Plateau and continental dynandcs: A review on terrain tectonica, conisional orogenesis, and processes and mechanisms for the rise of the Plateau (in Chinese). Geol Chin, 2006, 33: 221–238
Li C, Huang X P, Zhai Q G, et al. The Longmu Co-Shuanghu-Jitang plate suture and the northern boundary of Gondwanaland in the Qinghai-Tibet plateau (in Chinese). Earth Sci Front, 2006, 13: 136–147
Pan G T, Li X Z, Wang L Q, et al. Preliminary division of tectonic units of the Qinghai-Tibet Plateau and its adjacent regions (in Chinese). Geol Bull Chin, 2002, 21: 701–707
Zhang Y C, Yuan D X, Zhai Q G. The Carboniferous and Permian sequences in north and south of the Longmucuo-Shuanghu suture zone in Tibet. Acta Geosci Sin, 2009, 30(Suppl 1): 94–96
Li Y L, Wang C S, Huang J J. Deformation characteristics and finalizing age of the folds in the Qiangtang Basin and their relations to oil and gas accumulation (in Chinese). Oil Gas Geol, 2008, 29: 283–290
Lei Z Y, Li Y T, Liu Z, et al. Structural deformation and dynamic mechanism of the Qiangtang Basin, north Tibet (in Chinese). Geol Rev, 2001, 47: 415–419
Zhu R X, Huang B C, Pan Y X, et al. A brief guide to the laboratory of bock magnetism and paleomagnetism at the institute of geology and geophysics, Chinese Academy of Sciences (in Chinese). Prog Geophys, 2003, 18: 177–181
Lowrie W. Identification of ferromagnetic minerals in a rock coercivity and unblocking temperature properties. Geophys Res Lett, 1990, 17: 159–162
Zijderveld J D A. A demagnetization of rocks: Analysis of results. In: Collinson D W, Creer K M, Runcorn S K, eds. Methods on Paleomagnetic. New York: Elsevier, 1967. 245–286
Kirschvink J K. The least-squares line and plane and the analysis of paleomagnetic data. Geophys J R Astron Soc, 1980, 62: 699–718
Halls H C. The use of converging remagnetization circles in paleomagnetism. Phys Earth Planet Inter, 1978, 16: 1–11
Fisher R A. Dispersion on a sphere. Proc R Soc Lond Ser A, 1953, 217: 295–305
McFadden P L, McElhinny M W. Classification of the reversal test in paleomagnetism. Geophys J Int, 1990, 103: 725–729
McElhinny M W. Statistical significance of the fold test in paleomagnetism. Geophys J R Astron Soc, 1964, 8: 338–340
Watson G S, Enkin R J. The fold test in paleomagnetism as a parameter estimation problem. Geophys Res Lett, 1993, 20: 2135–2137
Li C, Zhai Q G, Cheng L R, et al. Thought on some key geological problems in the Qiangtang area, Qinghai-Tibet Plateau (in Chinese). Geol Bull Chin, 2005, 24: 295–301
He Z H, Li C, Yang D M, et al. The tectonic-sedimentary feature and evolution of QiangTang Basin in northern Tibet (in Chinese). J Changchun Univ Sci Tech, 2000, 30: 347–352
Zhou Y X, Lu L Z, Zhang B M. Paleomagnetic polarity of the permian emeishan basalt in scichuan (in Chinese). Geol Rev, 1986, 32: 465–469
McElhinny M W. Palaeomagnetism and plate tectonics. Cambridge: Cambridge University Press, 1973. 1–358
Van der Voo R. The reliability of paleomagnetic data. Tectonophysics, 1990, 184: 1–9
Cheng G L. Trial criteria of reliability for Paleomagnetic data (in Chinese). Acta Geophys Sin, 1993, 36: 121–123
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Cheng, X., Wu, H., Guo, Q. et al. Paleomagnetic results of Late Paleozoic rocks from northern Qiangtang Block in Qinghai-Tibet Plateau, China. Sci. China Earth Sci. 55, 67–75 (2012). https://doi.org/10.1007/s11430-011-4287-x
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DOI: https://doi.org/10.1007/s11430-011-4287-x