Three-phase uplift of the Qinghai-Tibet plateau during the Cenozoic period: Igneous petrology constraints

  • Lai Shaocong 

Abstract

In northern Qinghai-Tibet plateau there are developed Cenozoic volcanic rocks. They constitute a trachybasalt-shoshonite-latite-trachydacite assemblage. According to the forming ages, three Cenozoic volcanic rock lithozones can be distinguished in the northern part of the plateau. Cenozoic volcanic rocks and muscovite/two-mica granites forming the three belts in pairs represent the northern and southern margins of the plateau in different periods. In fact, the tectonic setting of the northern part of the Qinghai-Tibet plateau is significantly different from that of the southern part—Himalayas. The southern part has experienced subduction and continent-continent collision. There are developed the Cenozoic S-type granites (muscovite/ two-mica granites) there. But the northern part is characterized by Cenozoic basaltic magmatism which obviously comes from the upper mantle. Slight doming of the upper mantle is recognized underneath the northern part of the plateau, which is the result of resistance of the Tarim plate to the north direction-sense movement of the Tibetan plate. And at the same time, the uplift machanism shows that the formation of the Qinghai-Tibet plateau involved three orogenic stages (35−23 Ma, 23−10 Ma and <2 Ma) of uplift in the vertical direction and extension in the horizontal direction with the Gangdise-Qiangtang orogenic belt as its core.

Key words

igneous rock orogenic belt uplift mechanism Qinghai-Tibet plateau 

References

  1. Deng Jinfu, Zhao Hailing, Lai Shaocong et al., 1994, Muscovite/two-mica granite formation and the intracontinental subduction: Journal of China University of Geosciences, v. 19, n. 2, p. 139–147.Google Scholar
  2. Deng Jinfu, Zhao Hailing, Mo Xuanxue et al., 1996, Contineneal roots-plume tectonics of China—key to the continental dynamics: Beijing, Geological Publishing House, p. 17–26 (in Chinese).Google Scholar
  3. Gao Mingxiu, 1996, Study on the geodynamics of the south margin, Qinghai-Tibet plateau: Seismogeology, v. 18, n. 2, p. 143–155 (in Chinese).Google Scholar
  4. Gao Rui, 1995, Review of the geophysics investigations for crust and upper mantle of the Qinghai-Tibet plateau: China Geology, v. 18, n. 4, p. 26–28 (in Chinese).Google Scholar
  5. Kazuo, A. and T. Asahiko, 1992, Two-phase uplift of higher Himalayas since 17 Ma: Geology, v. 20, p. 391–394.CrossRefGoogle Scholar
  6. Lai Shaocong, 1996, Cenozoic volcanism and tectonic evolution in the northern margin of Qinghai-Tibet Plateau: Journal of Northwest University, v. 26, n. 1, p. 99–104.Google Scholar
  7. Lai Shaocong, Deng Jinfu, and Zhao Hailing, 1996, Volcanism and tectonic evolution in the northern margin of Qinghai-Tibet plateau: Xi’an, Science and Technology Press of Shaanxi Province, p. 95–133 (in Chinese).Google Scholar
  8. Lai Shaocong, 1995, Features of megacryst in cenozoic volcanic rocks from Hoh Xil and Mangkang lithodistricts, Qinghai-Tibet plateau: Journal of Northwest University, v. 25, n. 6, p. 701–704 (in Chinese).Google Scholar
  9. Li Tingdong, 1995, Uplift process and mechanism of th Qinghai-Tibet plateau: Acta Geoscientia Sinica, v. 16, n. 1, p. 1–9 (in Chinese).Google Scholar
  10. Morrison, G. W., 1980, Characteristics and tectonic setting of the shoshonite rock association: Lithos, v. 13, p. 97–108.CrossRefGoogle Scholar
  11. Nelson, K.D., W.J. Zhao, L.D. Brown et al., 1996, Partially molten middle crust beneath southern Tibet: synthesis of project INDEPTH result: Science, v. 274, p. 1684–1688.CrossRefGoogle Scholar
  12. Rat, S.L., W. Frisch, C. Chen et al., 1992, Deformation and motion along the southern margin of the Lhasa Block (Tibet) prior or and during the India-Asia collision: Journal of Geodynamics, v. 16, n. 1–2, p. 21–54.Google Scholar
  13. Wortel, M.J.R., U. Hansen, and R. Sabadini, 1992, Convective removal of thermal boundary layer of thickened continental lithosphere: a brief summary of causes and consequences with special reference to the Cenozoic tectonics of the Tibetan plateau and surrounding regions: Tectonophysics, v. 223, n. 1–2, p. 67–73.Google Scholar
  14. Wu Gongjian and Xiao Xuchang, 1996, Revealling the uplift of the Qinghai-Tibet plateau—Yadong-Geermu geoscience section: Earth Science—Journal of China University of Geosciences, v. 21, n. 1, p. 34–40 (in Chinese).Google Scholar
  15. Xiao Xuchang and Li Tingdong, 1998, The lithosphere structure, uplift mechanism and their influence on continental deformation of the Qinghai-Tibet plateau: Geology Review, v. 44, n. 1, p. 112 (in Chinese).Google Scholar
  16. Xie Guanghong, Liu Congqiang, Zengtian Zhangzheng et al., 1992, Geochemical features of the Cenozoic volcanic rocks from Qinghai-Tibet plateau and its adjacent area—evidence for existence of an ancient enrichment mantle, in Liu Ruoxin, ed., Geochemistry and Chronology of the Cenozoic Volcanic Rocks in China: Beijing, Seismic Publishing House, p. 400–427 (in Chinese).Google Scholar
  17. Xu Zhiqing and Jiang Men, 1996, Deep internal geophysics of the north part, Qinghai-Tibet plateau: Acta Geologica Sinica, v. 70, n. 3, p. 195–206 (in Chinese).Google Scholar
  18. Yamashita N., S. Sato, and M. Inomata, 1993, Qinghai-Tibet plateau: geology and its formation: Earth Science, v. 43, n. 5, p. 333–334.Google Scholar
  19. Zheng Jiandong, 1996, Discussion about the geodynamics at the northwest margin of the Qinghai-Tibet plateau: Seismogeology, v. 18, n. 2, p. 119–127 (in Chinese).Google Scholar

Copyright information

© Institute of Geochemistry, Chinese Academy of Sciences 2000

Authors and Affiliations

  • Lai Shaocong 
    • 1
  1. 1.Department of GeologyNorthwest UniversityXi’anChina

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