Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (25) Citing Articles via Google Scholar Google Scholar Articles by Kapp, P. Articles by Ding, L. Search for Related Content GeoRef GeoRef Citation

Cretaceous-Tertiary shortening, basin development, and volcanism in central Tibet

Paul Kapp^,1, An Yin^,2, T. Mark Harrison^,2 and Lin Ding^#,3

¹ Department of Geosciences, University of Arizona, Tucson, Arizona 85721-0077, USA
² Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA
³ Institute of Tibetan Plateau Research and Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China

The geologic map pattern of the Qiangtang terrane in central Tibet defines a >600-km-long and up to 270-km-wide east-plunging structural culmination. It is characterized by early Mesozoic blueschist-bearing mélange and upper Paleozoic strata in the core and mainly Triassic–Jurassic strata along the limbs. In the western Qiangtang terrane (84°E), the culmination is unconformably overlain by weakly deformed mid-Cretaceous volcanic flows and tuffs. Along the Bangong suture to the south (32°N, 84°E), mid-Cretaceous nonmarine red beds and volcanic rocks lie unconformably on Jurassic suture zone rocks. These relationships demonstrate that west-central Tibet was above sea level during the mid-Cretaceous and experienced significant denudation prior to mid-Cretaceous time. Growth of the Qiangtang culmination is inferred to have initiated during southward emplacement of a thrust sheet of early Mesozoic mélange and upper Paleozoic strata during the Early Cretaceous Lhasa-Qiangtang collision. The north-south width of the inferred thrust sheet provides a minimum slip estimate of 150 km at 84°E, decreasing eastward to 70 km at 87°E.

Paleogene deformation in the Qiangtang terrane is characterized by widely distributed, mainly north-dipping thrust faults that cut Eocene–Oligocene red beds and volcanic rocks in their footwall. Along the Bangong suture, the north-dipping Shiquanhe-Gaize-Amdo thrust system cuts 64 and 43 m.y. old volcanic tuffs in its footwall and accommodated >40 km of post–mid-Cretaceous shortening. The Tertiary south-dipping Gaize–Siling Co backthrust bounds the southern margin of the Bangong suture and marks the northernmost limit of mid-Cretaceous marine strata in central Tibet. Cretaceous deformation and denudation in central Tibet is attributed to northward underthrusting of the Lhasa terrane beneath the Qiangtang terrane along the Bangong suture. This model implies that (1) Cretaceous strata along the Bangong suture and in the northern Lhasa terrane were deposited in a flexural foreland basin system and derived at least in part from the Qiangtang terrane, and (2) the central Tibetan crust was thickened substantially prior to the Indo-Asian collision. Although its magnitude is poorly known, Tertiary shortening in the Qiangtang terrane is more prevalent than in the Lhasa terrane; this difference may be attributed to the presence of underthrust mélange in the deeper central Tibetan crust, which would have made it weaker than the Lhasa terrane during the Indo-Asian collision.

Key Words: Tibet • plateau formation • continental collision • underthrusting • suture • shortening

This article has been cited by other articles:

				C. Studnicki-Gizbert, B.C. Burchfiel, Z. Li, and Z. Chen Early Tertiary Gonjo basin, eastern Tibet: Sedimentary and structural record of the early history of India-Asia collision Geosphere, August 1, 2008; 4(4): 713 - 735. [Abstract] [Full Text] [PDF]

				C. Wang, X. Zhao, Z. Liu, P. C. Lippert, S. A. Graham, R. S. Coe, H. Yi, L. Zhu, S. Liu, and Y. Li Constraints on the early uplift history of the Tibetan Plateau PNAS, April 1, 2008; 105(13): 4987 - 4992. [Abstract] [Full Text] [PDF]

				A. L. Leier, P. G. DeCelles, P. Kapp, and G. E. Gehrels Lower Cretaceous Strata in the Lhasa Terrane, Tibet, with Implications for Understanding the Early Tectonic History of the Tibetan Plateau Journal of Sedimentary Research, October 1, 2007; 77(10): 809 - 825. [Abstract] [Full Text] [PDF]

				P. Kapp, P. G. DeCelles, G. E. Gehrels, M. Heizler, and L. Ding Geological records of the Lhasa-Qiangtang and Indo-Asian collisions in the Nima area of central Tibet GSA Bulletin, July 1, 2007; 119(7-8): 917 - 933. [Abstract] [Full Text] [PDF]

				P.G. DeCelles, P. Kapp, L. Ding, and G.E. Gehrels Late Cretaceous to middle Tertiary basin evolution in the central Tibetan Plateau: Changing environments in response to tectonic partitioning, aridification, and regional elevation gain GSA Bulletin, May 1, 2007; 119(5-6): 654 - 680. [Abstract] [Full Text] [PDF]

				M.-F. Chu, S.-L. Chung, B. Song, D. Liu, S. Y. O'Reilly, N. J. Pearson, J. Ji, and D.-J. Wen Zircon U-Pb and Hf isotope constraints on the Mesozoic tectonics and crustal evolution of southern Tibet Geology, September 1, 2006; 34(9): 745 - 748. [Abstract] [Full Text] [PDF]

				J. H. Guynn, P. Kapp, A. Pullen, M. Heizler, G. Gehrels, and L. Ding Tibetan basement rocks near Amdo reveal "missing" Mesozoic tectonism along the Bangong suture, central Tibet Geology, June 1, 2006; 34(6): 505 - 508. [Abstract] [Full Text] [PDF]

				M. S. Spurlin, A. Yin, B. K. Horton, J. Zhou, and J. Wang Structural evolution of the Yushu-Nangqian region and its relationship to syncollisional igneous activity, east-central Tibet GSA Bulletin, September 1, 2005; 117(9-10): 1293 - 1317. [Abstract] [Full Text] [PDF]