Search

The timing, kinematics, and geodynamic evolution of the India-Asia continental collision are crucial to understanding the geological and geomorphological evolution of the Himalayan-Tibetan orogen. However, the debate over how and when the collision occurred persists due to disputes concerning the reliability of paleomagnetic data obtained on both sides of the suture zone. This paper presents a comprehensive analysis and evaluation of paleomagnetic studies to address this controversial issue. The study focuses on well-preserved Cretaceous-Paleocene rocks from the Lhasa and Tethyan Himalaya (TH) terranes over the past two decades. We conclude that: (1) the paleomagnetic data of the Linzizong Group of the Lhasa Terrane and the Zongpu Formation of the TH are in their primary origin and can be used for tectonic reconstruction; (2) the Tethys Himalaya Basin (THB) was generated due to the rifting of the TH from Greater India before the Late Cretaceous; (3) the southern margin of Asia was aligned in the NW-SE direction before the India-Asia collision. The study suggests a quasi-synchronous multi-stage collision where the TH collided with the Trans-Tethyan subduction system in Late Cretaceous-Early Paleocene times (∼65 Ma), followed by collision with Asia at 56–59 Ma. Finally, the India Craton collided with the TH, resulting in the synchronous closure of the THB at approximately 40 Ma. [ABSTRACT FROM AUTHOR]

Continental evolution is responsible for the evolution of orogenic belts and sedimentary basins. The India–Asia convergence during the late Mesozoic to Cenozoic and the resulting tectono-sedimentary processes in the Tibetan Plateau and and its environs are among the most spectacular manifestations of continental evolution and sedimentary basin formation in recent Earth history. The aim of this special issue is to explore continental evolution and sedimentary basins in central-southern Asia since the late Mesozoic, with a main focus on the India–Asia convergence and the resulting tectono-sedimentary, tectono-geomorphologic, and paleoclimatic/paleoenvironmental processes in the Tibetan Plateau and its environs during the late Cretaceous to Neogene. The issue comprises ten papers that address the significance of Continental Evolution and Sedimentary Basins of the Tibetan Plateau and its Environs since the middle Cretaceous, and that fall into three categories. (i) The first category addresses the paleogeography of the southern-central Tibetan Plateau during the Cretaceous to Paleogene. These studies decipher the multistage collision of India with Asia, the opening and closing of ocean basins, and the tectonic evolution of the major blocks (such as Tibetan Himalaya, Lhasa, and southern/western Qiangtang) and especially of the major Himalayan tectonostratigraphic units during the convergence history between India and Asia. (ii) The second category addresses the tectono-sedimentary and tectono-geomorphologic evolution of the eastern and northeastern margins of the Tibetan Plateau during the late Cretaceous to Neogene. (iii) The third and the final category addresses the tectono-sedimentary basin filling and/or paleoenvironmental processes during the late Eocene to Pliocene, which are recorded in the intermontane Kuche and Tajik basins in central Asia and thus may reflect the far-field influence of the post-collisional India–Asia convergence on these sedimentary basins. • Continental evolution is responsible for the evolution of orogenic belts and sedimentary basins. The India–Asia convergence during the late Mesozoic to Cenozoic and the resulting tectono-sedimentary processes in the Tibetan Plateau and and its environs are among the most spectacular manifestations of continental evolution and sedimentary basin formation in recent Earth history. • The paleogeography of the southern-central Tibetan Plateau during the Cretaceous to Paleogene was shaped by the multistage collision of Inida with Asia, the opening and closing of ocean basins, and the tectonic evolution of the major blocks (such as Tibetan Himalaya, Lhasa, and southern/western Qiangtang) and especially of the major Himalayan tectonostratigraphic units during the convergence history between India and Asia. • The India–Asia collision and ongoing convergence led to southeastward crustal extrusion, eastward and northeastward crustal growth and expansion of the Tibetan Plateau, and widespread crustal deformation surrounding the plateau. The concurrent uplift, denudation, and sedimentation have played important roles in shaping the mountain topography of the orogenic plateau margins. • The tectono-sedimentary filling and/or paleoenvironmental processes recorded in the intermontane Kuche and Tajik basins in central Asia during the late Eocene to Pliocene may reflect the far-field influence of the post-collisional India–Asia convergence on the sedimentary basins in central Asia and/or the interplay between tectonics and climate in the Asian interior. [ABSTRACT FROM AUTHOR]

Climate on the Tibetan Plateau is often considered sensitive to global changes, yet the degree of sensitivity in different spaces and seasons prior to instrumental records is not clear. In this paper, we studied tree-ring maximum latewood density (MXD) to examine the late-summer (August–September) temperature variation over the past two and half centuries on the eastern Tibetan Plateau. The MXD regional chronology was established from 109 tree-ring samples of Balfour spruce [ Picea likiangensis var. balfouriana (Rehd. et Wils.)] at four high elevation sites. The chronology exhibited a high correlation ( r = 0.82, n = 56, p < 0.001) with the mean August–September temperature. Using the tree-ring data, we reconstructed the late-summer temperature for the period A.D. 1765–2009. The reconstruction accounted for 71.4% of the variance in instrumental temperature in the period 1954–2009. The reconstructed temperature did not show a warming trend in the past 250 years, suggesting a unique characteristic of late-summer temperature variability in the study region of the Tibetan Plateau. Our tree-ring data are useful for further understanding of the plateau's thermal condition in late summer and its role in regulating southward retreat of the Southwest Asian monsoon. [ABSTRACT FROM AUTHOR]