TY - JOUR

T1 - Late Cretaceous to Late Eocene Exhumation in the Nima Area, Central Tibet

T2 - Implications for Development of Low Relief Topography of the Tibetan Plateau

AU - Xue, Weiwei

AU - Najman, Yani

AU - Hu, Xiumian

AU - Persano, Cristina

AU - Stuart, Finlay

AU - Li, Wei

AU - Ma, Anlin

AU - Wang, Ying

N1 - An edited version of this paper was published by AGU. Copyright 2022 American Geophysical Union. Xue, W., Najman, Y., Hu, X., Persano, C., Stuart, F. M., Li, W., et al. (2022). Late Cretaceous to Late Eocene exhumation in the Nima area, central Tibet: Implications for development of low relief topography of the Tibetan Plateau. Tectonics, 41, e2021TC006989. https://doi.org/10.1029/2021TC006989

PY - 2022/3/31

Y1 - 2022/3/31

N2 - Much of the interior of the Tibetan Plateau is characterized by internal drainage, low relief topography, and high altitude. How and when this landscape formed is controversial. In this study, we use new zircon U-Pb data and low-temperature thermochronological data (apatite and zircon [U-Th/He], apatite fission track [AFT]) from the Late Cretaceous to Cenozoic Nima Basin sedimentary rocks and Xiabie granite in the adjacent Muggar Thrust hanging wall (part of the regional Shiquanhe-Gaize-Amdo thrust system), to determine the paleodrainage and timing of exhumation in the region. Individual AHe and ZHe cooling ages range from 9 to 60 Ma and 58 to 118 Ma, and the AFT ages range from 30 to 90 Ma. The thermal history derived from the Northern Nima Basin sediments and Xiabie granite require a period of exhumation between 70 and 40 Ma in the thrust fault hanging wall, and 40 and 30 Ma in the Nima Basin. Across the region, this event was followed by low rates of exhumation and the deposition of locally sourced sediment, lacustrine, and evaporitic deposits that are indicative of an internal drainage system. We suggest that the exhumation event is associated with development of thrust-elevated relief that may have disrupted the drainage network favoring the development of an endorheic system. This system, sediment accumulation, and/or post-30 Ma tectonic quiescence led to the generation of low relief topography.

AB - Much of the interior of the Tibetan Plateau is characterized by internal drainage, low relief topography, and high altitude. How and when this landscape formed is controversial. In this study, we use new zircon U-Pb data and low-temperature thermochronological data (apatite and zircon [U-Th/He], apatite fission track [AFT]) from the Late Cretaceous to Cenozoic Nima Basin sedimentary rocks and Xiabie granite in the adjacent Muggar Thrust hanging wall (part of the regional Shiquanhe-Gaize-Amdo thrust system), to determine the paleodrainage and timing of exhumation in the region. Individual AHe and ZHe cooling ages range from 9 to 60 Ma and 58 to 118 Ma, and the AFT ages range from 30 to 90 Ma. The thermal history derived from the Northern Nima Basin sediments and Xiabie granite require a period of exhumation between 70 and 40 Ma in the thrust fault hanging wall, and 40 and 30 Ma in the Nima Basin. Across the region, this event was followed by low rates of exhumation and the deposition of locally sourced sediment, lacustrine, and evaporitic deposits that are indicative of an internal drainage system. We suggest that the exhumation event is associated with development of thrust-elevated relief that may have disrupted the drainage network favoring the development of an endorheic system. This system, sediment accumulation, and/or post-30 Ma tectonic quiescence led to the generation of low relief topography.

U2 - 10.1029/2021tc006989

DO - 10.1029/2021tc006989

M3 - Journal article

VL - 41

JO - Tectonics

JF - Tectonics

SN - 0278-7407

IS - 3

M1 - e2021TC006989

ER -