Multiple episodes of fast exhumation since Cretaceous in southeast Tibet, revealed by low-temperature thermochronology
AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherELSEVIER SCIENCE BV
CitationJing Liu-Zeng, Jinyu Zhang, Devin McPhillips, Peter Reiners, Wei Wang, Raphael Pik, Lingsen Zeng, Greg Hoke, Kejia Xie, Ping Xiao, Dewen Zheng, Yukui Ge, Multiple episodes of fast exhumation since Cretaceous in southeast Tibet, revealed by low-temperature thermochronology, Earth and Planetary Science Letters, pp 62-76, https://doi.org/10.1016/j.epsl.2018.03.011
Rights© 2018 Elsevier B.V. All rights reserved.
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AbstractThe southeast margin of the Tibetan plateau is characterized by deeply incised river valleys separated by a perched low relief landscape that gently descends from the high Tibetan plateau towards the southeast. When and how this unique landscape formed is debated. The onset of increased river incision is often interpreted as a proxy for the timing of surface uplift. Here, apatite and zircon (U-Th)/He and apatite fission track thermochronometries are employed to map the spatial and temporal pattern of exhumation in the region. Vertical profiles of granitic rocks were collected near Deqin (similar to 28.5 degrees N) and Weixi (similar to 27.5 degrees N). The two transects share a similar exhumation history, with two episodes of relatively fast exhumation (similar to 100-300 m/Myr) in the Cenozoic: during the Paleocene to Eocene (60-40 Ma) and Miocene to present (20-0 Ma), separated by an intervening period of slow exhumation. A pulse of moderate to high exhumation (70-300 m/Myr) during the mid- to late-Cretaceous (120-80 Ma) is also present in the data. However, the rate and total amount of exhumation near Deqin is larger than at Weixi and is especially pronounced in the interval between 20 Ma to present. We interpret this difference as possibly related to differences in erosion rates between the Lancang (Deqin) and the Jinsha (Weixi) rivers. The Paleocene to Eocene episode of fast exhumation is likely in response to early Cenozoic deformation along tectonic boundary structures, related to the transpressional collision of the Indian plate with this region. Pre-Miocene episodes of fast exhumation corroborate recent paleoaltimetric studies, which show that the southeast margin of the Tibetan plateau was elevated prior to the Oligocene. (C) 2018 Elsevier B.V. All rights reserved.
Note24 month embargo; published online: 19 March 2018
VersionFinal accepted manuscript
SponsorsNational Key Research and Development Project of China [2016YFC0600310]; National Natural Science Foundation of China [41225010, 41502188]; State Key Laboratory of Earthquake Dynamics [LED2014A02]