Multiple episodes of fast exhumation since Cretaceous in southeast Tibet, revealed by low-temperature thermochronology

Jing Liu-Zeng, Jinyu Zhang, Devin McPhillips, Peter Reiners, Wei Wang, Raphael Pik, Lingsen Zeng, Greg Hoke, Kejia Xie, Ping Xiao, Dewen Zheng, Yukui Ge

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

The 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 (∼28.5°N) and Weixi (∼27.5°N). The two transects share a similar exhumation history, with two episodes of relatively fast exhumation (∼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.

Original languageEnglish (US)
Pages (from-to)62-76
Number of pages15
JournalEarth and Planetary Science Letters
Volume490
DOIs
StatePublished - May 15 2018

Keywords

  • Three Rivers region
  • erosion rate
  • exhumation
  • low-temperature thermochronometry
  • southeast Tibet

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Multiple episodes of fast exhumation since Cretaceous in southeast Tibet, revealed by low-temperature thermochronology'. Together they form a unique fingerprint.

  • Cite this

    Liu-Zeng, J., Zhang, J., McPhillips, D., Reiners, P., Wang, W., Pik, R., Zeng, L., Hoke, G., Xie, K., Xiao, P., Zheng, D., & Ge, Y. (2018). Multiple episodes of fast exhumation since Cretaceous in southeast Tibet, revealed by low-temperature thermochronology. Earth and Planetary Science Letters, 490, 62-76. https://doi.org/10.1016/j.epsl.2018.03.011