Neogene surface uplift of the Lunpola Basin in Central Tibet: Implications for uplifting and flattening of orogenic plateaus

Lin Li, Carmala N. Garzione, Haijian Lu, Jay Quade

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Orogenic plateaus are known for their high and flat interiors, but the mechanism by which the high-elevation, low-relief topography is formed remains controversial. The Tibetan Plateau, which may have had a broad central valley along the Bangong suture zone during the Eocene, is a valuable research target to test potential driving mechanisms. In this study, we report both stable and clumped isotopes of lacustrine carbonates of the Lunpola Basin to better constrain the paleoelevation history of the Bangong suture zone in Central Tibet. Covariations of the stable oxygen and carbon isotopes indicate increasing evaporative enrichment of lake water reflecting enhanced aridity from the middle Eocene to early Miocene. After removing altered samples using multiple diagenesis screening methods and the potential influence of global cooling, our clumped isotope temperatures indicate consistent paleoelevations of 2.2 ± 1.1 km at 40–20 Ma, followed by an abrupt 1.4 ± 0.8 km surface uplift at 20–19 Ma and an additional 1.0 ± 0.7 km surface uplift between 16 Ma and the present to achieve the current high elevation of ∼4.6 km. These new paleoelevation results suggest that the Neogene was the primary period of topographic growth for the Lunpola Basin, which contradicts previous inferences emphasizing Paleogene growth. We argue that the Bangong suture zone in Central Tibet was probably a broad low-elevation valley throughout the Paleogene and uplifted mainly during the Neogene by multiple subsurface geodynamic processes, including convective removal of the lower lithosphere and middle–lower crustal flow. A comparison with the north-central Tibet Hoh Xil Basin and South American Altiplano indicates that these subsurface geodynamic processes may be common for uplifting and flattening orogenic plateaus.

Original languageEnglish (US)
Article number118961
JournalEarth and Planetary Science Letters
Volume646
DOIs
StatePublished - Nov 15 2024
Externally publishedYes

Keywords

  • Central Tibet
  • Clumped isotope
  • Geodynamics
  • Lacustrine carbonate
  • Orogenic plateau
  • Paleoelevation

ASJC Scopus subject areas

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

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