Dating the incision of the Yangtze River gorge at the First Bend using three-nuclide burial ages
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Incision of the Yangtze River gorge is widely interpreted as evidence for lower crustal flow beneath the southeast margin of the Tibetan Plateau. Previous work focused on the onset of incision, but the duration of incision remains unknown. Here we present cosmogenic nuclide burial ages of sediments collected from caves on the walls of the gorge that show the gorge was incised ~1 km sometime between 18 and 9 Ma. Thereafter, incision slowed substantially. We resolve middle Miocene burial ages by using three nuclides and accounting for in situ muogenic production. This approach explains the absolute concentrations of 10Be, 26Al, and 21Ne, as well as 26Al/10Be and 21Ne/10Be ratios. A declining incision rate challenges existing geodynamic interpretations by suggesting that either (1) surface uplift has ceased immediately south of the plateau margin or (2) gorge incision is not a useful proxy for the timing of surface uplift.
Date Issued
2016-01-06
Date Acceptance
2015-12-09
Citation
Geophysical Research Letters, 2016, 43 (1), pp.101-110
ISSN
1944-8007
Publisher
American Geophysical Union (AGU)
Start Page
101
End Page
110
Journal / Book Title
Geophysical Research Letters
Volume
43
Issue
1
Copyright Statement
©2015. American Geophysical Union. All Rights Reserved.
Subjects
Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
cosmogenic nuclide
burial dating
Yangtze River
river incision
Tibetan Plateau
LOWER CRUSTAL FLOW
EASTERN TIBETAN PLATEAU
COSMOGENIC NUCLIDES
SURFACE UPLIFT
MARGIN
EVOLUTION
DEFORMATION
RADIONUCLIDES
SEDIMENT
EROSION
Meteorology & Atmospheric Sciences
MD Multidisciplinary
Publication Status
Published