DOI: 10.1038/s41561-020-0611-4
论文题名: Late Cenozoic climate change paces landscape adjustments to Yukon River capture
作者: Bender A.M. ; Lease R.O. ; Corbett L.B. ; Bierman P.R. ; Caffee M.W. ; Rittenour T.M.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2020
卷: 13, 期: 8 起始页码: 571
结束页码: 575
语种: 英语
英文关键词: bedrock
; Cenozoic
; climate change
; climate forcing
; cooling
; glacial-interglacial cycle
; headwater
; landscape change
; luminescence dating
; paleoclimate
; precipitation (climatology)
; reconstruction
; river channel
; runoff
; sedimentation
; Alaska
; Bering Sea
; Fortymile River
; Pacific Ocean
; United States
; Yukon River
英文摘要: Late Cenozoic cooling and changes in glacial–interglacial cycle tempo are thought to increase global rates of erosion starting ~3 million years ago (Ma). Bedrock rivers set rates and patterns of erosion in most landscapes, but constraints on river response to late Cenozoic climate change remain elusive. Here, we determine cosmogenic isotope and luminescence ages of well-preserved bedrock terraces along the Fortymile River (Yukon River basin) to reconstruct an ~5 Myr history of fluvial adjustment to late Cenozoic climate and Yukon River headwater capture at 2.6 Ma. Post-capture Yukon River downcutting lowered the Fortymile River outlet, forcing subsequent bedrock incision throughout the Fortymile basin in two pulses, from 2.4 to 1.8 Ma and at ~1 Ma. These pulses of incision disrupted longer intervals of slow river channel sedimentation under near-consistent climate forcing from 4.8 to 2.4 Ma and from 1.8 to ~1 Ma. The Fortymile River delivers sediment to the Bering Sea, where provenance and accumulation rate changes since 4.3 Ma match observed variations in incision. Our results link alluviation and incision to late Cenozoic climate steadiness and change, respectively, and support the hypothesis that climate-forced changes in precipitation and runoff fundamentally control the pace of river incision and landscape erosion. © 2020, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169555
Appears in Collections: 气候变化与战略
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作者单位: US Geological Survey, Alaska Science Center, Anchorage, AK, United States; Department of Geology, University of Vermont, Burlington, VT, United States; Department of Physics and Astronomy and Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IL, United States; Department of Geosciences and USU Luminescence Lab, Utah State University, Logan, UT, United States
Recommended Citation:
Bender A.M.,Lease R.O.,Corbett L.B.,et al. Late Cenozoic climate change paces landscape adjustments to Yukon River capture[J]. Nature Geoscience,2020-01-01,13(8)