气候变化领域集成服务门户(CCPortal): Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al

CCPortal

DOI	10.1130/B31767.1
	Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al
	Struck M.; Jansen J.D.; Fujioka T.; Codilean A.T.; Fink D.; Egholm D.L.; Fülöp R.-H.; Wilcken K.M.; Kotevski S.
发表日期	2018
ISSN	167606
起始页码	1017
结束页码	1040
卷号	130 期号:2021-05-06
英文摘要	Hillslopes stand at the top of the geomorphic conveyor belt that produces and transports mass throughout landscapes. Quantification of the tempo of hillslope evolution is key to identifying primary sediment production and understanding how surface processes shape topography. We measured cosmogenic 10Be and 26Al on three desert hillslopes in postorogenic central Australia and quantified their soil dynamics and evolution. We found that hillslope morphology is governed by lithological factors, and differing nuclide abundances reflect the main sediment transport processes. Slope wash is widespread, and shrink-swell soil processes drive downslope creep and upward migration of gravels detached from underlying bedrock. We applied Monte Carlo-based inversion modeling to reconstruct soil production and the exhumation histories of stony mantle gravels. Underlying silty soils derive from eolian dust inputs dating to at least 0.2 Ma and possibly more than 1 Ma, in line with intensified aridity. Exposed bedrock erodes at ~0.2-7 m/m.y., and under soil, it erodes at maximum rates of < 0.1 m/m.y. up to 10 m/m.y. Accordingly, particles spend 2-6 m.y. or more in the upper 0.6 m of the bedrock column and an additional ~0.2-2 m.y. or more within hillslope soils. Such long periods near the surface result in surface particles acquiring inherently low 26Al/10Be ratios. Bedrock erodibility underpins regional variations in erosion rate, and the slow tempo of hillslope evolution is largely independent of base level. This suggests a distinctive top-down evolution among postorogenic hillslopes set by authigenic rates of sediment production, rather than by fluvial incision as in tectonically active settings. © 2017 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185036
作者单位	School of Earth and Environmental Sciences, University of Wollongong, Wollongong, 2522, Australia; Department of Geoscience, Aarhus University, Aarhus C, 8000, Denmark; Australian Nuclear Science and Technology Organisation, Lucas Heights, 2234, Australia
推荐引用方式 GB/T 7714	Struck M.,Jansen J.D.,Fujioka T.,et al. Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al[J],2018,130(2021-05-06).
APA	Struck M..,Jansen J.D..,Fujioka T..,Codilean A.T..,Fink D..,...&Kotevski S..(2018).Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al.Bulletin of the Geological Society of America,130(2021-05-06).
MLA	Struck M.,et al."Soil production and transport on postorogenic desert hillslopes quantified with 10Be and 26Al".Bulletin of the Geological Society of America 130.2021-05-06(2018).