干旱区生态环境知识资源中心(Arid): A global rate of denudation from cosmogenic nuclides in the Earth's largest rivers

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DOI	10.1016/j.earscirev.2020.103147
	A global rate of denudation from cosmogenic nuclides in the Earth's largest rivers
	Wittmann, H.1; Oelze, M.1; Gaillardet, J.2; Garzanti, E.3; von Blanckenburg, F.1,4
通讯作者	Wittmann, H.
来源期刊	EARTH-SCIENCE REVIEWS
ISSN	0012-8252
EISSN	1872-6828
出版年	2020
卷号	204
英文摘要	Cosmogenic nuclide analysis in sediment from the Earth's largest rivers yields mean denudation rates of the sediment-producing areas that average out the local variations commonly found in small rivers. Using this approach, we measured in situ cosmogenic Al-26 and Be-10 in sand of >50 large rivers over a range of climatic and tectonic regimes covering 32% of the Earth's terrestrial surface. In 35% of the analyzed rivers, we find Al-26/Be-10 ratios significantly lower than these nuclides ' surface-production-rate ratio of 6.75 in quartz, indicating radioactive decay over periods exceeding 0.5 Myr. We invoke a combination of slow erosion, shielding in the source area, and sediment storage and burial during long-distance transport to explain these low ratios. In the other 65% of studied rivers we find 26Al/10Be ratios within uncertainty of their surface production-rate ratio, indicating cosmogenic steady state. For these rivers, we obtain a global source area denudation rate of 141 t/km(2)xyr (54 mm/kyr of rock-equivalent) that translates to a flux of 3.07 +/- 0.56 Gt/yr. By assuming that this sub-dataset is representative of the global land surface, we upscale this value to the total surface area for exorheic basins, thereby obtaining a global denudation flux of 15.2 +/- 2.8 Gt/yr that integrates over the past 11 kyr. This value is slightly lower than published values from cosmogenic nuclides from small river basins (23 (+53/-16)) Gt/yr) upscaled using a global slope model, and also lower than modern sediment and dissolved loads exported to the oceans (24.0 Gt/yr). Our new approach confirms an estimate of global dissolved and solid matter transfer that converges to an encouragingly narrow range of within 35%; whereas the use of paired nuclides in large rivers provides estimates of the buffering timescales of sediment transport.
类型	Review
语种	英语
国家	Germany ; France ; Italy
收录类别	SCI-E
WOS记录号	WOS:000543367100003
WOS关键词	EROSION RATES ; MOUNTAIN EROSION ; SEDIMENT PRODUCTION ; YELLOW-RIVER ; HALF-LIFE ; BE-10 ; AL-26 ; BASIN ; LANDSCAPE ; DESERT
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/319486
作者单位	1.GFZ German Res Ctr Geosci, Potsdam, Germany; 2.Inst Phys Globe, Paris, France; 3.Univ Milano Bicocca, Dept Earth & Environm Sci, Milan, Italy; 4.Free Univ Berlin, Inst Geol Sci, Berlin, Germany
推荐引用方式 GB/T 7714	Wittmann, H.,Oelze, M.,Gaillardet, J.,et al. A global rate of denudation from cosmogenic nuclides in the Earth's largest rivers[J],2020,204.
APA	Wittmann, H.,Oelze, M.,Gaillardet, J.,Garzanti, E.,&von Blanckenburg, F..(2020).A global rate of denudation from cosmogenic nuclides in the Earth's largest rivers.EARTH-SCIENCE REVIEWS,204.
MLA	Wittmann, H.,et al."A global rate of denudation from cosmogenic nuclides in the Earth's largest rivers".EARTH-SCIENCE REVIEWS 204(2020).