Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau

doi:10.1016/j.epsl.2017.03.014

ISL OpenIR > 青海盐湖研究所知识仓储

	Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau
	Li, Le; Liu, Xiangjun; Li, Tao; Li, Laifeng; Zhao, Liang; Ji, Junfeng; Chen, Jun; Li, Gaojun
第一作者	Li, Le
	2017-06
发表期刊	EARTH AND PLANETARY SCIENCE LETTERS
ISSN	0012-821X
卷号	467 页码:64-71
关键词	Surface Process Erosion Dust Storm Paleoclimate Uranium Isotope Dating
摘要	The U-234/U-238 ratio of fine particles can record the time since their separation from bed rock because of the disruption of uranium series equilibrium introduced by the recoil of daughter Th-234 nuclei (precursor of U-234) out of particle surfaces during the decay of U-238. Application of the uranium comminution age method, which has great potential in tracing production and transportation of sediments is however complicated by the weathering dissolution of U-234 depleted particle surfaces, the difficulty in determining the fraction of recoiled nuclei, and the precipitation of exogenetic U-234. Here we minimize these complications by using a newly developed precise size separation using electroformed sieve, and a chemical protocol that involves reductive and oxidative leaching. Eolian deposits collected from the Chinese Loess Plateau (CLP) were used to test the validity of our method. Possible effects of weathering dissolution were also evaluated by comparing samples with different weathering intensities. The results show decreasing U-234/U-238 ratios in fine eolian particles with increasing sedimentation age, agreeing well with the theoretical prediction of the comminution age model. This successful application of the uranium comminution age approach to the eolian deposits on the CLP is also aided by a stable dust source, the low weathering intensity, the lack of consolidation, and the well-defined age model of the deposits. A transportation time of 242 +/- 18 ka was calculated for the eolian deposits, which indicates a long residence time, and thus extensive mixing, of the dust particles in source regions, partly explaining the stable and homogeneous composition of the eolian dust over glacial-interglacial cycles. (C) 2017 Elsevier B.V. All rights reserved.
DOI	10.1016/j.epsl.2017.03.014
语种	英语
引用统计
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/4243
专题	青海盐湖研究所知识仓储盐湖地质与环境实验室
推荐引用方式 GB/T 7714	Li, Le,Liu, Xiangjun,Li, Tao,et al. Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau[J]. EARTH AND PLANETARY SCIENCE LETTERS,2017,467:64-71.
APA	Li, Le.,Liu, Xiangjun.,Li, Tao.,Li, Laifeng.,Zhao, Liang.,...&Li, Gaojun.(2017).Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau.EARTH AND PLANETARY SCIENCE LETTERS,467,64-71.
MLA	Li, Le,et al."Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau".EARTH AND PLANETARY SCIENCE LETTERS 467(2017):64-71.

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