Quaternary dust source variation across the Chinese Loess Plateau
Quaternary dust source variation across the Chinese Loess Plateau
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DOI：
10.1016/j.palaeo.2015.06.024
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发表时间：
2015-10-01
影响因子：
3
通讯作者：
Xu, Zhiwei
中科院分区：
文献类型：
--
作者：
Bird, Anna;Stevens, Thomas;Xu, Zhiwei
中国中北部的黄土高原拥有陆地上最有价值的新生代气候档案之一。确定这一大量风成沉积物档案的来源对于解释黄土气候指标、过去的大气风模式以及过去约2500万年可能存在的气候变化/构造对侵蚀的控制至关重要。尽管具有如此重要的意义，但对于精确的源区以及这些源区随时间和在整个高原上的变化程度，仍存在许多分歧。为了解决这一问题，我们采用了一种多技术方法，将碎屑单颗粒锆石U - Pb定年和重矿物分析相结合，以确定第四纪黄土的来源，并限制它们在黄土高原上的地理变化。我们将我们的数据与来自黄土和可能的源区的合适的已发表单颗粒数据集相结合。结果表明，整个高原的沙尘源在空间上存在显著的异质性。黄土高原西部的地点与黄河和青藏高原北部有很强的亲缘关系，而在更东部，源自华北克拉通的物质的影响变得更加显著（图1）。这种源区的空间变异性意味着与沙尘源的关系比以前设想的要复杂得多。黄土/土壤单元的物源也随时间而变化，尽管这些变化与以前假设的冰期/间冰期的变化之间没有一致的关系。这种变化表明沙尘源和输送模式是高度动态和多变的，受到单个冰期 - 间冰期事件内突然的气候变化以及黄河系统动态的影响。（C）2015爱思唯尔有限公司。保留所有权利。
The Chinese Loess Plateau in north central China contains one of the most valuable Cenozoic climate archives on land. Establishing the origin of this substantial archive of aeolian sediments is critical for the interpretation of loess climate proxies, past atmospheric wind patterns and changing climatic/tectonic controls on erosion over potentially the past 25 Ma. Despite this significance there are a number of disagreements over the precise source areas and the extent to which these vary through time and across the plateau. To address this, we utilize a multi-technique, approach of combined detrital single-grain zircon U-Pb dating and heavy mineral analysis to establish the sources of loess through the Quaternary and constrain their variation geographically across the Loess Plateau. We combine our data with suitable published single-grain datasets from loess and possible source regions. The results demonstrate a dramatic spatial heterogeneity of dust sources across the plateau. Sites to the west of the Loess Plateau show strong affinity to the Yellow River and the northern Tibetan Plateau, while further east the influence of North-China-Craton-derived material becomes more significant (Fig. 1). This spatial variability in source implies a far more complex relationship to dust sources than previously envisioned. The provenance of loess/soil units also varies through time, although there is no consistent relationship between these shifts and changing glacial/interglacial periods, as hypothesized previously. This variation demonstrates highly dynamic and variable dust sources and transport modes that are influenced by abrupt climate shifts within individual glacial-interglacial episodes, and potentially the dynamics of the Yellow River system. (C) 2015 Elsevier B.V. All rights reserved.