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中国沙漠 ›› 2022, Vol. 42 ›› Issue (1): 139-146.DOI: 10.7522/j.issn.1000-694X.2021.00140

• • 上一篇    

策勒绿洲近地表大气降尘粒度指示的分选特征及其意义

林永崇1(), 穆桂金2, 陈丽玲1, 吴楚娜1, 徐立帅3,4()   

  1. 1.闽南师范大学 历史地理学院,福建 漳州 363500
    2.中国科学院新疆生态与地理研究所 荒漠与绿洲生态国家重点实验室,新疆 乌鲁木齐 830011
    3.山西农业大学 资源环境学院,山西 太谷 030801
    4.中国气象局乌鲁木齐沙漠气象研究所,新疆 乌鲁木齐 830002
  • 收稿日期:2021-07-19 修回日期:2021-10-09 出版日期:2022-01-20 发布日期:2022-01-28
  • 通讯作者: 徐立帅
  • 作者简介:徐立帅(E-mail: sdytxu@126.com
    林永崇(1983—),男,福建漳州人,博士,副教授,研究方向为环境演变。E-mail: linyongchong@itpcas.ac.cn
  • 基金资助:
    国家自然科学基金青年科学基金项目(41601012);福建省高校杰出青年科研人才培育计划项目;福建省教育厅中青年教师教育科研项目(JAT190365);山西农业大学科技创新基金项目(2016YJ16);中国沙漠气象科学研究基金项目(Sqj2020011)

Sorting characteristics and its implication of the grain size of modern atmospheric dust deposition near the surface of the Cele Oasis Xinjiang China

Yongchong Lin1(), Guijin Mu2, Liling Chen1, Chuna Wu1, Lishuai Xu3,4()   

  1. 1.School of History and Geography,Minnan Normal University,Zhangzhou 363500,Fujiang,China
    2.State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China
    3.College of Resources and Environment,Shanxi Agricultural University,Taigu 030801,Shanxi,China
    4.Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,China
  • Received:2021-07-19 Revised:2021-10-09 Online:2022-01-20 Published:2022-01-28
  • Contact: Lishuai Xu

摘要:

风成沉积一般为多峰态粒度分布,不同峰态往往指示不同的沉积分选作用。这种分选作用形成的粒度特征是否具有稳定性可以通过现代大气降尘观测进一步证实。本研究通过对策勒绿洲两次大气降尘11个位置3 m和0.5 m高度样品粒度特征进行分析,试图揭示风成沉积粒度特征的稳定性。结果表明:两次大气降尘粒级范围都集中在0.4—250 μm,不同高度的大气降尘都显示典型的双峰态粒度分布特征,其中粗粒峰态众数为67—75 μm,细粒峰态众数12—21 μm。粗粒峰态和细粒峰态各自在不同位置和不同高度上都表现出稳定一致的粒度分布特征,这表明大气降尘在近地表空间上经历稳定一致的沉积分选作用。因此,风成沉积粒度特征适合用于指示区域沉积动力环境,多峰态分离分析可能获得更加明确的环境信息。

关键词: 大气降尘, 粒度, 多峰态, 分选作用

Abstract:

Aeolian deposits often exhibit bimodal grain size distribution characteristics, and different sub-peaks indicate different sedimentary sorting processes. It has not been confirmed by modern atmospheric dust fall observations that whether the grain size characteristics, being caused by sedimentary sorting, exhibits stability. This study attempts to reveal the spatial variation characteristics of aeolian deposits by sampling two phases atmospheric dust falls at 11 spots at 3 m and 0.5 m heights and analyzing the grain size characteristics. The results show that in both periods of atmospheric dust fall, the grain size ranges from 0.4 μm to 250 μm at the two heights, and the deposited dusts exhibit typical bimodal grain size distribution characteristics, which with main modal size of 67-75 μm and secondary modal size of 12-21 μm. The coarse-grained peaks (or fine-grained peaks) show consistent grain size distribution characteristics at 11 spots and two heights. This indicates that they experience stable and consistent sedimentary sorting in the near-surface. Therefore, the grain size characteristics of aeolian deposits are suitable for indicating regional sedimentary dynamic environments, and multi-modal separation analysis may indicate environmental information clearer.

Key words: atmospheric dust deposition, grain size, multimodality, sorting

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