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中国沙漠 ›› 2026, Vol. 46 ›› Issue (2): 358-370.DOI: 10.7522/j.issn.1000-694X.2025.00194

• • 上一篇    

乌兰布和沙漠沉积物粒度和地球化学元素特征及其环境意义

王军广1,2(), 董治宝1(), 刘荣亮1, 史际桥1   

  1. 1.陕西师范大学 地理科学与旅游学院,陕西 西安 710119
    2.海南师范大学 地理与环境科学学院,海南 海口 571158
  • 收稿日期:2025-06-02 修回日期:2025-07-09 出版日期:2026-03-20 发布日期:2026-04-13
  • 通讯作者: 董治宝
  • 作者简介:王军广(1984—),男,河北邯郸人,博士研究生,主要从事风沙地貌学方面研究。E-mail: wjunguang123@snnu.edu.cn
  • 基金资助:
    国家自然科学基金项目(42241110);科技部科技基础资源调查专项(2022FY202304);陕西省2021年自然科学基础研究计划(定向委托)项目(2021JCW-17);中央高校基础业务经费项目(GK202306002);中央高校基础业务经费项目(GK202309006)

Characterization of the grain size and geochemical elements of Ulan Buh Desert sediments and their environmental significance

Junguang Wang1,2(), Zhibao Dong1(), Rongliang Liu1, Jiqiao Shi1   

  1. 1.School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China
    2.College of Geography and Environmental Science,Hainan Normal University,Haikou 571158,China
  • Received:2025-06-02 Revised:2025-07-09 Online:2026-03-20 Published:2026-04-13
  • Contact: Zhibao Dong

摘要:

乌兰布和沙漠是中国北方沙尘和黄河泥沙的主要源区,但与其他沙漠相比,对乌兰布和沙漠沉积物的系统研究有限,尤其对沉积物的粒度特征、元素组成特征等方面尚不明确。本研究分析乌兰布和沙漠沉积物(表层和下层)的粒度特征,并对沉积物的元素组成特征和化学风化程度进行分析。结果表明:乌兰布和沙漠表层和下层沉积物均以细沙和中沙为主,表层沉积物粒径比下层粗,平均粒径2.18 Φ,与国内其他沙漠相比粒度偏粗,分选性较好。乌兰布和沙漠表层和下层沉积物粒度特征表现出相似的分布模式,表明表层和下层沉积物在形成机制上差异不大。乌兰布和沙漠沉积物常量元素以SiO₂和Al₂O₃为主,微量元素以Ba、Sr、Zr、Rb、Co为主,说明沉积物地球化学元素除受元素本身特性外,区域气候环境和新鲜物质补给情况也是影响其化学行为和含量差异的重要影响因素。化学风化指标CIA、A-CN-K和A-CNK-FM三角图解表明乌兰布和沙漠沉积物沙粒沉积环境为寒冷干燥的气候条件,风化程度低,风化作用处于斜长石化学风化的初级阶段。此项研究为深入系统开展乌兰布和沙漠沉积物特征研究和区域生态治理提供理论依据。

关键词: 粒度特征, 元素组成, 风化指数, 沉积环境, 乌兰布和沙漠

Abstract:

The Ulan Buh Desert is a key source of aeolian sand and fluvial sediments delivered to the Yellow River in northern China. However, systematic studies on its sedimentological and geochemical characteristics remain limited compared to other Chinese deserts, particularly regarding grain-size distribution and elemental composition. Here, we present a comprehensive analysis of sediment grain size, elemental geochemistry, and chemical weathering intensity in both surface and subsurface layers of the Ulan Buh Desert. Our results demonstrate that sediments are predominantly composed of fine to medium sand, with surface materials (mean grain size: 2.18 Φ) being coarser and better sorted than subsurface layers. This grain-size pattern is notably coarser than those of other Chinese deserts. The consistent grain-size distributions between surface and subsurface sediments suggest similar depositional mechanisms. Geochemically, the sediments are dominated by SiO₂ and Al₂O₃ among major elements, with Ba, Sr, Zr, Rb, and Co as characteristic trace elements. These compositional features reflect not only inherent source rock properties but also regional climatic controls and the input of fresh erosional materials. Chemical weathering indices (CIA, A-CN-K, and A-CNK-FM ternary diagrams) collectively indicate a cold, arid depositional environment with minimal chemical alteration, consistent with early-stage plagioclase weathering. This study establishes a theoretical framework for further investigations into sediment dynamics and geochemical processes in the Ulan Buh Desert, with implications for regional ecological management strategies.

Key words: grain size characteristics, elemental composition, weathering index, sedimentary environment, Ulan Buh Desert

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