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中国沙漠 ›› 2024, Vol. 44 ›› Issue (5): 41-49.DOI: 10.7522/j.issn.1000-694X.2024.00026

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库布齐沙漠南缘沙源限制型抛物线形沙丘沉积构造

马奕鑫(), 武子丰, 王卓然, 韩旭娇, 乌友罕, 哈斯额尔敦()   

  1. 北京师范大学 地理科学学部 自然资源学院,北京 100875
  • 收稿日期:2023-11-07 修回日期:2024-02-04 出版日期:2024-09-20 发布日期:2024-10-15
  • 通讯作者: 哈斯额尔敦
  • 作者简介:哈斯额尔敦(E-mail: hasi@bnu.edu.cn
    马奕鑫(2001—),女,山西运城人,硕士研究生,研究方向为干旱区地貌。E-mail: 202221051173@mail.bnu.edu.cn
  • 基金资助:
    国家重点研发计划课题(2023YFF1305303);国家自然科学基金项目(42271005)

Internal sedimentary structure of source-limited parabolic dune in southern margin of Hobq Desert

Yixin Ma(), Zifeng Wu, Zhuoran Wang, Xujiao Han, Youhan Wu, Hasi Eerdun()   

  1. School of Natural Resources,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China
  • Received:2023-11-07 Revised:2024-02-04 Online:2024-09-20 Published:2024-10-15
  • Contact: Hasi Eerdun

摘要:

沙丘沉积构造常呈现层理,可为研究沙丘形成和演化提供重要信息。选取库布齐沙漠南缘一个相对成熟的抛物线形沙丘,通过遥感动态监测和人工剖面的观察分析,讨论了抛物线形沙丘的动态及沉积构造特征。结果表明:沙丘形态、动态与内部构造之间具有良好一致性。沙丘以内侧侵蚀和外侧植物截留沉积形式向前移动并伴有侧向外扩,沙丘不同单元展现出各自特征的层理类型。受沙源缺失影响,该沙丘弧顶部位的沉积构造主要为粒序交互的平行层理和中-低角度交错层理,丘顶和背风坡层理中夹杂粗砂透镜体;两翼的沉积构造相对一致,主要为平行层理和中-高角度交错层理,内侧下层为倾向向东的前积层,内侧上层为倾向向内的加积层,外侧出现倾向向外的高角度前积层。沙丘的沉积构造特征反映了其主要的沉积过程,该地区抛物线形沙丘的沉积过程为沙波纹沉积与颗粒降落沉积,在两翼外侧伴有重力坍塌形成的颗粒流沉积。由于沙丘表面过程的复杂性,仅依据沙丘层理产状还不能准确判断区域气流方向。

关键词: 抛物线形沙丘, 沉积构造, 动态, 库布齐沙漠

Abstract:

The internal sedimentary structure of sand dunes is often manifested as bedding structures, providing crucial information for the study of dune formation and evolution. This study focuses on a relatively mature parabolic sand dune located on the southern margin of the Hobq Desert. This thesis discusses the dynamics and depositional features of parabolic sand dunes through a combination of remote sensing dynamic monitoring and observational analysis of manually excavated profiles. The results indicate a consistent correlation between the dune morphology, dynamics, and internal structures. The dune undergoes forward movement and lateral expansion in the form of inner-side erosion and outer-side interception by vegetation, and here are variations in the types of bedding in different parts of the dune. Due to the absence of a consistent sand source, the sedimentary structures observed at the nose of the parabolic dune primarily consist of parallel bedding with grain sequence interaction and medium-low dip angle cross-bedding, and coarse sand lenses are present in the bedding of the crest and leeward slope. The sedimentary structures on both arms of the dune are relatively consistent, primarily characterized by parallel bedding and middle-high dip angle cross-bedding. The lower layers of inner slopes exhibit eastward-inclined foreset beds, while the upper layers of inner slopes exhibit inward-inclined climbing beds. On the outer slopes of two arms, there is outward-inclined high dip angle foreset beds. The sedimentary structural features of the sand dune reflect its primary depositional processes. In the southern margin of the Hobq Desert, the deposition processes of parabolic sand dunes involve sand ripple deposition and particle fall deposition. Additionally, on the outer slopes of the two arms, there is particle flow deposition resulting from gravity collapse. Due to the complexity of surface processes, relying solely on dune bedding may not accurately determine regional airflow directions.

Key words: parabolic dunes, sedimentary structure, evolution, Hobq Desert

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