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中国沙漠 ›› 2025, Vol. 45 ›› Issue (1): 75-84.DOI: 10.7522/j.issn.1000-694X.2024.00150

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河西走廊流水型遗迹沙丘的辨识特征与形成模式

隋文舒(), 陈颢, 肖锋军(), 胡光印, 董治宝   

  1. 陕西师范大学 地理科学与旅游学院,陕西 西安 710119
  • 收稿日期:2024-09-24 修回日期:2024-11-05 出版日期:2025-01-20 发布日期:2025-01-13
  • 通讯作者: 肖锋军
  • 作者简介:肖锋军(E-mail: xiaofengjun@snnu.edu.cn
    隋文舒(1999—),女,山东潍坊人,硕士研究生,主要从事风沙地貌研究。E-mail: suiwenshu@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)

Identification characteristics and formation model of fluvial ghost dunes in Hexi Corridor

Wenshu Sui(), Hao Chen, Fengjun Xiao(), Guangyin Hu, Zhibao Dong   

  1. School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China
  • Received:2024-09-24 Revised:2024-11-05 Online:2025-01-20 Published:2025-01-13
  • Contact: Fengjun Xiao

摘要:

遗迹沙丘是不同于传统堆积型沙丘的风沙地貌,属侵蚀型沙丘,为负地形地貌。以河西走廊嘉峪关市北部的流水型遗迹沙丘为研究对象,通过对比卫星影像,结合野外剖面数据,验证和探讨了其形态特征、形成模式、与熔岩流型遗迹沙丘的差异及其环境意义。结果表明:(1)流水型遗迹沙丘主要分布在河道出山口附近,多呈现以近似相互平行的弧线按不同间距排列的分布格局,弧线长短不一,部分被沙丘掩埋而间断,与新月形沙丘背风坡基部轮廓相似。(2)流水型遗迹沙丘剖面可划分为3层:以粉沙黏土构成的黏土层(有泥裂),以细沙和极细沙为主的过渡层,以及以细沙为主的风成层。形态、剖面及影像中沙丘背风坡的积水现象都表明该地貌是由流水携带泥沙物质掩埋沙丘背风坡而成。(3)地形、沙丘走向和暂时性河流走向的合理关系是形成流水型遗迹沙丘的关键因素,当新月形沙丘背风坡面向流水方向时更易形成。(4)流水型遗迹沙丘与熔岩流型遗迹沙丘相比,因流水密度小、黏度小且流动性强,通常形成以弧线形态存在的不完整型遗迹沙丘,且易被风蚀;而后者反之。同时流水比熔岩流多发,会形成多期遗迹沙丘。

关键词: 流水型遗迹沙丘, 河西走廊, 形态特征, 形成模式

Abstract:

Ghost dune is a kind of aeolian sand landform which is different from the traditional cumulated dune. It belongs to eroded dune and is a negative landform. This paper takes the fluvial ghost dune in the north of Jiayuguan City in Hexi Corridor as the research object. By comparing satellite images and field sedimentary profile data, this paper verifies and discusses its morphological characteristics, formation model, differences from the lava flow ghost dune and its environmental significance. The results show that: (1) The fluvial ghost dunes are mainly distributed near the mountain pass of the river channel, and most of them present a distribution pattern of approximately parallel arcs arranged at different intervals. The arcs have different lengths, and some of them are buried by the dunes and discontinuous, which is similar to the base of the lee slope of the barchan dune. (2) The fluvial ghost dune sedimentary profile can be divided into three layers: the clay layer composed of silty clay (with mud cracks), the transition layer dominated by fine sand and extremely fine sand, and the eolian layer dominated by fine sand. The form, sedimentary profile and water accumulation on the leeward slope of the dune in the image all indicate that the fluvial ghost dune is formed by the fluvial water carrying sediment and burying the leeward slope of the dune. (3) The reasonable relationship between topography, dune direction and temporary river direction is the key factor for the formation of fluvial ghost dune, which is easier to form when the lee slope of barchan dune faces the direction of water flow. (4) Compared with lava flow ghost dunes, due to the low density, low viscosity and strong fluidity of the fluvial medium, it usually forms an incomplete ghost dune with a curved shape and is easy to be eroded by wind and vice versa. There are also more water flows than lava flows, which can form multi-stage fluvial ghost dunes.

Key words: fluvial ghost dune, Hexi Corridor, morphological characteristics, formation model

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