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中国沙漠 ›› 2026, Vol. 46 ›› Issue (2): 122-130.DOI: 10.7522/j.issn.1000-694X.2025.00117

• • 上一篇    

柴达木盆地柽柳( Tamarix chinensis )灌丛沙堆的光释光年代记录

曾泳昕1(), 鄂崇毅1,2(), 史运坤1, 孙永娟1,2, 汪家伟1, 张兆康1   

  1. 1.青海师范大学 青藏高原地表过程与生态保育教育部重点实验室/青海省自然地理与环境过程重点实验室,青海 西宁 810008
    2.高原科学与可持续发展研究院,青海 西宁 810008
  • 收稿日期:2025-02-21 修回日期:2025-05-14 出版日期:2026-03-20 发布日期:2026-04-13
  • 通讯作者: 鄂崇毅
  • 作者简介:曾泳昕(1997—),女,青海西宁人,博士研究生,主要从事自然地理学研究。E-mail: zyx17745475617@163.com
  • 基金资助:
    国家自然科学基金项目(42171011);青海省自然科学基金项目(2026-ZJ-913M)

Luminescence chronology record of Tamarix chinensis nebkhas in the Qaidam Basin

Yongxin Zeng1(), Chongyi E1,2(), Yunkun Shi1, Yongjuan Sun1,2, Jiawei Wang1, Zhaokang Zhang1   

  1. 1.Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education) / Key Laboratory of Physical Geography and Environmental Process,Qinghai Normal University,Xining 810008,China
    2.Academy of Plateau Science and Sustainability,People's Government of Qinghai Province and Beijing Normal University,Xining 810008,China
  • Received:2025-02-21 Revised:2025-05-14 Online:2026-03-20 Published:2026-04-13
  • Contact: Chongyi E

摘要:

灌丛沙堆是干旱区重要的生物风积地貌,在维持荒漠生态系统结构和生态系统服务功能中发挥着重要的作用,对区域环境变化响应敏感。青藏高原东北部的柴达木盆地是气候变化响应敏感区,其南部洪积扇上柽柳(Tamarix chinensis)灌丛沙堆广泛发育。目前,柴达木盆地柽柳灌丛沙堆的形成年代及气候背景尚不明晰。本研究在该地区选择了7个代表性剖面,共采集14个光释光(OSL)样品进行粗颗粒(63~90 μm)石英、钾长石测年,结果表明:OSL测年法分析石英自然释光信号强度很低,无法构建生长曲线,而钾长石pIR50IR170法能够比较准确地获得该地区柽柳灌丛沙堆的沉积年龄,与同一地层柽柳残枝AMS14C年代结果基本一致。结合前人研究结果,大格勒地区柽柳灌丛沙堆底部OSL年代指示的灌丛沙堆形成时期距今800~400 a,主要在13—15世纪及16—17世纪。柽柳灌丛沙堆的形成、发展时期与柴达木区域强沙尘暴时期同步,且主要形成于寒冷时期,但对区域降水变化的响应并不显著。

关键词: 柴达木盆地, 柽柳(Tamarix chinensis)灌丛沙堆, OSL 年代, AMS14C测年, 风沙活动

Abstract:

Nebkhas are crucial biological aeolian landforms in arid regions, playing a vital role in maintaining the structure of desert ecosystems and their ecosystem services. They are highly sensitive to regional environmental changes. The Qaidam Basin is located in the northeastern part of the Qinghai-Tibetan Plateau, where the present climatic systems are principally regulated by the Asian monsoon and westerlies circulations, respectively. Tamarix chinensis nebkhas are widely distributed in the southern floodplain fan. However, the formation age and climatic background of Tamarix chinensis nebkhas in the Qaidam Basin are not clear. In this study, seven representative profiles are selected in this region, and a total of 14 OSL samples are analyzed using optically stimulated luminescence (OSL) dating. Quartz and K-feldspar fractions of 63-90 μm were extracted, and because the intensity of the luminescence signal of quartz in the samples was too low to be detected, the K-feldspar pIR50IR170 method was chosen for systematic OSL dating. The study shows that K-feldspar particles with a grain size of 63-90 μm can be used to determine the depositional age of the Tamarix chinensis nebkha in this area more accurately by the pIR50IR170 method, and the age of the AMS14C samples obtained from the same location can also be matched. Combining the results of this study with those of previous researchers on the bottom of Tamarix chinensis nebkhas in the Dagele area, we found that the initial period of their formation was around 800 to 400 years before present, and they were mainly concentrated in the phases of 1220-1380 A.D. and 1470-1580 A.D. Comparing and analyzing the results with those from regional aeolian activity and climatic records, we determined that the formation and development of the Tamarix chinensis nebkhas were synchronized with the period of regional strong sandstorms and dust storms. Synchronized with periods of strong regional dust storms and sandstorms, they formed primarily during cold periods and did not respond significantly to changes in regional precipitation. Therefore, we believe that OSL dating of the nebkhas provides a reliable chronological framework for reconstructing the historical aeolian activity in the region. In addition, due to the complex mechanism of the formation and evolution of nebkhas, the response mechanism of the formation and evolution of nebkhas to the regional climate still needs to be further investigated.

Key words: Qaidam Basin, Tamarix chinensis nebkhas, optically stimulated luminescence (OSL) dating, AMS14C, aeolian activity

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