地理学报 ›› 2019, Vol. 74 ›› Issue (11): 2385-2400.doi: 10.11821/dlxb201911014

• 气候变化与生态环境 • 上一篇    下一篇

MIS 3以来雅鲁藏布江流域风成沉积及环境意义

凌智永1,2,3,靳建辉4,吴铎1,刘向军2,3,夏敦胜1,陈发虎1,5,6   

  1. 1. 兰州大学资源环境学院 西部环境教育部重点实验室,兰州 730000
    2. 中国科学院青海盐湖研究所 盐湖资源综合高效利用重点实验室,西宁 810008
    3. 青海省盐湖地质与环境重点实验室,西宁 810008
    4. 福建师范大学地理科学学院,福州 350007
    5. 中国科学院青藏高原研究所 高寒生态与生物多样性重点实验室,北京 100101
    6. 中国科学院青藏高原地球科学卓越创新中心,北京 100101
  • 收稿日期:2018-10-15 修回日期:2019-07-01 出版日期:2019-11-25 发布日期:2019-11-01
  • 作者简介:凌智永(1983-), 男, 河南商丘人, 博士, 助理研究员, 主要从事干旱环境与气候变化研究。E-mail: lingzhiyong@foxmail.com
  • 基金资助:
    国家自然科学基金项目(41501001);国家自然科学基金项目(41790421);国家重点研发计划(2018YFC0406605)

Aeolian sediments and their paleoenvironmental implication in the Yarlung Zangbo catchment (southern Tibet, China) since MIS3

LING Zhiyong1,2,3,JIN Jianhui4,WU Duo1,LIU Xiangjun2,3,XIA Dunsheng1,CHEN Fahu1,5,6   

  1. 1. Key Laboratory of West China's Environmental System, Ministry of Education, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
    2. Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, CAS, Xining 810008, China
    3. Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lake, Xining 810008, China
    4. College of Geosciences, Fujian Normal University, Fuzhou 350007, China
    5. Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China
    6. CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
  • Received:2018-10-15 Revised:2019-07-01 Online:2019-11-25 Published:2019-11-01
  • Supported by:
    National Natural Science Foundation of China(41501001);National Natural Science Foundation of China(41790421);National Key R&D Program of China(2018YFC0406605)

摘要:

雅江流域风成沉积广泛发育,其气候指示意义及年代的界定尚不够清晰。从雅江全流域视角出发,全面分析了不同区域风成沉积的发育机制及模式,同时对风成沉积年代数据归一化处理,并与全球气候对比研究。结果表明:① 流域内风成沉积有盛行风场发育模式和局地风场发育模式,不同模式对环境的指示意义不同。② 雅江流域风成沉积多堆积于末次盛冰期(LGM)以后,且主要发育于晚冰期(15 ka BP)以来的不同时段,冰川退缩地表裸露,丰富的冲洪积碎屑物源可能是风成沉积发育的主控因素;更早时段的风成沉积因LGM后气候转暖、冰川消融所致的侵蚀搬运作用而未能保存。③ LGM以来风成沉积过程受区域及全球古气候环境共同控制,波动变化剧烈;其对30°N夏季太阳辐射、印度季风及西风变化信号的指示有所差异,但对YD等全球气候冷事件有较好记录,其沉积过程与高原面上其他区域既存在对全球古气候响应的同步性,又有其区域独特性。④ 流域内风成沉积的强烈堆积过程与全球气候变化并非简单对应关系,呈现出较复杂的响应模式。说明高山河谷环境的风成沉积除受大区域气候影响,还受许多局地环境因素控制,古气候环境的指示意义复杂。

关键词: 风成沉积, 年代, 古气候环境, 雅鲁藏布江, MIS3

Abstract:

The aeolian deposits in the Yarlung Zangbo catchment are widely developed, and its sedimentary development model is complex. The climatic implication and chronological boundary of the aeolian sediments are not clear enough. Therefore, from the perspective of the whole basin, this paper comprehensively analyzed the development mechanism and mode of the aeolian sediments in different regions. At the same time, the chronological data of aeolian deposition is normalized and compared with the classical curve of global climate. The results show that: (1) The aeolian deposits in the basin have prevailing wind field development patterns and local wind field development patterns, and different patterns of aeolian sediments have different indications for the environment. (2) The aeolian sediments in the basin are mostly deposited in the Last Glacial Maximum (LGM), which mainly developed in different periods since the Late Glacial Period (15 ka BP), and the rich source of alluvial debris may be the main controlling factor of the aeolian activities. The aeolian sediments forming in the earlier time were brought into the river and failed to be preserved due to the warming climate and the erosion transport caused by glacial ablation after the LGM. (3) Since the LGM, the aeolian deposition process of Yarlung Zangbo has been controlled by the regional and global paleoclimate environment, and the fluctuations are drastic. The aeolian sedimentary process of different climate stage have different records to the 30°N summer insolation, the Indian monsoon and westerly winds change signal, but have a better response to the Younger Dryas (YD), global cold event. In short, the sedimentary process of Yarlung Zangbo is similar with that of the other regions on the Tibetan Plateau, and both recorded the global paleoclimatic change, but have its regional uniqueness. 4) The strong accumulation process of aeolian sediments in the Yarlung Zangbo catchment is not a simple correspondence with the global classical climate curve, and it presents a more complex response pattern to global climate change, which shows that the aeolian deposition process of the alpine valley environment is not only affected by the climate of the large area, but also controlled by many local environmental factors. Their relation with the paleoclimatic environment is complex.

Key words: aeolian sediments, chronology, paleoclimate and paleoenvironment, Yarlung Zangbo catchment, MIS3