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中国沙漠 ›› 1999, Vol. 19 ›› Issue (2): 104-109.

• 论文 • 上一篇    下一篇

晚冰期以来毛乌素沙漠环境特征的湖沼相沉积记录

苏志珠1,3, 董光荣1,2, 李小强2, 陈惠忠1,2   

  1. 1. 中国科学院兰州沙漠研究所, 兰州 730000;
    2. 中国科学院西安黄土与第四纪地质实验室, 西安 710054;
    3. 山西大学黄土高原研究所, 太原 030006
  • 收稿日期:1998-07-24 修回日期:1998-10-22 出版日期:1999-06-20 发布日期:1999-06-20
  • 作者简介:苏志珠(1964-),男,助理研究员。主要从事干旱区地貌与第四纪地质研究。
  • 基金资助:
    中国科学院重大项目(KZ951-A1-402)和国家自然科学基金(49701001)共同资助

The Lake Swamp Sediment Records on the Environmental Characteristics of Mu Us Desert since the Late Glacial Epoch

SU Zhi-zhu1,3, DONG Guang-rong1,2, LI Xiao-qiang2, CHENG Hui-zhong1,2   

  1. 1. Institute of Desert Research, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. National Key Lab of Loess and Quaternary Geology, Chinese Academy of Sciences, Xi'an 710054, China;
    3. Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China
  • Received:1998-07-24 Revised:1998-10-22 Online:1999-06-20 Published:1999-06-20

摘要: 毛乌素沙漠南缘靖边海则滩湖沼相沉积剖面,真实地记录了晚冰期以来东亚季风气候和沙漠演化历史。在地层沉积相划分和测年基础上,据地球化学元素和孢粉等气候指标分析表明,该区古气候变迁序列为:12kaBP前干燥寒冷;12~10kaBP气候转暖湿;10~8.5kaBP以温湿为主,在10~9.5kaBP出现YoungerDryas冷干事件;8.5~3.0kaBP温暖湿润;3.0kaBP后气候趋于半干旱与现代气候较接近。这种气候演化规律是受地球轨道因素影响,通过东亚冬夏季风的强弱变化来实现的。

关键词: 晚冰期, 毛乌素沙漠, 气候变化, Younger Dryas事件

Abstract: The desert loess transitional zone located between the northern part of loess plateau and the southern fringe of Mu Us Desert is very sensitive to the climatic changes. There has received great attention. In this paper, Haizetan profile of Jinbian County (37°42'N,108°48'E) situated in the southern edge of Mu Us Desert, has developed a thick lake swamp sediments, which has completely documented the history of East Asia monsoon and desert evolution since the late glacial epoch. The major climatic variations have been recorded and analyzed based on the sedimental facies, stratigraphic data, geo chemistry, pollen records from lake swamp deposit sequences. Some results are concluded: (1) The climate before 12 ka BP was colder and drier than that in Holocene; Sediments with a thick eolian sand layer indicated intensified winter monsoon and strong wind sand activities. (2) During the period from 12 to 10 ka BP, climatic indicator analysis reflected higher content of Fe 2O 3, Al 2O 3,Co,Ni and lower content of Na 2O,K 2O,Sr,Ba, and high pollen concentration, which suggested that climatic conditions had started to ameliorate and became relatively warm and wet. (3) During the period of 10~8.5 ka B P, the general climate was warmer and wetter, which was resulted from enhanced summer monsoon activity due to the increased summertime solar radiation in Northe rn Hemisphere. During the period the summer monsoon dominated and precipitation, pollen volume increased. Around about 9 ka BP, the pollen volume reached its peak, rainfall was abundant. However, the lowest pollen content between 10 and 9.5 a BP indicated that the climate changed to dry cold dramatically and deposited eolian sand layer. This stage matched the Younger Dryas sub period of North Atlantic Period in Europe. (4) The period between 8.5 and 3.0 ka BP correlated with Megathermal Phase of Holocene. The climate became warmer and wetter resulted from intensified summer monsoon activity. Many researches indicate that during 8.5~3.0 ka BP it was warm and wet in other regions, such as in eastern and northern China. (5) Since 3.0 ka BP, the climate in this area gradually became dry or approx imated to present climatic condition.

Key words: The late glacial epoch, Mu Us Desert, Climatic change, Younger Dryas event

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