地理学报 ›› 2009, Vol. 64 ›› Issue (3): 339-348.doi: 10.11821/xb200903009

• 地貌演变 • 上一篇    下一篇

乌兰布和沙漠腹地古湖存在的沙嘴证据及环境意义

春喜1,2, 陈发虎3, 范育新3, 夏敦胜4, 赵晖4   

  1. 1. 内蒙古师范大学地理科学学院,呼和浩特010022;
    2. 内蒙古自治区遥感与地理信息系统重点实验室,呼和浩特010022;
    3. 兰州大学西部环境教育部重点实验室,兰州730000;
    4. 中国科学院寒区旱区环境与工程研究所,兰州730000
  • 收稿日期:2008-10-10 修回日期:2008-12-12 出版日期:2009-03-25 发布日期:2010-08-03
  • 作者简介:春喜(1965-),男,博士,内蒙古兴安盟人,主要从事干旱区环境变化研究。E-mail: chunxi@imnu.edu.cn
  • 基金资助:

    国家自然科学基金(40761028)和中国科学技术部国际合作项目(2002CB714004) 联合资助

Evidence of Palaeolake Existence in Ulan Buh Desert and Its Environmental Evolution

CHUN Xi1,2, CHEN Fahu3, FAN Yuxin3, XIA Dunsheng4, ZHAO Hui4   

  1. 1. College of Geographic Science,Inner Mongolia Normal University,Hohhot 010022,China;
    2. Inner Mongolia Key Laboratory of Remote Sensing and Geography Information System,Hohhot 010022,China;
    3. National Laboratory of Western China's Environmental Systems,Lanzhou University,Lanzhou 730000,China;
    4. Key Laboratory of Desert and Desertification,Cold and Arid Regions Environmental and Engineering Research Institute, CAS,Lanzhou 730000,China
  • Received:2008-10-10 Revised:2008-12-12 Online:2009-03-25 Published:2010-08-03
  • Supported by:

    National Natural Science Foundation of China,No.40761028;International Cooperative Project of Ministry of Science and Technology of China,No.2002CB714004.

摘要:

通过大范围的系统野外考察发现, 在乌兰布和沙漠腹地存在众多干盐湖, 其周围存在 不同高度的湖岸堤。其中, 贺日木西尼沙嘴最为典型。该沙嘴呈NW-SE 走向, 海拔高度从1052 m 下降至1035 m, 长达11 km, 是古湖泊发育和存在的重要证据和标志。通过对湖滨沉 积物的OSL 年代测定, 该沙嘴形成于全新世的8.6-7 ka BP 阶段, 与中国西部许多沙漠出现 的相对湿润环境状况相一致。其主要由强劲的风力作用和吉兰泰古湖沿岸流以及丰富的松散 物质传输堆积而成。依据该沙嘴的海拔高程和形成年代来推测, 在乌兰布和沙漠腹地曾经发育面积巨大的古湖, 其范围西到吉兰泰盆地, 东延河套盆地西部, 形成早全新世的吉兰泰古 湖。之后, 受区域构造运动和干旱气候的影响, 古湖水位下降, 水域面积缩小, 古大湖解体, 导致该沙漠腹地的古湖部分水体逐渐向西退缩, 形成了吉兰泰盐湖。在古湖退缩过程中, 乌兰布和沙漠腹地残留众多湖泊, 随着气候干旱化和蒸发作用的加剧, 这些湖泊逐渐演变成盐湖。在强劲的风力驱动下, 古湖周围的松散物质被侵蚀、搬运、扩散、堆积成现在的乌兰布和沙漠。

关键词: 乌兰布和沙漠, 沙嘴, 环境变化

Abstract:

There are numerous dry salt lakes in the hinterland of the Ulan Buh Desert and around them are lakeshore terraces at different heights. The Herom Xil spit discovered in extensive field investigation is the most typical among them. The spit falls from northwest to southeast with elevations ranging between 1052-1035 m a.s.l. and has a length of 11 km. This is an important evidence for the existence and development of the palaeolake. The spit was formed during the period 8.6-7 ka B.P. in early Holocene, based on the OSL dating on beach sediment. The period was coincident with the moist environment observed in many deserts of western China. The strong palaeowind, rich lake sediment sources and currents of Jarantai and Hetao palaeolakes led to the formation of the spit. According to the elevation of the spit, we estimated that in the Ulan Buh Desert hinterland developed a relatively large palaeolake which extended to Jarantai basin westward and to Hetao basin eastward, and thus formed Jarantai megalake in Holocene. With the intensification of dry climate, the palaeolake level declined and the area shrank. Furthermore, numerous lakes remained and evolved into salt lakes in the hinterland of the Ulan Buh Desert. The sands around the palaeolake might have resulted in the formation of the present Ulan Buh Desert.

Key words: Ulan Buh Desert, Herom Xil spit, environmental change