内蒙古查干淖尔湖2000a以来气候环境演变的沉积记录  

Sedimentary record of environmental evolution since ca 2000 calyr B P ago in Qehan Lake, Inner Mongolia

作　　者：江南[1] 王永[1] 董进[1] 杨劲松[2] 田飞[1] 刘瑾[1] 汤文坤 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质科学院水文地质环境地质研究所,河北石家庄050061

出　　处：《地质通报》2016年第6期953-962,共10页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:12120113005600;1212011120142)

摘　　要：以内蒙古东部查干淖尔湖西湖深97cm的浅井剖面为对象,根据取得的7个AMS14C测年数据建立其2070cal a BP以来的年代序列,结合孢粉组合特征与粒度组成的综合分析,重建该地区2070cal a BP以来气候环境变化过程。研究结果表明,查干淖尔湖2070cal a BP以来气候环境变化具体可以分为3个阶段：2070~1150cal a BP,孢粉总浓度较高,以蒿属、藜科为主,沉积物各粒级组分变幅较小且以粉砂为主,水动力条件较弱,湖水位较高,气候温凉偏湿;1150~825cal a BP,孢粉总浓度显著降低,耐旱的麻黄属达到最高值,沉积物粗颗粒含量显著增加,水动力条件增强,湖水位降低,气候冷干,其中940~870cal a BP期间气候极端干旱;825cal a BP以来,总体温暖偏湿,有冷干事件发生。太阳活动可能是导致查干淖尔湖过去2000a气候变化的主要驱动力。A 97cm long lacustrine section from Qehan Lake, situated in eastern Inner Mongolia, was used to reestablish the environment and climate changes since the last 2070cal a BP. The chronological framework was built on seven AMS14C ages. On the basis of pollen-spore characteristics and grain size distribution, three environmental stages can be recognized. From 2070~1150cal a BP, this interval was featured by high total pollen concentration, with the dominance of Artemisia and Chenopodiaceae;lacustrine sediments were mainly composed of silt and each fraction presented quite low amplitudes of increases, indicating the weak hydrological conditions and high lake level;this period was characterized by a warm, cool and slightly humid climate. During the period of 1150~825cal a BP, the total pollen concentration significantly decreased and the pollen percentages of xerophyte, especially Ephedra, reached the maximum;the coarse particle content showed obviously increase, sugge sting strong hydrodynamic conditions and low lake level;so in this period, the climate was cold and dry,especially from 940cal a BP to 870cal a BP. Since 825cal a BP, the climate mainly tended to become warm and slightly humid with the occurrence of cold and dry oscillations. Solar activities might have been the dominant force that drove the climate changes in Qehan Lake area since 2000 years ago.

关 键 词：2000a 孢粉 粒度 气候变化 查干淖尔 内蒙古 

分 类 号：X141[环境科学与工程—环境科学]