河西走廊西部全新世气候环境变化的元素地球化学记录  

Holocene Climate and Environmental Changes Reconstructed from Elemental Geochemistry in the?Western Hexi Corridor

作　　者：李小强[1,2] 刘汉斌[2,3] 赵克良[1] 纪明[4] 周新郢[1] 

机构地区：[1]中国科学院古脊椎动物与古人类研究所,中国科学院脊椎动物演化与人类起源重点实验室,北京100044 [2]中国科学院地球环境研究所,西安710075 [3]中国科学院大学,北京100049 [4]中科院南京地理与湖泊研究所,南京210008

出　　处：《人类学学报》2013年第1期110-120,共11页Acta Anthropologica Sinica

基　　金：国家自然科学基金项目(41001062;41172161;41102113)资助

摘　　要：通过河西走廊西部地区条湖剖面沉积物元素地球化学分析，结合高精度AMS^14C测年，探讨研究区～11400—1060 cal BP期间的气候环境演变过程。研究结果显示～11400～9400 cal BP期间，条湖处于高水位且流域内化学风化作用较强，气候条件相对温暖湿润；～9400—8100 cal BP期间，湖泊水位下降，化学风化作用减弱，指示了干旱的气候条件；～8100—5800calBP气候相对湿润，其中最湿润时段出现在-8100—7200calBP之间；-5800-4800 cal BP期间，气候转干-4800 cal BP以后人类活动增强，导致区域荒漠化加剧。A 210-cm-long laminated sediment core was collected from Tiaohu Lake in the western Hexi Corridor, and used to investigate the climate and environmental changes during -11400-1060 cal BP, based on elemental geochemistry and precise AMS-t4C dating. The level of Tiaohu Lake is high with intensified chemical weathering in the area indicating relatively warm and humid conditions from -11400 to 9400 cal BP. The lake level dropped and the intensity of chemical weathering weakened, suggesting dry conditions between -9400 and 8100 cal BP. During -8100-5800 cal BP, the climate was relatively wet in the study area. One of the most humid periods occurred between 8100-7200 cal BP in the Holocene. The climate became dry in the area between -5800 and 4800 cal BP. After -4800 cal BP, increased human activities resulted in the severity level of desertification in the study area.

关 键 词：河西走廊 条湖 全新世 地球化学元素 RB/SR Fe/Mn 

分 类 号：P532[天文地球—古生物学与地层学]