河西走廊西部全新世气候环境变化的元素地球化学记录

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; ~8100-5800 cal BP气候相对湿润, 其中最湿润时段出现在~8100-7200 cal BP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。

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

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-14C 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.