关键词: 河西走廊; 条湖; 全新世; 地球化学元素; Rb/Sr; Fe/Mn

Abstract: 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.

Key words: Hexi Corridor; Tiaohu; Holocene; Elemental geochemistry; Rb/Sr; Fe/Mn