艾比湖周边灌丛沙堆风沙沉积记录的气候环境演化

选择位于西风区的新疆艾比湖周边灌丛沙堆为研究对象,利用光释光测年初步建立风沙沉积的时间序列,分析了风沙沉积粒度和地球化学元素两个环境代用指标的古气候意义,并通过区域对比和综合分析,初步建立区域风沙气候环境演变序列。结果表明:研究区灌丛沙堆主要发育于晚全新世,缺失早中全新世的风沙沉积。晚冰期以来,艾比湖地区的风沙气候环境演变经历了一系列冷湿（凉湿）-暖干（温干）的变化过程,其中暖干（温干）时期气候干旱,风力强劲,湖滨阶地主要发生风蚀过程,不利于灌丛沙堆的发育。晚全新世以来,艾比湖周边灌丛沙堆发育较普遍,风沙沉积至少记录了3次相对干旱期和3次相对湿润期。灌丛沙堆记录的风沙气候环境演化序列与北疆其他全新世沉积记录有较好的一致性,基本遵循晚次冰期以来气候变化的西风模式,同时也受到局地风沙地貌环境的影响。

Record for Climate Revolution in Aeolian Deposit of Nabkhas around the Ebinur Lake

Analysis on nabkhas around the Ebinur Lake which located in northern Xinjiang of westerly zone show that the aeolian deposit of nabkhas was formed in late Holocene and there was a lack of aeolian deposit in early-mid Holocene. Comparative studies also revealed that the climate in the region had experienced a number of warm-dry and cold-wet (cool-wet)changes since the late Holocene. The nabkhas around Ebinur Lake were well-developed and contained 3 dry periods and 3 wet periods at least since the late glacial epoch. The records of climate revolution in the region are in good agreement with the climate revolution from other Holocene records in northern Xinjiang. The change basically follows in the steps of westerly dominated Holocene climatic model, and also is affected by the sandstorm landscape of Ebinur Lake area.