通过分析苏干湖地区降尘(含尘暴样品)、湖泊表层沉积(碎屑沉积)以及湖泊东部地表沉积3组样品的元素组成特征发现:3组样品具有同源性,Al和Ti在粉尘释放—沉积中行为稳定,Fe可能受元素分馏效应的影响,在湖泊沉积中富集程度相对较高。6次典型尘暴特征分析结果表明,尘暴降尘中Al、Fe、Ti通量的变化与尘暴发生期间10 min平均风速及其变差系数(Cv)间存在显著的相关关系。Al、Fe、Ti通量不仅可以作为尘暴中风速变化的替代指标,而且可以指示尘暴事件中风速的变化幅度。苏干湖现代沉积(岩心)中Al、Fe、Ti通量变化与冷湖气象站44年的年均大风日数记录具有较好的一致性。因此,可以利用湖泊现代沉积中风成输入碎屑组分(去除有机质和碳酸盐)的Al、Fe、Ti通量作为大风尘暴事件的替代指标,以重建地质历史时期柴达木盆地粉尘源区尘暴演化序列或者粉尘释放历史。
As a hydrologically closed lake,Lake Sugan located at the northern margin of the Qaidam Basin would be employed to study dust storm history in the northeastern Qinghai-Tibetan Plateau.The elemental compositions were analyzed for three types of samples,namely,lake surface deposits,settled sand and dust and the surface sediments from the eastern catchment,respectively.The results indicate that different samples derive from a homologous source.Al and Ti exhibit a stable gain-loss pattern during the period of t...