西风区湖泊沉积物中砷元素对气候环境变化的响应研究——以新疆巴里坤湖为例

巴里坤湖是我国西风区古气候环境演变研究的理想区域.根据BLK-1剖面多指标建立了巴里坤湖9 000 cal a BP以来的时间序列,了解其气候演变的过程.结合巴里坤湖古气候演变及砷元素含量的波动变化,发现砷元素变化响应气候环境的演变:气候冷干时期,砷含量较多;而暖湿时期则相对少.此外,砷含量的变化很好地指示了全新世的气候突变事件.巴里坤湖沉积物中砷元素主要来源于湖泊周边基岩受物理风化产生的碎屑,并经由风力带入湖中沉积.干旱的气候环境下,砷的沉积速率较湿润期变化明显.研究结果表明,砷对于我国西风区的古气候环境演变及气候突变事件具有指示作用;砷沉积速率的突变表明在干旱气候环境条件下,砷可能比其他元素更为敏感.不同气候环境下砷元素的来源及波动,也为砷污染的防治提供参考.

Climate Evolution Response to Arsenic Component from Lacustrine Sediments in Westerly Region: A Case Study of Barkol Lake,Xinjiang

Located in the westerly region，Lake Barkol is the ideal research area of the paleoclimate and environment evolution. Based on the multi-proxy analysis of BLK-1 profile, the climate and environmental changes over the past 9000 is established. Arsenic is a poisonous element in nature, which comes mainly from the surrounding bedrock and is brought into the lake by wind after the physical weathering. The research has shown that higher Arsenic values could reflect relatively cold and arid conditions, vice versa. Moreover, arsenic is also a good indicator of the abrupt climate events in Barkol lake during the Holocene. Arsenic is so sensitive that its deposition rate is similar with other elements in the wet period but has an obvious change in arid period. We suggests that the arsenic has valuable potential to indicate past climatic changes in the westerly-influenced arid region. The research about the source of arsenic is conducive to the study of paleoclimate and the prevention of arsenic pollution.