古气候变化对大同盆地第四纪沉积物中砷富集过程的影响  

Impact of Paleoclimate on Arsenic Accumulation in the Quaternary Sediments of Datong Basin, Northern China

作　　者：何俊蓉 谢先军[1] 池泽涌 刘文静 皮坤福[1] He Junrong;Xie Xianjun;Chi Zeyong;Liu Wenjing;Pi Kunfu(School of Environmental Studies, China University of Geosciences(Wuhan), Wuhan 430074, China)

机构地区：[1]中国地质大学(武汉)环境学院

出　　处：《地质科技情报》2019年第5期212-219,共8页Geological Science and Technology Information

基　　金：国家自然科学基金项目(41772255)

摘　　要：为揭示古气候变化对大同盆地第四纪含水层中砷(As)富集的影响,对盆地中部的第四系沉积物钻孔样品进行了地球化学分析。结果表明,大同盆地第四系沉积物中的铁矿物、黏土矿物以及有机质均为As的重要赋存载体。根据沉积物地球化学特征,可将沉积物由深到浅依次划分为4层,分别对应中更新世暖湿期、中更新世干冷期、末次间冰期暖湿期及末次冰期的干冷期。暖湿期沉积物中的As及铁矿物、黏土矿物、有机质含量均明显高于干冷期,说明暖湿气候更有利于铁矿物、黏土矿物和有机质在沉积物中埋藏堆积,促进了沉积物中As的富集。In order to reveal the impact of paleoclimate on the accumulation of arsenic in the Quaternary aquifer of Datong Basin, sediment samples from center of the basin were collected for geochemical analysis. The results indicate that iron minerals, clay minerals, and organic matters are all the important carriers of arsenic. According to the geochemical characteristics, the sediments can be divided into four layers corresponding to the Middle Pleistocene warm-humid climate, the Middle Pleistocene arid-cold climate, the last Interglacial warm-humid climate, and the last glaciation arid-cold climate, respectively. The As content, iron minerals, clay minerals, and organic matters are all increased during warm-humid climate period compared to arid-cold climate. This suggests that a warm-humid climate is favorable for the accumulation of Fe minerals, clay minerals, and organic matters in the sediments, and promotes the accumulation of arsenic in the sediments.

关 键 词：砷 古气候 沉积物 化学风化 大同盆地 

分 类 号：X141[环境科学与工程—环境科学] P534.63[天文地球—第四纪地质学]