摘要
湖泊沉积物是记录过去气候变迁的自然档案 ,分析湖泊沉积物的地球化学特征可以恢复湖区的古环境。在安固里淖湖心区钻取一沉积剖面 ,并以 1cm为间隔分样 ,测得剖面各段的化学元素组成。根据岩心化学元素组成和元素比值指标的变化 ,结合岩心纹层年代 ,获得湖区全新世以来的环境变化信息 :85 0 7— 745 3aBP气候略干冷 ,但向暖湿方向发展 ;745 3— 461 7aBP以湿润气候为主 ,但是存在相对干旱的时段 ( 5 1 37— 461 7aBP) ;461 7— 5 74aBP以干冷气候为主 ,在 461 7aBP和 2 4 94— 1 92 4aBP期间出现强干冷气候突变事件 ;5 74aBP以来 ,前期气候向湿润方向发展 ,但是在 383aBP以后又转为干旱。
Lacustrine sediments can record environmental changes,therefore analyzing their geochemical characters can reconstruct palaeoenvironment around lake basin. This paper makes in detail a geochemical analysis of lacustrine sediments from a core profile collected in the lacuster of Angulinao Lake, Bashang Plateau, North China. The environmental changes are confirmed by variations in concentrations of chemical elements such as Mg, Ca, Fe et al. and variations of Mg/Ca, Ca/K, Fe/Al et al.. combining with the varve chronology, Holocene environmental changes around Angulinao Lake can be speculated. In 8 507-7 453 a BP, the climate was a little dry and cold, but turned to warm and humid; In 7 453-4 617 a BP, the climate was warm and humid, but the short stage of arid existed(5 137-4 617 a BP); In 4 617-574 a BP, the climate was cold and dry, but the stronger cold and dry climates arose at 4 617a BP and in 1 924-2 494 a BP. Since 574 a BP, climate drived to humid in the earlier stage, but turned to dry since 383a BP. The climate changes around Angulinao Lake coincided with the other areas in North China at the same time.
出处
《古地理学报》
CAS
CSCD
2002年第4期55-60,共6页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金资项目 (4 0 0 0 1 0 0 3 )
关键词
全新世
湖相沉积
地球化学特征
环境变化
化学元素
古气候
Bashang Plateau, Angulinao Lake, Holocene, lacustrine sediments, geochemical characters, environmental change
