摘要
对泥河湾盆地西部井儿洼钻孔上部 12 2 4m的湖相沉积物以约 0 2m的间距系统取样 ,测量其CO2 含量。以建立的时间标尺为基础 ,分析了最近 12 0 0ka以来古气候变化的周期特征。结果表明地球轨道要素偏心率、地轴倾斜变化周期的 40 0ka、10 0ka、40ka的准周期成分在湖相沉积中有明显反映 ,而岁差 2 0ka周期成分不明显 ,同时包含有 70ka、5 5ka的周期。这些结果说明第四纪古气候变化既与地球轨道要素变化有关 ,也与地球系统内部其它因素变化有关。古气候特征性周期在780ka左右出现转折 ,在此之前地球轨道周期不明显 ,在此之后出现较显著的地轴倾斜周期 46ka及31ka。
CO 2 content was sampled at every 20cm interval in upper section of Jingerwa core of lacustrine deposit with a thickness of 122.4m in the west of Nihewan basin. Based on developed time scale, the paleoclimatic periodicities of the last 1200ka have been analyzed. The strong spectral peaks near quasi-periods of 400ka, 100ka and 40ka coincide with the Earth orbital forcing. The periods of 70ka and 55ka are also involved in the climatic change. The results show that Quaternary climatic changes are associated with both the Earth orbital forcing and the inner elements of the Earth system. A turning point of characteristic periods was showed in about 780ka. There was no obviously orbital period recorded in the lacustrine deposit before 780ka, but two of the main periods , 46ka and 31ka, are coherent with the period of obliquity after 780ka.
出处
《地学前缘》
EI
CAS
CSCD
2002年第1期182-186,共5页
Earth Science Frontiers
基金
原地质矿产部"九五"重点发展计划项目"中国第四纪地表系统巨变过程"资助项目 ( 95 0 1113)
