摘要
临夏盆地东山古湖（２．３５～１．６５ＭａＢ．Ｐ．）沉积厚达８４ｍ，是六盘山以西早更新世湖相沉积的典型代表。以２．５ｍ的间隔对其进行系统采样，以ＣａＣＯ３含量变化为指标建立高分辨率的气候变化曲线，对曲线进行周期分析表明，东山古湖所反映的气候波动具有明显的４１０００ａ主导周期；其中２．２８ＭａＢ．Ｐ．和１．７５～１．８０ＭａＢ．Ｐ．时段为两个明显的冷湿时期，表明东亚季风在建立初期具有不稳定性。
A total of 3267 carbonate samples were taken with 2.5 cm interval from 84 m thick lacustrine deposits in Linxia Basin. The carbonate content is employed as a proxy of climate records. The spectrum analysis results show that in the period of 2.35-1.65 Ma B.P., the paleoclimate had a clear 41000 a dominant periodicity, suggesting that the earth's obliquity change was the main cause of climate change over this period. The results also show there were two obvious humid periods happening at 2.28 Ma and 1.75-1.80 Ma B.P. respectively, suggesting that the monsoon climate was not stable in the Early Pleistocene.
出处
《地理科学》
CSSCI
CSCD
北大核心
1998年第4期349-354,共6页
Scientia Geographica Sinica
基金
国家自然科学基金
八五"攀登"计划资助
西南师范大学博士启动基金
关键词
早更新世
古气候
临夏盆地
古湖泊
沉积
Early Pleistocene
Climate change
East Asia monsoon
Linxia Basin
