摘要
除周期性气候波动外，新生代气候变化的基本特征是阶梯状气候变冷、波动幅度的不断增加和气候波动周期的转变。深海氧同位素记录表明新生代曾发生至少三次快速变冷事件，它们分别发生在３６，１５和２．４ＭａＢＰ前后。根据来自北大西洋的深海氧同位素记录，第四纪气候变化的趋势是波动幅度增加、频率降低。Ｂ／Ｍ界限附近，气候波动周期由４１ｋａ转变为１００ｋａ。黄土高原上黄土地层与磁化率研究揭示，现代东亚季风出现于２．４Ｍａ前，并于１．１和０．６ＭａＢＰ前后两度加强，现在的季风环流形势形成于０．６ＭａＢＰ，米兰柯维奇理论不能解释上述新生代气候的阶梯状变冷、第四纪气候的阶段性和东亚季风的形成及加强，因此除轨道因素外，还有别的因素控制气候变化。
The step-like cooling, the continuous increase of fluctuation amplitude and the transition of fluctuatin period are basic characteristics of the Cenozic climatic changes in addition to period fluctuation. Deep sea Oxygen isotopic data indicated that there were at least three rapid cooling events in the Cenozoic Era, which happened respectively at 36 Ma,15 Ma and 2. 4 Ma BP. According to deep sea oxygen isotopic records from the North Atlantic , The trends of the Quaternary climatic changes are the increase in fluctuatin amplitude and the decrease in fluctuation frequency. The period of climatic fluctuation changed from 41 ka to 100 ka at B/M boundary. The studies of loess stratigraphy and susceptibility in the loess plateau have shown that the modern East Asia Monsoon circulation was established 2. 5 Ma ago and strengthened twice at 1. 1 Ma BP and 0. 6 Ma BP. The present monsoon circulation has not appeared until 0. 6 Ma BP. Milankovitch theory is unable to explain the steplike cooling in Cenozoic, stage development of Quaternary climate and the formation and strengthening of the East Asia Monsoon. Therefore, there must be other factors controlling climatic changes in Cenozoic beside the earth's orbit factors.
出处
《兰州大学学报（自然科学版）》
CSCD
北大核心
1995年第3期120-128,共9页
Journal of Lanzhou University(Natural Sciences)
基金
国家八五攀登计划青藏项目
国家自然科学基金
