摘要
在地球发展过程中存在着３５Ｍａ的旋回周期，它不仅表现在全球性海平面变化、生物集群绝灭、构造运动幕、岩浆旋回以及石气候变化方面，而且也反映在古地磁倒转和陨击事件方面，反映了地球演化的自然阶段．重要地质事件明显地集中于特定时期，形成自然临界，其可能主要受天体运动周期的控制。
Among the cyclicity shown by the geological evolution of the earth,the periodicity of ca 35Ma is expressed most distinctly. This is evidenced not only by the global sea-level changes,biotic mass-extinctions,tectonic episodes,magmatic cycles and climatic changes,and also by the magnetic reversals and impact craterings. It is suggested that the periodicity of ca 35Ma may represent a natural stage in which the earth has evolved,and that it may be taken as an objective criterion for determining the 2nd order global sea-level cycle and its sedimentary record-the mesosequence. Major geological events in the earth′s history are clustered in specific periods,suggesting the natural crises. They are thought to have been controlled by the astronomic cycle,especially related to the crossing of the solar system through the galactic plane.
出处
《地球科学（中国地质大学学报）》
CSCD
北大核心
1996年第3期235-242,共8页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金
国家重大基础性研究项目
