成冰纪全球冰期事件的环境效应研究进展

Research progress on environmental effects of the Cryogenian global glaciation

成冰纪全球冰期是地球历史上最极端的冰室气候事件,冰川作用波及赤道区域,全球可能都遭受了冰封,海洋广泛缺氧,生物演化进程迟滞。然而,冰期结束之后,大气氧浓度迅速升高,海洋发生逐步氧化,大型带刺疑源类和真核多细胞藻类在埃迪卡拉纪开始繁盛,出现最早的动物,地表生物圈发生了翻天覆地的变化。显然,成冰纪全球冰期事件是地球系统演化的重要转折。认识冰期的环境效应是认识埃迪卡拉纪生物演化的关键,也是打开地表宜居环境演化的钥匙。本文总结了近年来成冰纪全球冰期的气候假说、冰期沉积特征、海洋氧化还原条件及冰期后的大气与海洋环境剧变等方面的研究进展,简要分析了全球冰期研究中存在的问题,并对该领域未来研究提出了展望与建议。

The Cryogenian global glaciation events are Earth's most extreme icehouse climate.During these glaciations,ice sheets extended to the equatorial region.It is suggested that the ocean was completely frozen and suffered from widespread marine anoxia,which delayed biological evolution.After the end of the glaciation,atmospheric oxygen levels significantly increased,leading to deep-ocean oxidation and the diversification of multicellular algae in the early Ediacaran.Obviously,the Cryogenian global glacial event was an important turning point in the evolution of the Earth system.Understanding how the glaciations altered the environment is the key to understanding biological evolution,and the habitable environment of the Ediacaran Period.The present paper provides a summary of recent research progress in the areas of climate hypothesis,glacial sedimentation characteristics,ocean redox conditions,and post-glacial atmospheric and marine environment drastic changes during the global glacial period.It also briefly analyzes the existing problems in global glacial research and proposes future research directions.