An era, 3200–2800 Ma ago, of the Archaean eon, preceded by the Palaeoarchaean and followed by the Neoarchaean eras. The first direct evidence of life is from this time, and the earliest (Pongola) glaciation occurred.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。