A S. African stage of the Archaean, from about 4000 to 3000 Ma ago, followed by the Randian, that includes the Onverwacht, Figtree, and Pongola sequences of S. Africa.
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。