A stage of the Lower Proterozoic, from about 2000 to 1400 Ma ago, underlain by the Udocanian and overlain by the Burzyan (Burzyanian).
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。