Types of geological time period
- en geological age (n) ➜
- en geological epoch (n) ➜
- en geological era (n) ➜
- en geological period (n) ➜
Links to other resources
- umbel.org /umbel/sc/GeologicalTimePeriod
- sw.opencyc.org /2012/05/10/concept/en/GeologicalTimePeriod