Key learning points

1. Geological timescales are measured in millions of years.
2. A period is a basic unit of geological time and they last for millions of years.
3. An epoch is a subdivision of a geological time period.
4. We are currently in the quaternary period in the holocene epoch.

Keywords

• Geological time - the timeline of Earth’s history

• Eon - the largest division of geological time, lasting hundreds of millions to billions of years

• Era - a subdivision of an eon, lasting tens to hundreds of millions of years

• Period - a subdivision of an era, lasting millions of years

• Epoch - the smallest measurement of geological time, a subdivision of a period, lasting thousands to millions of years

Common misconception