Table of Geological Times
Geologists have divided the Earth's 4.6 billion years of history into eons, eras, periods, epochs, and ages. These divisions do not cover the same amount of time, but instead divide history according to the most relevant geological events that have taken place and have been recorded in the rocks.
The widest division is the aeon. Four eons are known:
The first three eons are grouped within a supereon, the Precambrian, which encompasses all time prior to the Phanerozoic.
The Phanerozoic eon is the most recent and the one we know best from the existence of fossils. It is divided into three eras:
- Paleozoic Era or Primary Era.
- Mesozoic Era or Secondary Era.
- Cenozoic Era, which includes the Tertiary and Quaternary Period.
The eras are divided into periods, and these, in times and ages.