Geologic Time Line

The purpose of this geologic time line is to help you easily find in-depth information on eons, eras, and periods of earth’s history. We think it is convenient and useful to see the time periods all laid out in chart form. As a reference tool, you can easily note the sequence of the various divisions and the length of each unit of time. Just like the layers of the earth, the top divisions of the chart represent the most recent time. Moving down the chart, you go further and further back in time.

The names of each Eon, Era or Period are linked to pages that contain information on the geology, biology, and climate of that particular time. Note: At present, information about individual epochs can be found within their respective periods.

Below the chart, you will find links to lesson plans and activities for kids related to the geologic time line.

Eon

Era

Period

Epoch

Old Periods

Phanerozoic
Eon
543 mya to Present

Cenozoic Era
65 mya to Present

Neogene

Holocene

Quaternary

1.8 mya to Present

Pleistocene

Pliocene

Tertiary

65 to 1.8 mya

Miocene

Paleogene

Oligocene

Eocene

Paleocene

Mesozoic Era
248 mya to 65 mya
Cretaceous   144 mya to 65 mya

Jurassic   206 to 144 mya

Triassic   248 to 206 mya

Paleozoic Era
543 to 248 mya
Permian   290 to 248 mya

Carboniferous   354 to 290 mya

Devonian   417 to 354 mya

Silurian   443 to 417 mya

Ordovician   490 to 443 mya

Cambrian   543 to 490 mya

Precambrian Time
4,500 to 543 mya
Proterozoic Era 2,500 to 543 mya

Archaean 3,800 to 2,500 mya

Hadean 4,500 to 3,800 mya