The geologic time scale is divided into eons, eras, periods, epochs, and ages. Our activities, and the time scale for download above, focus primarily on two of those divisions most relevant for an ...

Distinguish between geologic eons, eras and periods. Memorize the eras and periods of the geologic time scale, and the age of the boundaries between the eras. Describe early scientific attempts to ...

From the longest to the shortest and most precise, those units are eons, eras, epochs, periods and ages. ... The International Chronostratigraphic Chart of 2020. (Image credit: ...

You might know some of the big Geologic Ages, Epochs, Periods, Eras and Eons. The dinosaurs died out 66 million years ago in the Maastrichtian Age in the Late Epoch of the Cretaceous Period in the ...

The Proterozoic Eon, spanning from 2,500 million to 539 million years ago, marked a transformative chapter in Earth's history ...