Senior Secondary · 11-12 · Earth Science

Geologic Time & Earth's History

40 practice questions available.

What is the geologic time scale?

A system used by scientists to divide Earth's 4.6-billion-year history into distinct time units based on major geological and biological events

What are the major divisions of the geologic time scale, from largest to smallest?

Eon, era, period, and epoch

How old is the Earth estimated to be?

About 4.6 billion years old

What eon are we currently in?

The Phanerozoic Eon

What era are we currently in?

The Cenozoic Era, often called the 'Age of Mammals'

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