Geologic Time Scale Quick Check

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Question
Why are time periods on the geologic time scale not even in length?(1 point)
Responses

They are based on a different type of calendar used to track Earth’s history.
They are based on a different type of calendar used to track Earth’s history.

They are based on important events that happened in Earth’s history.
They are based on important events that happened in Earth’s history.

They are based on the type of fossils found in rock layers of the Earth.
They are based on the type of fossils found in rock layers of the Earth.

They are based on the thickness of the Earth's rock layers.

1 answer

The correct response is: They are based on important events that happened in Earth’s history.

The divisions of the geologic time scale are determined by significant geological and biological events, such as mass extinctions or the emergence of new species, rather than being evenly spaced in time.