Geologic Time Review

Front

What epoch did modern humans first appear?

Back

Holocene

Front

What process turns plant material into stone?

Back

Petrification

Front

What is the scientifically accepted age of the Earth?

Back

4.6 billion years

Front

What is the smallest unit of geological time?

Back

Epoch

Front

What is the largest unit of geological time?

Back

Eon

Front

What are the four main eons of Earth's history?

Back

Hadean, Archean, Proterozoic, Phanerozoic

Front

What is the difference between an epoch and an era?

Back

An epoch is a smaller division of geological time than an era.

Front

What significant events mark the beginning of the Holocene epoch?

Back

The end of the last Ice Age and the rise of human civilization.

Front

What is the significance of the Cambrian explosion?

Back

It marks a period of rapid diversification of life on Earth.

Front

What is the geological time scale?

Back

A system of chronological dating that relates geological strata to time.