Ch 12: Geologic Time Scale

Front

What is the Geologic Time Scale?

Back

A system used by geologists to describe the timing and relationships of events in Earth's history.

Front

What is the largest interval of geologic time?

Back

Eon

Front

What era is known as the age of dinosaurs?

Back

Mesozoic Era

Front

How long ago did dinosaurs die out?

Back

65 million years ago.

Front

True or False: Geologists subdivide periods into eras.

Back

False

Front

What are the three eras of the Phanerozoic Eon?

Back

Paleozoic, Mesozoic, and Cenozoic.

Front

What is the estimated age of Earth?

Back

Approximately 4.6 billion years ago.

Front

What does the Geologic Time Scale outline?

Back

The life forms on Earth and Earth's geologic history.

Front

What is the smallest unit of geologic time?

Back

Epoch.

Front

What is the difference between an era and a period?

Back

An era is a larger division of time than a period.