The Geologic Time Scale

The scientific study of the origin, history, and structure of Earth and the processes that shape it.

The principle that states that all geologic change occurs suddenly:

The idea that the same geologic processes that shape Earth today have been at work throughout Earth's history:

Which were true about James Hutton?

The shortest measurement of time on the geologic time scale:

(a)  

The Earth is changed by both catastrophic events and the ongoing processes of uniformitarianism.

The _____ divides Earth's history into intervals of time defined by major events or changes on Earth.

The largest unit of geologic time:

Eons are divided into smaller units of time called:

(a)  

Eras are subdivided into smaller units called: