Front

What do scientists use to help determine geologic time?

Back

Rock layers.

Front

What type of dating do scientists use to determine the exact age of geological materials?

Back

Absolute dating.

Front

What is the process called when sediment is moved around by wind or water?

Back

Erosion.

Front

How long is Earth's history represented in the geologic time scale?

Back

4.6 billion years.

Front

In which era did dinosaurs live?

Back

Mesozoic era.

Front

What are the three main types of rock?

Back

Igneous, sedimentary, and metamorphic.

Front

What is the principle of superposition in geology?

Back

In an undeformed sequence of sedimentary rocks, the oldest layers are at the bottom and the youngest are at the top.

Front

What is relative dating in geology?

Back

A method of determining the age of rocks and fossils in relation to one another.

Front

What is the significance of the fossil record in understanding geologic time?

Back

It provides evidence of the history of life and the changes in organisms over time.

Front

What is a geological epoch?

Back

A subdivision of geological time that is longer than a stage and shorter than a period.