Rocks and Fossils Are Evidence of Earth's History

Front

What method do scientists use to estimate the age of the Earth?

Back

By using radiometric age dating of meteorite material.

Front

How do index fossils assist in determining the age of rock layers?

Back

By comparing the index fossils with fossils in the same layer.

Front

What does the Law of Original Horizontality state?

Back

It states that sedimentary layers are deposited horizontally under the influence of gravity.

Front

What is the significance of the Law of Superposition?

Back

It states that the youngest rock layers are at the top and the oldest are at the bottom.

Front

How does the position of fossils in sedimentary rock layers indicate their age?

Back

The rocks and fossils in a higher layer are younger than those in a lower layer.

Front

What is radiometric dating?

Back

A method used to date materials by comparing the abundance of a radioactive isotope to its decay products.

Front

What are index fossils?

Back

Fossils of organisms that were widespread but only existed for a short period, used to date rock layers.

Front

What is the principle of faunal succession?

Back

It states that sedimentary rock layers contain fossilized flora and fauna that succeed each other in a definite and recognizable order.

Front

What is the difference between relative age and absolute age?

Back

Relative age is the age of an object in relation to another, while absolute age is the actual age in years.

Front

What is the importance of sedimentary rock layers in Earth's history?

Back

They provide a record of past environments, climate changes, and biological evolution.