Geologists obtain a wide range of information from fossils. They help us to understand evolution, and life in general; they provide critical information for understanding depositional environments and changes in Earths climate; and they can be used to date rocks.

What is the name for fossils that are very useful in geologic dating?

index fossils Organisms that lived for relatively short time periods are particularly useful for dating rocks, especially if they were distributed over a wide geographic area and so can be used to compare rocks from different regions. These are known as index fossils.

How do you date rocks and fossils?

To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

Can you use fossils to date rocks?

Geologists obtain a wide range of information from fossils. They help us to understand evolution, and life in general; they provide critical information for understanding depositional environments and changes in Earths climate; and they can be used to date rocks.

What are the three types of fossils?

Scientists categorize fossils into three main groups – impression fossils, trace fossils, and replacement fossils. Amber is also often looked at as a fourth type of fossil. Although a chunk of amber can contain insects that were trapped in resin long ago, technically it is still categorized as a gemstone.

What is a fossil in a rock?

What is a fossil? Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Fossils also include any preserved trace of life that is typically more than 10 000 years old.