Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.In a way this field, called geochronology, is some of the purest detective work earth scientists do.Watch the video to see how and download the student handout (word document).
Absolute age dating is like saying you are 15 years old and your grandfather is 77 years old.
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This rule is common sense, but it serves as a powerful reference point.
Scientists look at multiple sources for evidence that a species has evolved overtime. You can use M & M"s to simulate how radioactive decay actually works.
They use a technique called radiometric dating to determine the absolute age of a fossil.
Geologists draw on it and other basic principles ( to determine the relative ages of rocks or features such as faults.