Robbie is trying to learn as much as he can about a rock that he found. This particular rock contains some fossils. What can Robbie learn from the fossils?

Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods. This uses radioactive minerals that occur in rocks and fossils almost like a geological clock. It's often much easier to date volcanic rocks than the fossils themselves or the sedimentary rocks they are found in.