Define relative dating techniques
Which of these does a better job of describing my age? So, in both geology and paleontology, we want to be able to point to an object and say exactly how old it is.To do that, we have to learn a little bit about radioactive decay.Scientists know that the layers they see in sedimentary rock were built up in a certain order, from bottom to top.When they find a section of rock that has a lot of different strata, they can assume that the bottom-most layer is the oldest and the top-most layer is the youngest.
We'll explore both relative and numerical dating on our quest to understand the process of geological dating.
In 1905, Ernest Rutherford figured out that we could use radiation to establish the ages of rocks.
By studying how the mass of uranium changed with radioactive decay, Rutherford was able to determine the age of a rock containing a uranium mineral. It meant that scientists could suddenly establish the actual ages of all their rocks and fossils!
Let's say that Paul the Paleontologist found an iguanodon fossil in the light green layer shown above.
And, he also found a coelophysis fossil in the yellow layer. Of course, the coelophysis, which means that coelophysis came before iguanodon.