Relative dating earth layers
Scientists need to understand radioactive decay in order to absolute date.
Atoms decay by losing a neutron and gaining a proton.
A half-life is the time it takes for half of the atoms in an isotope to decay. Two half lives is 11,460 years and three half lives is 17,190 years.
Given enough half lives, there eventually isn't enough carbon that remains.
They can show how some species lived and what specie replaced them.
They also demonstrate that some species haven't changes all that much.
Uniformitarianism states that the processes occurring today are similar to those that occurred in the past.
So if Uranium-238 is decaying at a specific rate, then scientists believe that it decayed at the same rate throughout the ages.
Another scientist named Lyell took it a little further by dating some of the Earth processes.You can tell that a batholith is younger than the layers that are on top because a batholith intrudes into current layers In the left image above, you can see the relative order in which each even and layer occurred.Layers 4 and 8 represent periods of erosion by using squiggly lines. Using deductive reasoning, tell a story in chronological order. There are a few techniques used to help us relatively date rock strata. In the image below, you will see the tracks of a bird, barefoot woman, a business man, a motorcycle, and a really small clown car.