Examples of relative dating in geology Sites like chatroulette for sex
The atoms of some chemical elements have different forms, called isotopes.
These break down over time in a process scientists call radioactive decay.
Unlike people, you can’t really guess the age of a rock from looking at it.
Others measure the subatomic particles that are emitted as an isotope decays.
Some measure the decay of isotopes more indirectly.
For example, the decay of potassium-40 to argon-40 is used to date rocks older than 20,000 years, and the decay of uranium-238 to lead-206 is used for rocks older than 1 million years.
Radiocarbon dating measures radioactive isotopes in once-living organic material instead of rock, using the decay of carbon-14 to nitrogen-14.
Pretty obvious that the dike came after the rocks it cuts through, right?