Radiocarbon dating measures radioactive isotopes in once-living organic material instead of rock, using the decay of carbon-14 to nitrogen-14.
Absolute and relative dating geology
Absolute age dating is like saying you are 15 years old and your grandfather is 77 years old.
Absolute and relative dating of rocks
Another example is luminescence dating, which measures the energy from radioactive decay that is trapped inside nearby crystals.
Absolute and relative dating examples
Dating is used to arrange geological events, and the rocks they leave behind, in a sequence.
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.
They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of years.
If a rock has been partially melted, or otherwise metamorphosed, that causes complications for radiometric (absolute) age dating as well.