Paleontology seeks to map out how life evolved across geologic time.
A substantial hurdle is the difficulty of working out fossil ages.
Strata are differentiated from each other by their different colors or compositions and are exposed in cliffs, quarries, and river banks.
These rocks normally form relatively horizontal, parallel layers, with younger layers forming on top.
is a technique used by scientists to learn the ages of biological specimens – for example, wooden archaeological artifacts or ancient human remains – from the distant past.
It can be used on objects as old as about 62,000 years.
Follow the links below to learn more about radiocarbon dating. Radiocarbon dating uses carbon isotopes A special kind of radiocarbon dating: Bomb radiocarbon dating What is an isotope?
They have the same ratio of carbon-14 to carbon-12 as the atmosphere, and this same ratio is then carried up the food chain all the way to apex predators, like sharks.After plants die or are consumed by other organisms, the incorporation of all carbon isotopes, including 14C, stops.Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of 14C. ) Comparing the remaining 14C fraction of a sample to that expected from atmospheric 14C allows us to estimate the age of the sample.Radiocarbon dating (usually referred to simply as carbon-14 dating) is a radiometric dating method.It uses the naturally occurring radioisotope carbon-14 (14C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years old.