Materials such as rocks and carbon often contain small traces of radioactive isotopes.
By comparing the relative amount of the isotope with that found in nature an estimate of the materials age can be obtained. 2] '''Potassium Argon (K–Ar) Dating''' Potassium-40 is a radioactive isotope that will spontaneously decay into argon-40, another radioactive isotope.
Students, not their school, make the choice to write Optional exams.
If students choose to write these exams, results will count for 40 percent of the final course mark.
Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale.
Other relative methods include chemical dating, biostratigraphic or faunal dating, and cultural dating.
Chemical dating, such as fluorine dating, compares the relative amounts of absorbed fluorine in bones from the same site.
Scientific knowledge of Earth’s geologic history has advanced significantly since the development of radiometric dating, a method of age determination based on the principle that radioactive atoms in geologic materials decay at constant, known rates to daughter atoms.
Radiometric dating has provided not only a means of numerically quantifying geologic time but also a tool for determining the...