Isotopes used in radiometric dating


Its crust is continually being created, modified, and destroyed.As a result, rocks that record its earliest history have not been found and probably no longer exist.



These radioactive elements constitute independent clocks that allow geologists to determine the age of the rocks in which they occur.The radioactive parent elements used to date rocks and minerals are: Radiometric dating using the naturally-occurring radioactive elements is simple in concept even though technically complex.If we know the number of radioactive parent atoms present when a rock formed and the number present now, we can calculate the age of the rock using the decay constant.The number of parent atoms originally present is simply the number present now plus the number of daughter atoms formed by the decay, both of which are quantities that can be measured.

Samples for dating are selected carefully to avoid those that are altered, contaminated, or disturbed by later heating or chemical events.

In addition to the ages of Earth, Moon, and meteorites, radiometric dating has been used to determine ages of fossils, including early man, timing of glaciations, ages of mineral deposits, recurrence rates of earthquakes and volcanic eruptions, the history of reversals of Earth's magnetic field, and the age and duration of a wide variety of other geological events and processes.