Radiometric dating age ranges
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.
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.
The above equation makes use of information on the composition of parent and daughter isotopes at the time the material being tested cooled below its closure temperature.
Plotting an isochron is used to solve the age equation graphically and calculate the age of the sample and the original composition.
A related method is ionium—thorium datingwhich measures the ratio of ionium thorium to thorium in ocean sediment.
Radiometric dating (often called radioactive dating) is a technique used to date materials such as rocks or carbon, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of the Earth itself, and can be used to date a wide range of natural and man-made materials.
In the argon-argon method the rock is placed near the center of a nuclear reactor for a period of hours.All rocks and minerals contain long-lived radioactive elements that were incorporated into Earth when the Solar System formed.These radioactive elements constitute independent clocks that allow geologists to determine the age of the rocks in which they occur.This is well-established for most isotopic systems.However, construction of an isochron does not require information on the original compositions, using merely the present ratios of the parent and daughter isotopes to a standard isotope.