Geography & Earth
Advanced

Radiometric Dating Age

Age of a rock from parent and daughter isotopes.

Formula

t=1λln⁡ ⁣(1+DP)t = \frac{1}{\lambda}\ln\!\left(1 + \frac{D}{P}\right)

Variables

\lambdaDecay constant
DDaughter atoms
PParent atoms

Example

Equal parent and daughter means exactly one half-life has passed

Did You Know?

Uranium–lead dating of zircon crystals is how we know the Earth is about 4.54 billion years old.

datingisotopesgeology