[roo-bid-ee-uh m-stron-shee-uh m, -shuh m, -tee-uh m]

nounGeology.

a radiometric dating method whereby the ratio of rubidium isotope to strontium in a mineral is used to calculate the age of the mineral, based on the rate of radioactive decay of rubidium to strontium.

British Dictionary definitions for rubidium-strontium dating

rubidium-strontium dating

noun

a technique for determining the age of minerals based on the occurrence in natural rubidium of a fixed amount of the radioisotope 87 Rb which decays to the stable strontium isotope 87 Sr with a half-life of 4.7 × 10 11 years. Measurement of the ratio of these isotopes thus gives the age of a mineral, for ages of up to about 4 × 10 9 years