rubidium-strontium dating

US: (ro̅o̅ bid′ē əm stron′shē əm, -shəm, -tē əm)

WordReference Random House Unabridged Dictionary of American English © 2025

ru•bid′i•um-stron′ti•um dat′ing  (ro̅o̅ bid′ē əm stron′shē əm, -shəm, -tē əm), [Geol.]

1. Geology 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.

• 1965–70

Collins Concise English Dictionary © HarperCollins Publishers::

rubidium-strontium dating noun

1. a technique for determining the age of minerals based on the occurrence in natural rubidium of a fixed amount of the radioisotope ⁸⁷Rb which decays to the stable strontium isotope ⁸⁷Sr with a half-life of 4.7 × 10¹¹ years. Measurement of the ratio of these isotopes thus gives the age of a mineral, for ages of up to about 4 × 10⁹ years