potassium-argon dating

American  

[puh-tas-ee-uhm-ahr-gon] / pəˈtæs i əmˌɑr gɒn /

noun

Geology.

1. a method for estimating the age of a mineral or rock, based on measurement of the rate of decay of radioactive potassium into argon.

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potassium-argon dating British  

noun

1. a technique for determining the age of minerals based on the occurrence in natural potassium of a small fixed amount of radioisotope ⁴⁰ K that decays to the stable argon isotope ⁴⁰ Ar with a half-life of 1.28 × 10 ⁹ years. Measurement of the ratio of these isotopes thus gives the age of the mineral Compare radiocarbon dating rubidium-strontium dating

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potassium-argon dating Scientific  

1. A method of radiometric dating, involving analysis of the ratio of potassium 40 (a radioactive isotope of potassium) to argon (the product of radioactive decay of potassium 40) in a given sample.

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Etymology

Origin of potassium-argon dating

First recorded in 1965–70

Example Sentences

See Examples For:

potassium-argon dating

Using a method known as potassium-argon dating, Zinjanthropus was determined to be 1.75 million years old.

From Time Magazine Archive