See Also: potassium-argon dating(encyclopedia)
argon(dictionary)
argon(encyclopedia)
argon(dictionary)
argon(medicine)
Argon laser(health)
dating(encyclopedia)
Value dating(finance)
Dating(finance)
Value dating(money)

potassium-argon dating (sh)




Method for determining the age of igneous rocks based on the amount of argon-40 in the rock.

Radioactive potassium-40 decays to argon-40 with a half-life of about 1.3 billion years, making this method useful for dating rocks that are billions of years old. A more sophisticated method, called argon-argon dating, provides a more accurate estimate of the original potassium-40 content by means of the ratio of argon-40 to argon-39 in the rock, thus yielding a more accurate age determination. See also dating.