Potassium-argon dating (Aldrich and Nier)
Datación potasio-argón (Aldrich y Nier)
- Date
- 1948-1957 · confidence high
- Place
- Minneapolis, Minnesota, United States
- Credited to
- Lawrence Aldrich and Alfred Nier
- Field
- Cosmos & Earth
What was discovered
Aldrich and Nier showed in 1948 that the argon-40 in potassium minerals comes from the decay of potassium-40, which made it possible to date volcanic rocks from tens of thousands to billions of years. The technique dated magnetic field reversals and hominin sites.
Its practical application to geochronology was developed in the 1950s (Wasserburg, Evernden, Curtis); 40K had been pointed to by Weizsäcker in 1937 as the source of terrestrial argon.
What it led to
- the Cenozoic magnetic reversal time scale
- dating of human evolution sites (Olduvai)
- dating of volcanic rocks and the ocean floor