Ar ar dating method
But since floods jumble materials of different origins and ages together, that meant the scientists had to date dozens of different minerals.
The youngest crystal in the footprint layer would represent the oldest possible age for the prints; the oldest crystal in the layer above it would represent the youngest they could be.
Potassium-Argon Dating Potassium-Argon dating is the only viable technique for dating very old archaeological materials.
Geologists have used this method to date rocks as much as 4 billion years old.
One thing to keep in mind is that high-precision isotope measurements always measure ratios between isotopes, not absolute concentrations.
To understand argon-argon dating, you need to understand potassium-argon dating.
For every 100 K-40 atoms that decay, 11 become Ar-40.
And when I look at the Wikipedia article, the discussion is so technical and defensive that I can't actually picture what is going on. As noted in the comments the wikipedia articles (at the time this question was submitted) are contradictory.
There are quite a few steps to the logic of how argon-argon dating works but none are too complicated, although I won't go into all of the possible interferences.
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Visit Stack Exchange Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences. Sign up to join this community The Washington Post article Scientists discover hundreds of footprints left at the dawn of modern humanity describes the geological dating of stratified layers of mud by analyzing and dating minerals within each layer.