Problems with k ar dating seriously dating someone
The site also must be geologically meaningful, clearly related to fossil-bearing rocks or other features that need a good date to join the big story.
Lava flows that lie above and below rock beds with ancient human fossils are a good—and true—example.
Also, the cheaper K-Ar method can be used for screening or reconnaissance purposes, saving Ar-Ar for the most demanding or interesting problems.
These dating methods have been under constant improvement for more than 50 years.
The learning curve has been long and is far from over today.
With each increment in quality, more subtle sources of error have been found and taken into account.
This mineral sample is then baked gently overnight in a vacuum furnace.What simplifies things is that potassium is a reactive metal and argon is an inert gas: Potassium is always tightly locked up in minerals whereas argon is not part of any minerals. So assuming that no air gets into a mineral grain when it first forms, it has zero argon content.That is, a fresh mineral grain has its K-Ar "clock" set at zero. This dating method is based upon the decay of radioactive potassium-40 to radioactive argon-40 in minerals and rocks; potassium-40 also decays to calcium-40.Thus, the ratio of argon-40 and potassium-40 and radiogenic calcium-40 to potassium-40 in a mineral or rock is a measure of the age of the sample.