Potassium argon dating applications
We will deal with carbon dating first and then with the other dating methods.Carbon has unique properties that are essential for life on Earth.Familiar to us as the black substance in charred wood, as diamonds, and the graphite in “lead” pencils, carbon comes in several forms, or isotopes.
This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.
Anything over about 50,000 years old, should theoretically have no detectable C.
So, we have a “clock” which starts ticking the moment something dies.
Obviously, this works only for things which were once living.
It cannot be used to date volcanic rocks, for example.The rate of decay of N in 5,730 years (plus or minus 40 years).