Does radiometric dating always involve carbon
Argon in molten rock can just bubble out and escape.Once the rock cools and solidifies, Argon that is formed by radioactive decay is trapped inside.All radioactive atoms decay to become a more stable kind of atom.
Another possible scenario involves U leakage, again possibly as a result of a metamorphic event.
We can also construct a Concordia diagram, which shows the values of Pb isotopes that would give concordant dates.
The Concordia curve can be calculated by defining the following: ).
As no Argon was present in the rock when it first solidified, all Argon in the rock is due to the radioactive decay of Potassium.
By measuring the amounts of Potassium and Argon present we can date volcanic rocks that are millions of years old.
If a zircon crystal originally crystallizes from a magma and remains a closed system (no loss or gain of U or Pb) from the time of crystallization to the present, then the Discordant dates will not fall on the Concordia curve.