Problems with dating metamorphic rocks
Additionally, elements may exist in different isotopes, with each isotope of an element differing in the number of neutrons in the nucleus.A particular isotope of a particular element is called a nuclide. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide.
Any dead material incorporated with sedimentary deposits is a possible candidate for carbon-14 dating.
A commonly used radiometric dating technique relies on the breakdown of potassium (Ar in an igneous rock can tell us the amount of time that has passed since the rock crystallized.
If an igneous or other rock is metamorphosed, its radiometric clock is reset, and potassium-argon measurements can be used to tell the number of years that has passed since metamorphism.
Radioactive elements are unstable; they breakdown spontaneously into more stable atoms over time, a process known as radioactive decay.
Radioactive decay occurs at a constant rate, specific to each radioactive isotope.