Dating techniques based on radioactive decay
Radioactive elements were incorporated into the Earth when the Solar System formed.
Over the second half-life, of the atoms remaining decay, which leaves of the original quantity, and so on.In addition, any argon that existed prior to the last time the rock was molten will have been driven off by the intense heat.As a result, all of the argon-40 in a volcanic rock sample is assumed to date from that time.Carbon-14 is a method used for young (less than 50,000 year old) sedimentary rocks.
This method relies on the uptake of a naturally occurring radioactive isotope of carbon, carbon-14 by all living things.
Specifically, the electrons of quartz, feldspar, diamond, or calcite crystals can become displaced from their normal positions in atoms and trapped in imperfections in the crystal lattice of the clay molecules.