Their findings suggest that the forces that lead to an eruption move much more rapidly than previously believed.They claim new magma moves beneath Yellowstone only decades before a devastating eruption.The methods that are used depend on the presumed age of the site from which they were excavated.

When a fossil is sandwiched between two such volcanic deposits, their potassium-argon dates provide a minimum and maximum age.This causes them to give off their stored energy in the form of light impulses (photons). A similar effect can be brought about by stimulating the sample with infrared light.The intensity of thermoluminescence is directly related to the amount of accumulated changes produced by background radiation, which, in turn, varies with the age of the sample and the amount of trace radioactive elements it contains..The atoms of crystalline solids, such as pottery and rock, can be altered by this radiation.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.