As the atoms of an element are struck by high energy photons from the x-ray source, electrons from the inner shells are knocked from their orbits around the nuclei of the atoms, causing those atoms to become unstable ions. To re-establish stability, electrons from the next higher shell move to the vacant inner orbits emitting energy as they move.
This phenomenon is referred to as fluorescence. Since each element maintains a different electron shell configuration, the spectrum produced by each episode of fluorescence is unique, allowing the element to be identified.”
Now think about how important this actually is. After a century of guessing and making assumptions about the chemical contents of the paint used in producing pictographs we can now know exactly what those elements are! Think of what a database this will eventually be.
In a future posting I will discuss some of the results of their studies.
Bonita Newman is an archaeologist with ICI Corporation, Virginia Beach, VA., and is currently a member of the board of directors of the Colorado Rock Art Association. Lawrence Loendorf is a noted rock art researcher, a former president of the American Rock Art Research Association, and is a retired New Mexico State University professor.