Radiometric dating

Uranium series U-series dating is based on the uranium and thorium radioactive decay chains. These decay chains involve a series of different elements and may be as long as 35 steps, before reaching the stable end product — lead. These elements are usually present in constant equilibrium amounts in a sample, as long as the system remains closed. A closed system is one in which there is no free exchange of elements in a material with the outside environment.

This same principle can be used to date corals, as again, the presence of thorium in the corals will be the result of uranium decay – not because the thorium has.

There in was given evidence that the measuring of thermoluminescence emitted from objects made of fired clay could be effectively used for the dating and verification of such objects. Quarz and feldspar as well as a number of other minerals have the ability to store energy generated by radioactive radiation. Under exposure to great heat such minerals release this energy again in form of light impulses. Clay, which is used in the production of every day objects as well as objects of art, generally contains such minerals and radioactive isotopes.

All radioactive energy accumulated and stored by the unfired clay in geological time is destroyed at the point of firing. After a period of cooling the energy storing process starts anew and a certain amount of stored energy is gained annually. At the re-heating of a material sample taken from the fired object impulses of emitted light can be measured in the laboratory which correspond with the time interval between the present observation and the last firing. These findings have provided us with the basic principles of scientific dating methods.

Result provides a statement on the last time of firing. TL measurements to specify age can be falsified if objects have been subjected to high X andY radiation doses or neutron bombardment.