Using a technique called uranium series
dating, a laser was used to make microscopic holes in the fossil and measure the ratio between tiny traces of radioactive elements.
There are three naturally occurring radioactive series, and two of these series, termed the "actinium series" and "uranium series
," are headed by [sup.235]U and [sup.238]U, respectively.
Uranium-238 is usually an a emitter (occasionally it undergoes spontaneous fission), decaying through the "Uranium Series
" of nuclear decay, which has 18 members, all of which eventually decay into lead-206 by a variety of different decay paths.
The new dating - using three technologies (electron spin resonance, uranium series
isotopic analysis and infrared luminescence dating) - establishes the mandible as the easternmost European fossil of its age, sharing far more in common with African and Asian fossils than with contemporary examples from western Europe.
(2004) studied uranium series
isotopes in the Avon Valley, west and southwest of the Three Mile Plains area.