Thermoluminescent dating history
Thermoluminescent dating history - dating someone who has just ended his marriage
Most excited electrons will soon recombine with lattice ions, but some will be trapped, storing part of the energy of the radiation in the form of trapped electric charge (Figure 1).
Now, he believes “the Garden of Eden in Africa is probably Africa—and it’s a big, big garden.” In other words, “Long before the out-of-Africa dispersal of Hublin worked with Abdelouahed Ben-Ncer of the National Institute for Archaeology and Heritage in Rabat, Morocco, and an international team of researchers to date teeth, long bones, skulls, and tools of at least five individuals found at Jebel Irhoud.
Where there is a dip (a so-called "electron trap"), a free electron may be attracted and trapped.
The flux of ionizing radiation—both from cosmic radiation and from natural radioactivity—excites electrons from atoms in the crystal lattice into the conduction band where they can move freely.
Using new thermoluminescent dating technology on flints found surrounding the fossils, they were able to place The site at Jebel Irhoud isn’t new—it was discovered in the 1960s—but this latest excavation began in 2004.
New dating techniques allowed scientists to establish a consistent chronology for recently discovered fossils as well as to to re-date prior findings.
As time goes on, the ionizing radiation field around the material causes the trapped electrons to accumulate (Figure 2).
In the laboratory, the accumulated radiation dose can be measured, but this by itself is insufficient to determine the time since the zeroing event.
The team examined a skull originally dated as 165,000 years old, and placed it further back in time by using new techniques that measured the radioactivity of the sediment in Jebel Irhoud.
The fossil’s age, based on the latest dating methods, is consistent with the finding that at Jebel Irhoud were close relatives.
Thermoluminescence dating presupposes a "zeroing" event in the history of the material, either heating (in the case of pottery or lava) or exposure to sunlight (in the case of sediments), that removes the pre-existing trapped electrons.
Therefore, at that point the thermoluminescence signal is zero.
Ideally this is assessed by measurements made at the precise findspot over a long period.