CLST 129 Lecture Notes - Lecture 16: Homo Habilis, Fetus, Oldowan
6 Sep 2016
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Document Summary
Lecture #18 feb 23rd dating and world chronology . Similar to tl, but based on the accumulation of energy trapped in minerals when they are not exposed to the light. When buried, they start accumulating energy from the radioactivity in the soil. If exposed to the light, they will release it. The sample is hit by light of visible wavelength and the resultant luminescence is measured. The luminescence depends on time and burial conditions. Not very precise for absolute dating because of the many variables. Other absolute dating method: electron spin resonance dating (esr) Used for material which cannot be heated without damage. It measures the traces of damage caused in tissues by natural radioactivity, which are repaired in living creatures but not after their death. Especially used to date tooth enamel of humans and animals, which starts absorbing trapped energy when buried and exposed to natural radiation. Not very precise, but still useful for research on early humans.
