Electron spin resonance dating
Electron spin resonance dating was first introduced to the science community in 1975, when Motoji Ikeya dated a speleothem in Akiyoshi Cave, Japan.ESR dating measures the amount of unpaired electrons in crystalline structures that were previously exposed to natural radiation.
These dates overlap with a period of abrupt increase in rainfall in northeast Brazil, and it is possible that this environmental change is related to the formation of this deposit.Radioactivity causes negatively charged electrons to move from a ground state, the valence band, to a higher energy level at the conduction band.After a short time, electrons eventually recombine with the positively charged holes left in the valence band.Currently we are developing a semi automated ESR dating system combined with an X-ray source and a heater to make it possible to do single aliquot ESR dating.a technique for investigating paramagnetic substances by subjecting them to high-frequency radiation in a strong magnetic field.This work presents the ESR dating of two teeth, one of Gomphotheriidae and other of Toxodontinae.
Dose–response curves of each sample were constructed using spectra acquired with a JEOL FA-200 X-Band spectrometer resulting in equivalent dose ( in age was made using ROSY ESR dating software resulting in 26±4 and 22±3 ka.
Age of substance can be determined by measuring the dosage of radiation since the time of its formation.
Electron spin resonance dating can be described as trapped charge dating.
Voinchet P, Despriée J, Tissoux H, Falguères C, Bahain JJ, Gageonnet R, Dépont J & Dolo JM (2010) ESR chronology of alluvial deposits and first human settlements of the Middle Loire Basin (Region Centre, France).
A new JEOL X-band (ca, 9.4 GHz) electron spin resonance spectrometer (JEOL FA 100) was installed.
The dating range is dependent on the nature and state of conservation of the sample and the surrounding environment but is between a few thousands and a couple of million years.