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cosmic rays. e.g. quartz grain/coral/mollusc shell. Thorium. Uranium. Potassium. Principle of Electron Spin Resonance dating. ESR dating in earth sciences and achaeology refers to the effect
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cosmic rays e.g. quartz grain/coral/mollusc shell Thorium Uranium Potassium Principle of Electron Spin Resonance dating ESR dating in earth sciences and achaeology refers to the effect of accumulated radiation in a mineral relative to time. Thus, it is – just as luminescence – an „absolute“ dating method. Paramagnetic centres are detected in the crystal lattice of the mineral by means of microwave absorption spectroscopy.
A B Al-impurity centre Ti-impurity centre Relative ESR-signalintensity Magnetic field [Gauss] Principle of Electron Spin Resonance dating A = rotating electron creates a magnetic moment B = resonance occurs after microwave absorption C = the absorbed microwave is transformed into an ESR-signal by the spectrometer. Wagner, G.A. (1995)
Principle of Electron Spin Resonance dating The height of the ESR signal is a measure of the radiation dose experienced by the sample, and thus of the time since the signal was last zeroed. At the Geography Department in Cologne, the newest spectrometer by Bruker, the Elexys 500 spectrometer (X-band), is at use.