ESR dating of tephra with dose recovery test for impurity centers in quartz

The multiple-aliquot regenerative-additive method of ESR (electron spin resonance) dating was applied to Numazawa-Shibahara (Nm-Sb) tephra from Fukushima, Japan, with dose recovery tests for impurity centers in quartz. The age obtained from Ti-H center is consistent with the RTL (red thermoluminescence) and Fission Track ages while the ones from Al and Ti-Li center are overestimates. The dose recovery test indicates that the equivalent dose estimate based on the Ti-H center agrees within 6% of the expected dose (370 Gy). The dose recovery test is a useful procedure for choosing the signal appropriate for dating.