火山灰と堆積物のESR年代測定  [in Japanese] ESR dating of volcanic ash  [in Japanese]

Dating of volcanic ash and sediment by electron spin resonance (ESR) is described. In both cases dating material is quartz and ESR signals of radiation-induced centers of E', Ge, OHC, Al, Ti in quartz are used. The ESR ages of chert, flint, quartz-contained tuff and tephra are obtained. More recently the plagioclase and zircon separated from volcanic ash are used for dating. The ESR ages of sediments-wind-blowns and, beach sand and baked sand are obtained. However, in this case the ESR age can not be obtained unless the bleaching of ESR signal by light is evaluated accurately.