ESR dating of elephant teeth and radiation dose rate estimation in soil

Chemical analysis of 238U, 232Th and 40K in the dentine as well as enamel of elephant tooth fossil has been carried out in order to estimate the internal absorbed dose rate of the specimens, which was estimated to be (39 +/- 4) mrad/y on the assumption of early uptake model of radionuclides. The external radiation dose rate in the soil including the contribution from cosmic rays was also estimated to be (175 +/- 18) mrad/y with the help of gamma-ray spectroscopic techniques of the soil samples in which the specimens were buried. The 60Co gamma-ray equivalent accumulated dose of (2 +/- 0.2) x 10(4) rad for the tooth enamel gave "ESR age" of (9 +/- 2) x 10(4) y, which falls in the geologically estimated range between 3 x 10(4) and 30 x 10(4) y before the present.