ESR dating of sea-floor hydrothermal barite: contribution of ²²⁸Ra to the accumulated dose

Abstract

Electron spin resonance (ESR) dating of barite has been recently developed and is now practically applied to barite extracted from sea-floor hydrothermal deposits. The evolution of the accumulated dose to barite is simulated for an actual sample of barite in sea-floor hydrothermal sulfide deposit to find that the contribution of radioactive nuclei of 228 Ra series can be important for the samples younger than 300 years old. Currently, any date over 50 years should be considered a maximum value when the 228 Ra content is not obtained. The method to estimate the contribution from 228 Ra series has to be developed in future for those in which 228 Ra is not detected. The age limit of ESR dating of barite would be 5000 to 6000 years due to the decay of 226 Ra, which is also found by simulation of the accumulated dose.

Study on the design of heating and energy saving of enclosure structure of rural self-built houses

“…Due to the absence of solar radiation at night, the ambient temperature decreases, and the phase change material in the phase change wall will release the stored heat. Due to the barrier of the insulation layer, most of the heat will be transferred indoors to maintain the indoor temperature stability [12]. In addition, a temperature sensor can be set in the water outlet or phase change layer of the phase change wall.…”