ESR DATING OF BARITE IN SULPHIDE DEPOSITS FORMED BY THE SEA-FLOOR HYDROTHERMAL ACTIVITIES

摘要

Barite is a mineral newly found to be practically useful for electron spin resonance (ESR) dating of sulphide deposits formed by the sea-floor hydrothermal activities. The recent studies for the properties of the ESR dating signal in barite are summarised in the present paper as well as the formulas for corrections for accurate dose-rate estimation are developed including the dose-rate conversion factors, shape correction for gamma-ray dose and decay of ~(226)Ra. Although development of the techniques for ESR dating of barite has been completed, further comparative studies with other dating techniques such as U-Th and ~(226)Ra-~(210)Pb dating are necessary for the technique to be widely used.