Study on absolute age determination for inland clastic sediments, especially on dosimetric dating

Consequently, the following topics and comments are pointed out: (1) Quartz bearing sediments would be most suitable for the dosimetric dating based on a mechanism of sun-light breaching (time zeroing) as well as that of crystallization. (2) Amorphous specimens such as volcanic glass and diatomite could be dated by using low power ESR measurement at liquid nitrogen temperature, if saturation were avoidable during irradiation. (3) High dose rate irradiation over 4.5 Gray/min would change susceptibility and/or sensitivity especially in cases of most sample older than 100Ka. (4) Irradiation by means of lineac electron beam (or X-ray) source is very useful because of its high accuracy of dose control. (5) Precise gamma-ray detector can be put to practical use for direct measurement of dose-rate as well as quantitative analysis for natural radioactive elements (U,Th,K).