Study of the effect of a thermal treatment on the DE determination in ESR dating of speleothems

In order to determine the better analytical way to obtain reproducible DE values from these three ESR signals, successive additional annealing treatments ranging from 60-300 °C were performed on several samples of a stalagmitic floor from the Mousterian site of the Caverna delle Fate (Liguria, Italy), also dated by U-series between 90 and130 ka. The results confirm that DE values can be obtained from h3 and BL signals without annealing, while the h1 signal requires a thermal pre-treatment, to obtain the maximum intensity of this line. Then, on our samples, the DE values derived for the three lines are equivalent. It gives, hence, the opportunity to obtain data when the g=2.0007 line cannot be used.