Annealing and etching of corals for ESR dating

Laboratory procedures for ESR dating corals were evaluated. In the range 30 to 60 mg, ESR signal intensity is proportional to aliquot weight. Etching of the corals before analysis did not affect the EST signal at g = 2.0007 or the accumulated dose (AD) calculation. Post-irradiation treatments, annealing at 60°C (3d) or 25°C (14d), showed no difference in AD for coral. The ESR dating signal at g = 2.0007 on successive beating (15 min) showed a rapid decrease in intensity at 200°C and a zero signal at 300°C.