The alpha-efficiency of corals and its importance for ESR-dating

摘要

The uncertainty in an ESR age results almost completely from the error in the evaluation of the annual dose. In the case of corals, alpha -efficiency has a high influence on D-E (Paleodose). The published k(alpha)-values vary from 0.05 to 0.2, so the correct determination of k(alpha) is crucial. In this experiment, based on direct irradiation with an Am-241-source, we used seven samples (20 aliquots for each sample) with different ages. The first aim was to improve the measurement conditions to reach a reliable data base for the alpha -efficiency calculation and the second was the question of age dependency of k(alpha). With respect to the results of our experiments we propose an alpha -efficiency value for corals of 0.06-0.07 which leads to younger ages of about 7-10% less than with the k(alpha) factor of 0.05 we used in previous studies. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 13]