BETA-PARTICLE COUNTING OF SEDIMENTS FROM LAC-DU-BOUCHET AND MEERFELDER-MAAR

A plastic scintillator system for beta particle counting, with automat ic sample changer, has been employed to determine the depth dependence of radioactivity at approx. 2 cm intervals along a 6.5 m sediment cor e from Lac du Bouchet in France. The reliability and reproducibility o f measurements from the system are assessed. The data are compared wit h detailed alpha particle measurements made previously on the same sam ples as used in the present work and with an earlier smaller set of be ta activity measurements from a different core from the same lake. Fif ty two out of the 222 samples from the core were also subject to gamma ray spectrometry to aid the discussion. The relative merits of alpha particle counting, beta particle counting and gamma ray spectrometry t o assess the depth dependence of radioactivity in a sediment core are considered. The interpretation of the activity distribution down the L ac du Bouchet core and in some sediment samples from Meerfelder Maar i n Germany is discussed, particularly in relation to possible climatic influence. Copyright (C) 1997 Elsevier Science Ltd