231Pa dating of deep-sea cores via 227Th counting

摘要: A simple procedure for simultaneous Io and 231Pa dating of deep-sea sediments is described. The content determined from the specific activity its grand-daughter 227Th. Fast thorium (and uranium) separation carried out with a newly developed using ion-exchangers Aliquat-336 TTA. was applied cores Vema 18–258, Valdivia 10127 10141 North South Pacific. In case core 18–258 our results confirm previous data T.L. Ku. For sedimentation rates respectively 2.7 3.2 mm/1000 years were calculated decrease excess activities. different in section above below 18 cm found (0–18 cm: 3.9 (Io) 5 (231Pa); 18–37 20 (Io 231Pa)). These findings give proof that 227Th sediment essentially radioactive equilibrium 231Pa. via counting simultaneously to suggested.