OPEN SYSTEM MODEL FOR URANIUM SERIES DATING

Starting from the assumption that all products formed by radioactive decay remain in the sample to be dated until they also decay by nuclear transformation, and that uranium originally migrated into the sample changes with time according to an exponential law, an open system model is formulated. The model is applied to experimental data given by Szabo and Rosholt [2] in an attempt to date marine deposits of southern California by investigating molluscan shells. The present model yields the same age for the first terraces at San Pedro and Santa Monica (78,000 and 80,000 years respectively) in agreement with the age determined for the first terrace of the Island of Barbados. © 1979.