Influence of the bomb-produced (super 14) C on the radiocarbon concentration in the youngest sediments of Lake Gosciaz, central Poland.

Abstract

This work is a study of changes of the radiocarbon concentration in the youngest part of Lake Gosciaz sediments in the calendar time scale during the last 150 years. This period includes the time of the nuclear weapons tests performed in the upper atmosphere in the 1950s, and the 1960s, which caused large release of (super 14) C and (super 137) Cs into the environment. On the basis of this study, the isotope dilution factor for (super 14) C and the exchange time of carbon between the atmosphere and Lake Gosciaz was estimated. The chronology of the upper part of the sediments was constructed using many interdisciplinary investigations. Among them, measurements of (super 137) Cs in the sediment were used. An unexpected discrepancy between the previously constructed time scale and that suggested by (super 137) Cs is observed in one of the cases.