Influence of the bomb-produced¹⁴C on the radiocarbon concentration in the youngest sediments of Lake GośCia̧ż, Central Poland

This work is a study of changes of the radiocarbon concentration in the youngest part of Lake Gościa̧ż 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 ¹⁴C and ¹³⁷Cs into the environment. On the basis of this study, the isotope dilution factor for ¹⁴C and the exchange time of carbon between the atmosphere and Lake Gościa̧ż was estimated. The chronology of the upper part of the sediments was constructed using many interdisciplinary investigations. Among them, measurements of ¹³⁷Cs in the sediment were used. An unexpected discrepancy between the previously constructed time scale and that suggested by ¹³⁷Cs is observed in one of the cases.