Sediment dating with 137Cs
This technique exploits the injection of radioisotopes into the atmosphere, which occurred during atmospheric nuclear testing, mainly in the late 1950s and mid 1960s. It uses this injection as a marker to identify soil and sediment particles laid down at that time.
137Cs is analysed by directly counting the sediment in a high resolution low background germanium gamma detector. These measurements enable identification of the mid-1960’s bomb fallout maximum, a marker that can be used alone or to corroborate ages derived from 210Pb.