Abstract: Abstract Buried sediments receive about 53% of their annual dose of ionising radiation from radionuclides in the uranium and thorium decay chains. In luminescence dating of sediment samples, it is usually assumed that the dose rate does not change over the period of burial, implying that the uranium and thorium decay series are in secular equilibrium. For the 232 Th decay chain there is little literature available on the equilibrium conditions in sediments, but given the short half-lives of the longer-lived daughters in the series, 228 Ra (5.75...
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Topics: 
Geochemistry