Toward sufficient reduction of radio-impurities for 32Si sediment age dating

This project is focused on developing a geochronology tool enabling age dating of coastal marine sediments in the 100–1000 year age range. The technique employs the 32Si/32P radio-chronometer with an ultra-low-background gas proportional beta detector with a background count rate approaching 10 counts per day (cpd), which will require significant decontamination of radiogenic nuclides present in the original sediment samples. This paper describes the multiple physical and chemical separation methods employed to maintain a high final chemical yield of P while reducing the radiogenic contributions. The final purified 32P samples had, on average 100 ± 7 % chemical yields with no quantifiable gamma emissions present.