Radium, thorium, and uranium isotopes in the interstitial water from the Pacific Ocean sediment

Abstract

The Ra, Th, and U isotopic concentrations were determined in the interstitial water expressed from a deep sea core of the eastern equatorial Pacific. The isotopes ²²⁶Ra, ²²⁸Ra, ²³⁰Th, and ²²⁸Th are higher by 1 to 3 orders of magnitude than their concentrations in seawater. Radium release from sedimentary phases with migration into the water column is indicated. The results are also compatible with the excess ²²⁸Th (relative to ²³²Th) found in authigenic deep sea minerals.