Radioactive disequilibrium in altered mid-oceanic basalts

M.P. Bacon

doi:10.1016/0012-821x(78)90200-5

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Radioactive disequilibrium in altered mid-oceanic basalts

M.P. Bacon

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Abstract

A young (<1 m.y.) tholeiitic basalt dredged from the Mid-Atlantic Ridge displays a 234 U excess and a 230 Th deficiency that have resulted from the addition of seawater uranium during weathering at seafloor temperatures. Two older samples, though they acquired substantial amounts of uranium from seawater, are depleted in 234 U, indicating preferential leaching of this isotope. Hydrothermally altered samples suggest that some uranium loss may have occurred. Possible isotopic effects of preferential 234 U leaching, however, are obscured by secondary addition of seawater uranium at lower temperatures.

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M.P. Bacon. 1978. Radioactive disequilibrium in altered mid-oceanic basalts. https://doi.org/10.1016/0012-821x(78)90200-5

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