Uranium in marine basalts: Concentration, distribution and implications

Abstract

The uranium content of glass from chilled margins of oceanic tholeiitic basalt flows is generally ≤0.1ppm, even for old samples with highly altered crystalline interiors. Such low values represent the original whole rock concentrations, although subsequent to eruption low-temperature weathering has added uranium, and other elements, to the crystalline portions of these basalts. Consideration of the K/U ratios of altered samples suggests that basalt weathering may provide the major oceanic sink for these two elements.