Geochemistry of hydrothermally altered basalts: Deep Sea Drilling Project hole 504B, Leg 83.

Abstract

The alteration of the basalts involves losses of SiO2, CaO and TiO2, decreases in density and gains in MnO, Na2O, CO2, H2O+, S and MgO. Fe is increasingly oxidized and Al2O3 varies. The REE are somewhat mobile, especially LREE and Eu. The chemistry varies because of different water/rock ratios, secondary mineralogy and superposition of greenschist- and zeolite-facies variations.-K.A.R.