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A note on the chemistry of seawater in the range 350°-500°C

January 1, 1983

The chemistry of seawater at conditions of 350° to 500°C, 220 to 1000 bars (22 to 100 MPa) is controlled by reactions involving magnesium hydroxide sulfate (MHSH) and anhydrite. During progressive heating from 350° to 500°C at 1000 bars (100 MPa), MHSH with a  ratio of 1.25 is formed via precipitation from solution and via reaction of solution with pre-existing anhydrite. During adiabatic expansion the MHSH extracts additional SO4 from seawater and converts to a stoichiometry in which . These reactions control and greatly change the concentrations of Ca, Mg, SO4 in solution and produce significant ionizable hydrogen, attaining 11.7 mmoles kg−1 at maximum conditions.

Publication Year 1983
Title A note on the chemistry of seawater in the range 350°-500°C
DOI 10.1016/0016-7037(83)90098-4
Authors James L. Bischoff, Robert J. Rosenbauer
Publication Type Article
Publication Subtype Journal Article
Series Title Geochimica et Cosmochimica Acta
Index ID 70011662
Record Source USGS Publications Warehouse
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