Oxygen isotope fractionation between synthetic aragonite and water: Influence of temperature and Mg2+ concentration

Aragonite was precipitated in the laboratory at 0, 5, 10, 25, and 40°C to determine the temperature dependence of the equilibrium oxygen isotope fractionation between aragonite and water. Forced CO2 degassing, passive CO2 degassing, and constant addition methods were employed to precipitate aragonite from supersaturated solutions, but the resulting aragonite–water oxygen isotope fractionation was independent of the precipitation method. In …