The experimental determination of equilibrium Si isotope fractionation factors among H4SiO4 o, H3SiO4 − and amorphous silica (SiO2·0.32 H2O) at 25 and 75 °C using the three-isotope method
The accurate interpretation of Si isotope signatures in natural systems requires knowledge of the equilibrium isotope fractionation between Si-bearing solids and the dominant Si-bearing aqueous species. Aqueous silicon speciation is dominated by silicic acid (H4SiO4 o) in most natural aqueous fluids at pH < 8.5, but forms H3SiO4 −, H2SiO4 2−, and polymeric Si species in more alkaline fluids. In th
