We present a novel determination of the dissolution kinetics of inorganic calcite in seawater. We dissolved C-13-labeled calcite in unlabeled seawater, and traced the evolving delta C-13 composition of the fluid over time to establish dissolution rates. This method provides sensitive determinations of dissolution rate, which we couple with tight constraints on both seawater saturation state and surface area of the dissolving minerals. We have determined dissolution rates for two different abiotic calcite materials and three different grain sizes. Near-equilibrium dissolution rates are highly nonlinear, and are well normalized by geometric surface area, giving an empirical dissolution rate dependence on saturation state (Omega) of:
展开▼
