Fig. 3. Dissolution of calcite grains in a sediment bed capped with a dissolving aragonite pteropod.

The pteropod is shown in a white mesh. Color gradients indicate surface calcite dissolution rates. The white lining represents a saturation state with respect to calcite of unity, i.e., a transition from undersaturation to supersaturation with respect to calcite that is caused by the dissolving aragonite pteropod.