Mechanisms for Calcite Dissolution on the Sea Floor.

摘要

Arguments in support of the hypothesis that the major dissolution of CaCO3 in the deep sea takes place within a few millimeters of the water-sediment interface are presented. Three models for the dissolution of CaCO3 are considered: the stagnant boundary film model, and the constant and variable resaturation time models. Assuming that the diffusive flux of carbonate radical is equal to that of total carbon dioxide out of sediment, the validity of each model is tested using the calcium carbonate distribution in sediments observed in the Rio Grande Rise area. The stagnant boundary film model fails to adequately represent the data. The constant resaturation time model fits the data satisfactorily, and gives a characteristic calcite resaturation time consistent with the experimental value of 7 minutes.