CaCO3 content in ocean surface sediments

Taken at face value, these results indicate that depth of the calcite saturation horizon and hence also the product of the Ca2+ and [CO3]2- concentrations have remained nearly constant.

In turn, this suggests that the ratio of calcite production to ingredient supply has not undergone large changes. In this paper, the method used to reconstruct the temporal fluctuations and interocean differences in the depth of the calcite saturation horizon is scrutinized. The basis for my concern is that offset between the depth of the calcite saturation horizon and the depth where dissolution reduces the CaCO3 content to 20% (i.e., the CCD) can vary by a half kilometer or so depending on the rain rates of CaCO3 and non CaCO3.