Figure F5. An example of CCD change estimated using percentages vs. CaCO3 mass accumulation rate (MAR) using two sites. Because the change in carbonate weight percent is not equivalent to the mass of CaCO3 dissolved except when CaCO3 is below 50 wt%, the use of percentage data tends to significantly overestimate the depth to the CCD. Changes in MAR between two sites with different depths but the same CaCO3 rain will give the correct CCD.