The dividing line between where calcium carbonate dissolves & accumulate in the ocean is called?

Question

The dividing line between where calcium carbonate dissolves & accumulate in the ocean is called?

Answer 1

It is known as the CCD, or Calcite Compensation Depth.

The actual depth is controlled by several factors, ocean pH, temperature and pressure.  It is deepest at the equator, and shallower near the poles.

Above this level, it is possible for Calcite (CaCO3) to come out of solution, be it as microscopic skeletons, coral reefs or inorganic, fine-grained calcite.  Below this depth Calcite is unstable, and will dissolve into the ocean.