The areas of the seafloor containing these nodules have some of the lowest sedimentation rates in the world ocean — this is why these deposits are exposed more

The areas of the seafloor containing these nodules have some of the lowest sedimentation rates in the world ocean — this is why these deposits are exposed more or less at the sediment-water interface, and not buried in terrigenous sediment derived from land or surface pelagic calcifiers (plankton). Significant time in a geologically stable setting is also required for these oxides to form — their rate of formation is extremely slow.