There are several theories for how seabed nodules form.They are not geological in origin, unlike the formation such metals on land. First, a biological process (such as the remnant of a shark tooth) falls to the ocean floor.This forms the basis around which microorganisms gather. These microorganisms have developed processes over millions of years to extract trace metals from the seawater.These biological processes catalyze the chemistry needed to form and grow seabed nodules. Seabed Nodules grow at an incredibly slow rate of 10 millimeters every million years. Once these nodules are removed, they will never reoccur ... (full story)