Formation and growth rate mechanism of the oceanic ferromanganese nodules

Two models of a deepwater ferromanganese nodules formation were presented and analyzed: the model with exhaustible and inexhaustible sources of Mn. The models are presented in a form of formulas for calculation that enables one to investigate functional dependencies between growth rate, age and size of the nodules. A notion of the diffusion cell is introduced. The model of microadmixtures accumulation (cosmic dust, radioactive isotopes, etc.) during nodules growth is also considered. The experimental results of the determination of the "cosmic" He concentration in the nodules transported by cosmic dust are presented. The model construction and experimental data results are compared. The preference is given to the model with inexhaustible source of Mn. The problems of ferromanganese nodules and Mn sources are discussed on the basis of diffusion cell concept.