Ferromanganese oxide deposits

Cronan D. S. (1976b) Manganese nodules and other ferromanganese oxide deposits, chap. 28. In Chemical Oceanography, 2nd edn. (eds. J. P. Riley and R. Chester). Academic Press, London, vol. 5, pp. 217-263. 

Manganese nodules, together with micronodules and encrustations, are ferromanganese oxide deposits which contain variable amounts of other elements... 

Table 1 Average abundances of elements in ferromanganese oxide deposits...

As most nuclei are subject to replacement with time, old nodules have sometimes completely replaced their nuclei and have fractured, thus providing abundant nodule fragments to serve as fresh nuclei for ferromanganese oxide deposition. In this way, given sufficient time, areas which initially contained only limited nuclei may become covered with nodules. 

Karpoff, A. M., Peterschmitt, I. Hoffert, M. 1980. Mineralogy and Geochemistry of Sedimentary Deposits on Emperor Seamounts, Sites 430, 431 and 432 Authigenesis of Silicates, Phosphates and Ferromanganese Oxides. Initial Reports Deep Sea Drilling Project, LV, US Gov. Print. Office, 463-489. 

Ferromanganese crusts consist of iron and manganese oxide layers deposited on hard-rock substrates of seamounts, ridges, and plateaus, in areas where the ocean currents have been strong enough to keep the hard-rock substrates free of other sediment deposits for at least millions of years. Hein et al. (2000) summarized the distribution and geochemistry of ferromanganese... 

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