Manheim(1986)による〔『Marine cobalt resources』(600p)から〕


Ferromanganese oxides in theopen oceans are more enriched in cobalt than any other widely distributed sediments or rocks. Concentrations of cobalt exceed 1 percent in ferromanganese crusts on seamounts, ocean ridges, and other raised areas of the ocean. The cobalt-rich crusts may be the slowest growing of any earth material, accumulating one molecular layer every 1 to 3 months. Attention has been drawn to crusts as potential resources because they contain cobalt, manganese, and platinum, three of the four priority strategic metals for the United States. moreover, unlike abyssal nodules, whose recovery is complicated by their dominant location in international waters, some of the most cobalt-rich crusts occur within the exclusive economic zone of the United States and other nations. Environmental impact statements for crust exploitation are under current development by the Department of the Interior.』

Distribution of cobalt in the Earth's crust and in ores
Cobalt in the ocean ferromanganese nodules and crusts
Chemical data banks
Cobalt in nodules and crusts
Rates of accumulation
Economic and strategic background for cobalt
Potential of marine cobalt resources
References and notes