Ferromanganese crusts in the world's oceans may serve as potential sources of metals, such as cobalt and magnesium, valuable to civilian and military industry; these are metals that the United States would otherwise be dependent on foreign sources. Unlike abyssal ferromanganese nodules, which form in areas of low disturbance and high sediment accumulation, ferromanganese crusts have been found to contain three to five times more cobalt than abyssal ferromanganese nodules and can be found on harder, steeper substrates than abyssal plains, which can be too steep for permanent sediment accumulation. Ferromanganese crusts have also been documented on seamounts and plateaus within the U.S. exclusive economic zone in the Pacific and Atlantic Oceans and are therefore of strategic importance to the United States Government as well as to civilian mining and metallurgical industries. A database containing ferromanganese crust occurrences throughout the world's oceans was assembled from published and unpublished sources to provide data gathering and analytical information for these samples. These data provide the digital formatted locations of the sample locations of the U.S. Geological Survey and Scripps Institution Nodule Data Bank (SNDB) from appendixes A and B. These locations from 1986 and earlier are also represented on the maps of Lane and others (1986). > Manheim, F.T., Lane-Bostwick, C.M., 1989, Chemical composition of ferromanganese crusts in the world ocean: A review and comprehensive database: U.S. Geological Survey Open-File Report 89-020, http://pubs.usgs.gov/of/1989/0020/