Ferromanganese oxide crusts are members of a family of manganese and iron oxide precipitates that are widely distributed in the lithosphere. They can be defined as encrustations forming largely on hard substrates that are at least periodically kept free from detrital sedimentation by strong currents, steep slopes, or both. In near-shore or hydrothermal environments where metal supply is much greater than it is in most of the open ocean, crusts may also form on soft sediments. The pioneering German "Midpac I" investigation of cobalt-rich ferromanganese oxide phases in the Central Pacific in 1981 lead to the development of interest in the processes causing cobalt enrichment in seamount "nodules" and crusts and the recognition of the possible resources in cobalt rich crusts within 200 miles of U.S. and territorial coasts. Crusts pose specific problems because unlike nodules they tend to occur in a highly localized manner. They also generally adhere to hard substrates in such a fashion that they cannot easily be separated from underlying substrate during recovery; And finally, their elemental composition varies from nearly pure manganese or iron oxides (both frequently hydrothermal in origin) to the fairly consistent admixtures that characterize cobalt-rich crusts. The main effort of this study has been to collect and evaluate all available samples and information, to analyze new samples by means of well-controlled and defined analytical procedures, and to present all information through the end of 1987 in a consistent and complete form. As a part of this effort, all data were classified and normalized for mapping purposes so that information from diverse sources could be compared over larger geographic areas. For resolving the difficult problem of contamination and water treatment a basic procedure was chosen that normalizes data to a constant Fe+Mn content in order to draw ocean wide conclusions on the distribution and chemical properties of ferromanganese crusts. Investigators who wish to use other means of dealing with the comparability problem have the complete basic information in the published database to create their own models.

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.--------------------------------------------------------------------APPENDIX A - USGS STATION DATA------------------Ling, T H; Manheim, Frank T (2023): Annotated record of the detailed examination of Mn deposits. PANGAEA, doi:10.1594/PANGAEA.962514Ling, T H; Manheim, Frank T (2023): Annotated record of the detailed examination of Mn deposits from MIDPAC-2a (SO33) expedition stations. PANGAEA, doi:10.1594/PANGAEA.961878Ling, T H; Manheim, Frank T (2023): Annotated record of the detailed examination of Mn deposits from MIDPAC-2b (SO37) expedition stations. PANGAEA, doi:10.1594/PANGAEA.961883Ling, T H; Manheim, Frank T (2023): Annotated record of the detailed examination of Mn deposits from KK84-04-28 and KK84-08-24 expeditions stations. PANGAEA, doi:10.1594/PANGAEA.962202NOTE: Parts of the Appendix A Samples data table have been published on PANGAEA as separate tables when the corresponding stations from non-USGS expeditions were used exclusively in one of the geochemical data tables which are part Appendix C (Ex: Table 5a - MIDPAC-2a (SO33) expedition)--------------------------------------------------------------------APPENDIX C - CHEMICAL DATA------------------Table 1 - USGS Reston Laboratory dataAruscavage, P J; Brown, F M; Kirschenbaum, H; Root, D M: Ferromanganese crusts and nodules chemical analyses from the USGS Reston analytical laboratories. PANGAEA, doi:10.1594/PANGAEA.962509--Table 2 - USGS Woods Hole Laboratory dataCommeau, J A; Manheim, Frank T; Ling, T H: Ferromanganese crusts and nodules chemical analyses from the USGS Woods Hole analytical laboratories. PANGAEA, doi:10.1594/PANGAEA.962519--Table 3 - Bureau of Mines Avondale dataUS Bureau of Mines, Avondale, Maryland (2023): Ferromanganese crusts and nodules chemical analyses from cruises KK84 (R/V Kana Keoki) and L583HW (R/V S.P. Lee). PANGAEA, doi:10.1594/PANGAEA.962527--Table 4 - German Geological Survey dataCommeau, J A; Manheim, Frank T (2023): Ferromanganese nodules and crusts chemical analysis of samples from cruise L583HW (R/V S.P. Lee) using X-ray. PANGAEA, doi:10.1594/PANGAEA.962528Marchig, Vesna; Gundlach, Heinrich (2023): Ferromanganese nodules and crusts chemical analysis of BGR samples from the Midpac '81 expedition with R/V Sonne (SO18). PANGAEA, doi:10.1594/PANGAEA.962529Halbach, Peter; Puteanus, Doris (2023): Ferromanganese nodules and crusts chemical analysis of TUVLZ samples from the Midpac '81 expedition with R/V Sonne (SO18). PANGAEA, doi:10.1594/PANGAEA.962530--Table 5 - Portaspec shipboard dataLing, T H; Commeau, J A (2023): PORTASPEC shipboard determined chemical composition of ferromanganese crusts for L9-84-CP expedition (R/V S.P. Lee). PANGAEA, doi:10.1594/PANGAEA.962227Manheim, Frank T; Ling, T H: Shipboard ferromanganese nodules and crusts chemical analysis of samples from cruise L583HW (R/V S.P. Lee) using a Portaspec X-ray fluorescence instruments. PANGAEA, doi:10.1594/PANGAEA.962531--Table 5a - Midpac 2a and 2b dataHalbach, Peter; Puteanus, Doris (2023): Chemical composition of ferromanganese crusts from MIDPAC cruise 2a (SO33) (R/V Sonne). PANGAEA, doi:10.1594/PANGAEA.961880Halbach, Peter; Puteanus, Doris (2023): Chemical composition of ferromanganese crusts from MIDPAC cruise 2b (SO37) (R/V Sonne). PANGAEA, doi:10.1594/PANGAEA.961885--Table 6 - Japanese (A.Usui) dataUsui, Akira; Terashima, Shigeru (2023): Bulk chemical composition of pelagic sediment samples from the Central Pacific Basin, GH 79-1 detailed survey area. PANGAEA, doi:10.1594/PANGAEA.962209--Table 7 - Analytical Services (cruise KK84) dataAnalytical Services Company (2023): Ferromanganese crust chemical analyses. Samples from KK84 cruise from R/V Kana Keoki. PANGAEA, doi:10.1594/PANGAEA.962203--Table 8 Aplin thesis data - Major and Minor analysesAplin, Andrew C; Cronan, David S (2022): Chemical composition of manganese crusts along the Line Islands archipelago for major and trace elements. PANGAEA, doi:10.1594/PANGAEA.945241--Table 8a - Aplin thesis data - REEAplin, Andrew C (2023): Chemical concentrations of REE and Pb for Mn crusts from the Line Islands Archipelago. PANGAEA, doi:10.1594/PANGAEA.962204--Table 9 and Table 10 - SNDB major, minor analyses and trace analysesFrazer, Jane Z; Fisk, Mary B (2023): Ferromanganese nodules and crusts chemical analyses from SIO outside of the International Decade of Ocean Exploration (IDOE) program. PANGAEA, doi:10.1594/PANGAEA.961015Okada, Akihiko; Minakuchi, Tadayuki; Shima, Makoto (2023): Bulk chemical composition of manganese deposits fom the Pacific and Indian oceans. PANGAEA, doi:10.1594/PANGAEA.961781Okada, Akihiko; Minakuchi, Tadayuki; Shima, Makoto (2023): Chemical composition in Pb and Zn of manganese deposits from the Pacific Ocean. PANGAEA, doi:10.1594/PANGAEA.961782NOTE: The data tables Table 9 and Table 10 of the original USGS Report have been merged together. Furthermore, the data extracted by the authors from the Scripps Institute of Oceanography Nodule Data Bank (SNDB) which were already published on PANGAEA as part of the NGDC-MMS data bank have been ommited--Table 11 - NGDC data - major and minor analysesIn order to build this data table, the authors have extracted geochemical measurements from a selection of tables already published on PANGAEA under the NOAA-MMS project--Table 12 - Dillard and Crowther (1984), Exon (1982)Dillard, J G; Crowther, D L; Calvert, Stephen E (2023): Bulk chemical composition of manganese deposits fom the Pacific Ocean. PANGAEA, doi:10.1594/PANGAEA.961730Exon, Neville F (2023): Chemical composition of manganese deposits from cruise WS-79(1) in the the Samoan region, Southwest Pacific ocean. PANGAEA, doi:10.1594/PANGAEA.961754Glasby, Geoffrey P; Meylan, Maurice A (2023): Chemical composition of manganese crusts fom the Manihiki Plateau area. PANGAEA, doi:10.1594/PANGAEA.961759Greene, H Gary; Exon, Neville F (2023): Chemical composition of manganese crusts fom the Southwest Pacific Ocean. PANGAEA, doi:10.1594/PANGAEA.961703--Table 13 Volkov (1976), Dymond and others (1984)Volkov, Igor I; Fomina, Lidiya S; Yagodinskaya, T A (1976): (Table 1) Chemical composition of Fe-Mn nodules, crusts and host sediments at the section from the Wake Atoll to the Hawaiian Islands. PANGAEA, doi:10.1594/PANGAEA.744509Dymond, Jack R; Lyle, Mitchell W; Finney, Bruce P; Piper, David Z; Murphy, Kim; Conard, Roberta; Pisias, Nicklas G (2023): MANOP Site H manganese nodules and crusts chemical composition determined by atomic absorption spectrometry (AAS). PANGAEA, doi:10.1594/PANGAEA.961504Dymond, Jack R; Lyle, Mitchell W; Finney, Bruce P; Piper, David Z; Murphy, Kim; Conard, Roberta; Pisias, Nicklas G (2023): MANOP Site H manganese nodules and crusts chemical composition determined by instrumental neutron activation (INAA). PANGAEA, doi:10.1594/PANGAEA.961505Dymond, Jack R; Lyle, Mitchell W; Finney, Bruce P; Piper, David Z; Murphy, Kim; Conard, Roberta; Pisias, Nicklas G (2023): MANOP Sites S and R manganese nodules chemical composition determined by atomic absorption spectrometry (AAS). PANGAEA, doi:10.1594/PANGAEA.961506NOTE: Regarding the geochemical data from Volkov (1976), the author have only reproduced the values for event (station) DM9-11--Table 14 Goddard and others (1987)Goddard, D A; Thompson, G; Jones, E J W; Okada, H (1987): (Table 3, page 92-93) Chemical composition of bulk ferromanganese oxide deposits from the equatorial zone of the Mid-Atlantic Ridge. PANGAEA, doi:10.1594/PANGAEA.856657--Table 15 Goddard and others (1987)Goddard, D A; Thompson, G; Jones, E J W; Okada, H (1987): (Table 4, page 94) Chemical composition of ferromanganese encrustations from the Equatorial Atlantic. PANGAEA, doi:10.1594/PANGAEA.856658--Table 16 DeCarlo and others (1987)De Carlo, Eric Heinen; McMurtry, Gary M; Kim, Kee Hyun (2023): Chemical constituents of selected ferromanganese crust samples from the Hawaiian Archipelago. PANGAEA, doi:10.1594/PANGAEA.953854--Table 17 DeCarlo and others (1987)De Carlo, Eric Heinen; Fraley, C M (2023): Bulk chemical analysis of manganese crusts from the Equatorial Pacific Ocean. PANGAEA, doi:10.1594/PANGAEA.961663--Table 18 Hein and others (1987) OF87-281Hein, James R; Fleishman, C L; Morgenson, Lisa A; Bloomer, Sherman H; Stern, Robert J (2023): Chemical composition of ferromanganese deposits from the Mariana and Volcano volcanic arcs. PANGAEA, doi:10.1594/PANGAEA.961645