Katlin Bowman Adamczyk Amy Gartman Jaycee Favela 20260623 comma-delimited text data release doi:10.5066/P149BW9Z Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P149BW9Z Katlin Bowman Adamczyk Amy Gartman Jaycee Favela Kira Mizell Isabelle M. Shapiro Kha C. Phan 2026 data release doi:10.5066/P149BW9Z Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey Suggested Citation: Adamczyk, K.B., Gartman, A., Favela, J., Mizell, K., Shapiro, I.M., and Phan, K.C., 2026, Abundance and geochemistry of abyssal ferromanganese nodules and ferromanganese coated rocks from the Samoa Basin (2026-604-FA): U.S. Geological Survey data release, https://doi.org/10.5066/P149BW9Z. https://doi.org/10.5066/P149BW9Z Ferromanganese nodules and other ferromanganese coated rocks were collected using a box core from the Samoa Basin, during USGS field activity 2026-604-FA. Ferromanganese nodules and ferromanganese coated rocks were collected by box core and total mass was determined using a digital crane scale calibrated with National Institute of Standards and Technology certified calibration weights. These data serve to expand the knowledge and statistics for seabed mineral occurrences and composition within the global ocean. The expedition 2026-604-FA was the third leg of the National Oceanic and Atmospheric Administration's American Samoa Abyssal Mapping effort, OPR-T900-KR-26. The USGS effort was supported in part by Interagency Agreement M20PG00028 between the USGS and the Bureau of Ocean and Energy Management. Additional information about the field activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2026-604-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20260413 20260428 ground condition at time data were collected Complete None planned -167.86053 -165.61942 -13.17100 -17.03570 ISO 19115 Topic Category oceans geoscientificInformation Data Categories for Marine Planning Nonliving Resources Material Resources Mineral Resources Physical/Chemical Features Assessments USGS Thesaurus box coring marine geology rocks and deposits mineral deposits metallic mineral resources Marine Realms Information Bank (MRIB) keywords seabed sediment mineral resources field observation box coring marine geology None U.S. Geological Survey USGS Geology, Energy, and Minerals Mission Area GEMMA Pacific Coastal and Marine Science Center PCMSC Global Ocean Mineral Resources USGS Metadata Identifier USGS:6a1769d8b66b01122d755be6 Geographic Names Information System (GNIS) South Pacific Ocean Territory of American Samoa NGA GEOnet Names Server (GNS) Samoa Basin No access constraint USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. These data are marked with a Creative Commons CC0 1.0 Universal License. Please recognize and acknowledge the U.S. Geological Survey as the originator of the dataset and in products derived from these data. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov The expedition 2026-604-FA was the third leg of the National Oceanic and Atmospheric Administration's American Samoa Abyssal Mapping effort, OPR-T900-KR-26. The USGS effort was supported in part by Interagency Agreement M20PG00028 between the USGS and the Bureau of Ocean and Energy Management. Microsoft Windows 11 Enterprise, Microsoft Excel 15 Calibration weights (0.200, 0.500, 1.000 kilograms) certified by the National Institute of Standards and Technology were used to calibrate the digital crane scale on at least a weekly basis. No formal logical accuracy tests were conducted. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. A Kongsberg Acoustic Positioning Operator Station (APOS) calibration was completed using the ship's GPS data and a fixed seabed transponder. The standard deviation of the transponder position was N1.26 meters and E1.34 meters. A Kongsberg Acoustic Positioning Operator Station (APOS) calibration was completed using the ship's GPS data and a fixed seabed transponder. The standard deviation of the transponder depth was 1.31 meters. National Oceanic and Atmospheric Administration (NOAA) 2026 https://console.cloud.google.com/storage/browser/noaa-deep-sea-minerals;tab=objects?prefix=&forceOnObjectsSortingFiltering=false Google Cloud database 20260430 Date that database READ ME file was created. NOAA Seafloor Mapping and Imagery Data Seafloor mapping (ship- and AUV-based) and AUV imagery used to inform box core sample locations National Oceanic and Atmospheric Administration (NOAA) 2026 https://oceanexplorer.noaa.gov/mineral-samples/2026-nv5-american-samoa/ online database 20260428 Date that final image was captured. Box Core Sample Photos Shipboard images of box core samples. 38 box core samples were collected between April 13 and April 28, 2026, during USGS field activity 2026-604-FA. USGS directed the location of box core deployment. Seafloor mapping (ship- and AUV-based) and AUV imagery collected by NOAA in February-April 2026 were used to inform box core sample locations. External personnel working for organizations contracted through NOAA were responsible for deployment and recovery of an Ocean Instruments BX-750 Box Corer at each sample location; an AML Oceanographic CTD (conductivity temperature depth) and Kongsberg MiniS 37 -40V Ti transponder were mounted to the frame of the box core to determine the depth and location of each seafloor sample. Personnel contracted through NOAA collected USBL location data. USGS was responsible for all sample processing after the box core was recovered. NOAA Seafloor Mapping and Imagery Data 20260428 Top water was removed from the box core using a peristaltic pump and tubing, then a photograph of the box core surface was captured. All box core sample photos are available online through NOAA at https://oceanexplorer.noaa.gov/mineral-samples/2026-nv5-american-samoa/. Box Core Sample Photos 20260428 Surface ferromanganese nodules and ferromanganese coated rocks were immediately removed from the box core after top water removal and box core surface photography, then transferred to a laboratory van. Ferromanganese nodules and ferromanganese coated rocks along the edges of the box core that appeared to have been pushed down by the spade were included in the surface mass. Excess sediment was removed by rinsing the nodules with filtered seawater. The wet mass of surface ferromanganese nodules and ferromanganese coated rocks was determined using a RoMech digital crane scale that was calibrated with NIST certified weights and had a lower detection limit of 0.5 kilograms. 20260428 Buried ferromanganese nodules were recovered from four box cores (BX03, BX32, BX33, BX36) during subcoring (collection of push cores), push core processing, or by hand-searching the remaining sediment after subcores were removed. The sediment depth in these four box core samples ranged from 34-40 centimeters. Excess sediment was removed from buried nodules by rinsing with freshwater or filtered seawater. The wet mass of buried nodules was determined using a RoMech digital crane scale that was calibrated with NIST certified weights and had a lower detection limit of 0.5 kilograms. The wet mass of buried nodules was added to the wet mass of surface nodules to calculate the whole box mass of ferromanganese nodules and coated rocks. 20260428 The surface abundance and whole box abundance were calculated by dividing the measured surface mass and whole box mass of each box core by the surface area of the box core sample (0.5625 square meters). 20260430 The location of the box core on the seafloor was determined from the USBL location on bottom where available (BX38), from the deepest USBL location (BX06 and BX28) or by calculating the midpoint latitude and longitude of the deepest measured USBL coordinates from the up and down cast of each box core. Only downcast USBL data was available for BX06 and only upcast USBL data was available for BX28. Samples BX 01-05, 17, and 25 did not have functioning USBL data, indicated by -9999 in the data table. The water depth of each box core sample was determined by extracting the deepest measured depth value from the box core CTD data and correcting this depth for the mounted height of the CTD (2 meters from the base of the box core). 20260527 Box core sample information (date and time on bottom, station name, sample location and depth) and surface and total abundance were combined into a comma-delimited text values document (2026-604-FA_NoduleAbundance.csv). 20260527 Point Point 38 0.00001 0.00001 Decimal degrees D_WGS_1984 WGS_1984 6378137.0 298.2572223563 local sea surface 1 meters Attribute values 2026-604-FA_NoduleAbundance.csv table containing box core sample ID, date and time on bottom, location and water depth, station, surface abundance and whole box abundance of ferromanganese nodules and ferromanganese coated rocks. Producer defined Cruise_ID Lists the alphanumeric cruise identifier for the expedition during which the sample was collected Producer defined 2026-604-FA is the cruise ID and a U.S. Geological Survey field activity number Core_ID The sample ID for each box core sample Producer defined Unique sample identifier Node Lists the alphanumeric node near which the box core sample was collected. Node locations and names were determined as part of NOAA’s American Samoa Abyssal Mapping effort, OPR-T900-KR-26, and correspond to AUV focused grid surveys; they are given to facilitate referencing between co-located datasets. Mapping and seafloor image data from each node is included in the NOAA Seafloor Mapping and Imagery Data online database. Producer defined Unique location identifier Date_On_Bottom Date that the box core made contact with the seafloor in Coordinated Universal Time (UTC). producer defined 4/13/2026 4/28/2026 Date in MM/DD/YYYY format Time_On_Bottom Time that the box core made contact with the seafloor in Coordinated Universal Time (UTC) in 24-hour time format. producer defined 0:16 23:13 Time in HH:MM format Surface_Abundance The abundance of ferromanganese nodules and/or ferromanganese coated rocks collected from the surface of the box core in units of kilograms per square meter. Values of -9999 indicate that no analysis was performed; this occurred when the box core did not recover a seafloor sample. Values of -8888 indicate that the measurement was below the detection limit of 0.5 kilograms. Values of 0.0 indicate that no ferromanganese nodules or ferromanganese coated rocks were present in the box core sample. producer defined 0.0 18.5 kilograms per square meter .1 Whole_Box_Abundance The abundance of ferromanganese nodules and/or ferromanganese coated rocks collected from the whole box core in units of kilograms per square meter. This value includes the mass of buried ferromanganese nodules and/or ferromanganese coated rocks when present. Values of -9999 indicate that no analysis was performed; this occurred when the box core did not recover a seafloor sample. Values of -8888 indicate that the measurement was below the detection limit of 0.5 kilograms. Values of 0.0 indicate that no ferromanganese nodules or ferromanganese coated rocks were present on the surface of the box core. producer defined 0.0 21.0 kilograms per square meter .01 Latitude_USBL Latitude of the box core at the listed date and time on bottom, determined by a USBL system. Values of -9999 indicate that data are not available. producer defined -17.035401 -13.170653 decimal degrees .000001 Longitude_USBL Longitude of the box core at the listed date and time on bottom, determined by a USBL system. Values of -9999 indicate that data are not available. producer defined -167.861665 -165.620218 decimal degrees .000001 Latitude_Ship Latitude of the surface vessel when the box core made contact with the seafloor. producer defined -17.03570 -13.17100 decimal degrees .00001 Longitude_Ship Longitude of the surface vessel when the box core made contact with the seafloor. producer defined -167.86053 -165.61942 decimal degrees .00001 Water_Depth Water depth where the box core sample was collected. This depth was determined using a CTD mounted to the box core frame. producer defined 5184 5787 meters 1 This dataset contains one comma separated values (CSV) file describing box core sample information collected during USGS field activity 2026-604-FA (2026-604-FA_NoduleAbundance.csv). The first line of the csv file is a header line. Geochemical data are included in a separate part of this data release. U.S. Geological Survey U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov These data are available in .csv format contained in a single file accompanied by CSDGM FGDC-compliant metadata. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. comma-delimited text Microsoft Excel 15 File contains table in .csv format No compression applied 0.00357 https://doi.org/10.5066/P149BW9Z Data can be downloaded using the Network_Resource_Name links and scrolling down to the Abundance of ferromanganese nodules and ferromanganese coated rocks dataset. None. These data can be viewed with Microsoft Excel or any text reader. 20260623 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998