Isabelle M. Shapiro Kha C. Phan Amy Gartman 20260520 comma-delimited text data release DOI:10.5066/P13WN2F7 Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey Suggested Citation: Shapiro, I.M., Phan, K.C., and Gartman, A., 2026, Thermogravimetric Analysis of rock samples from the Escanaba Trough (Gorda Ridge): U.S. Geological Survey data release, https://doi.org/10.5066/P13WN2F7. https://doi.org/10.5066/P13WN2F7 This data release contains data collected using a thermogravimetric analyzer (TGA) of rock samples collected from the Escanaba Trough hydrothermal vent field, Gorda Ridge, in the northeast Pacific Ocean. These data were collected in 2022 on expedition TN403 (USGS Field Activity 2022-621-FA). Samples were taken to the USGS Pacific Coastal Marine Science Center for subsampling before being run on the Thermogravimetric analyzer. Temperature ramp under both oxygenated conditions (sample purge gas is air) and deoxygenate conditions (sample purge gas is nitrogen gas) and the corresponding sample weight of samples are provided in this dataset. These data serve to expand the knowledge and statistics for deep ocean marine mineral occurrences and composition within the US Exclusive Economic Zone and global ocean. Additional information about the field activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/services/activity.php?fan=2022-621-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20220524 20260317 ground condition at the time data were collected through when last process step was completed Complete None planned -127.5358 -127.4463 41.0820 40.6957 ISO 19115 Topic Category oceans geoscientificInformation Data Categories for Marine Planning Nonliving Resources Material Resources Mineral Resources Physical/Chemical Features Assessments USGS Thesaurus metallic mineral resources marine geology Marine Realms Information Bank (MRIB) keywords sediment geochemistry mineral resources chemical analysis None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC Global Ocean Mineral Resources mineralogical analysis USGS Metadata Identifier USGS:69c577f0b66b013bc37be791 Geographic Names Information System (GNIS) Pacific Ocean NGA GEOnet Names Server (GNS) Escanaba Trough Gorda Ridge No access constraints 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 Common 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 Mac OSX 11.6.1, Microsoft Excel 16.47.1 for Mac Thermogravimetric analyzer is calibrated to weight and temperature by instrument manufacturers. Each sample was run in triplicate to verify consistency across sample runs. 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. The location of rock samples were determined using ROV Jason's ultra-short baseline (USBL) navigation. Accuracy for this depth is approximately 6-26 meters. A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted. Vertical accuracy was determined with ROV Jason's altimeter, which is accurate to less than 1 m. No formal positional accuracy tests were conducted. Rock samples were collected on the R/V Thomas G. Thompson between May 24, 2022, and June 13, 2022, during the TN403 Escanaba Trough expedition, which was led and staffed by USGS employees. Rocks were collected from the seafloor using the ROV Jason's manipulator arm at water depths between 3192 and 3319 meters. Rock samples were frozen immediately upon recovery from the ROV, stored frozen, and shipped on ice to the USGS Pacific Coastal and Marine Science Center in Santa Cruz, CA. 20220613 In the USGS Pacific Coastal and Marine Science Center Global Seabed Mineral Resources Lab, rock samples were subsampled, freeze dried, and then ground to a powder using a shatterbox and ceramic-lined bowls and ceramic pucks. Ceramic-lined bowls and pucks were cleaned thoroughly with quartz powder and detergents between samples to avoid cross-contamination. 20230824 Powdered samples were sifted to isolate a size fraction of 75 to 150 microns, then loaded into a PerkinElmer Pyris TGA 9 thermogravimetric analysis system. Small aliquots of each sample were run in triplicate with ultra-high purity compressed nitrogen flowing through the chamber, and in triplicate with compressed laboratory air with an in-line filter, with samples being disposed of after each run. Samples were run with pre-programed temperature ramp from 30 to 300 degrees Celsius at either 5, 10, or 15 degrees Celsius per minute. 20250930 results Results from the Thermogravimetric analyses were combined into a comma-delimited text values document (TN403_TGA.csv). results 20260317 Point Point 382070 0.001 0.001 Decimal degrees D_WGS_1984 WGS_1984 6378137.0 298.257222101 TN403_TGA.csv Comma-delimited file containing results from thermogravimetric analyses of bulk marine mineral samples. The accompanying table TN403_Location.csv includes corresponding location and depth information about each sample. Producer defined Sample_name The sample ID for each sample Producer defined The sample ID of each sample. Samples follow a similar pattern of Dive #-rock number-composition-Sample Purge Gas-run number. For example, j2-1418-r03-bulk-n2s1sf is a size fractionated sample (sf) of rock number 3 from Jason 2 dive number J2-1418, with bulk composition, and the first run (s1) using nitrogen gas (n2) as the sample purge gas. Variations from this name scheme are when the sample name is modified with 5deg and 10deg, which show that this sample was run with the temperature ramp of 5 or 10 degrees Celsius per minute instead of the standard 15. Some sample names also include "parta" or "partb" which refer to the original rock subsample taken from a larger rock during sampling. Sample_purge_gas The gas that was in the chamber while the sample was run. Producer defined N2 this sample was run in nitrogen gas producer defined air this sample was run in air. producer defined Rate This is the rate that the temperature increases by, in degrees Celsius per minute producer defined 5 15 Degrees C per min 5 Time This is the time of the run for each sample. producer defined 0.00000 56.98350 minutes 0.00001 Program_Temperature This is the temperature of the chamber. producer defined 30.009 599.992 degrees Celsius 0.001 Sample_Temperature This is the internal temperature of the sample. producer defined 29.232 595.372 degrees Celsius 0.001 Sample_Purge_Flow This is the pressure at which the sample gas entered the chamber. producer defined 16.45 20.03 pounds per square inch (PSI) 0.01 System_Purge_Flow This is the pressure at which the gas not entering the chamber was cycled through the instrument. Where the system purge flow is zero, the flow was not functioning but should not impact the quality of the reported data. producer defined 0.00 40.06 pounds per square inch (PSI) 0.01 Unsubtracted_Weight This is the weight of the sample. producer defined 0.9234 12.4293 mg 0.0001 TN403_Location.csv Comma-delimited file containing longitude, latitude, and depth information for the samples in the associated data file TN403_TGA.csv. Producer defined Sample_name The sample ID for each sample Producer defined The sample ID of each sample. Samples follow a similar pattern of Dive #-rock number-composition-Sample Purge Gas-run number. For example, j2-1418-r03-bulk-n2s1sf is a size fractionated sample (sf) of rock number 3 from Jason 2 dive number J2-1418, with bulk composition, and the first run (s1) using nitrogen gas (n2) as the sample purge gas. Variations from this name scheme are when the sample name is modified with 5deg and 10deg, which show that this sample was run with the temperature ramp of 5 or 10 degrees Celsius per minute instead of the standard 15. Some sample names also include "parta" or "partb" which refer to the original rock subsample taken from a larger rock during sampling. Latitude This is the latitude of the sample. producer defined 40.6957 41.0820 Decimal degrees 0.0001 Longitude This is the longitude of the sample. producer defined -127.5358 -127.4463 Decimal degrees 0.0001 Depth_meters This is the depth of the sample. producer defined 3198 3284 meters 1 This data release includes 2 comma separated values (CSV) data files containing thermogravimetric analyses of bulk marine mineral samples (TN403_TGA.csv) and the associated location information (TN403_Location.csv). The first line of the csv file is a header line. The "Sample_name" field can be used to join the two data files. 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 16.16.17 for Mac File contains table in .csv format No compression applied 1.77 https://doi.org/10.5066/P13WN2F7 Data can be downloaded using the Network_Resource_Name link and scrolling down to the TGA section. None. These data can be viewed with Microsoft Excel or any text reader. 20260520 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