Metadata: Identification_Information: Citation: Citation_Information: Originator: Isabelle M. Shapiro Originator: Kha C. Phan Originator: Amy Gartman Publication_Date: 20260520 Title: Thermogravimetric Analysis of rock samples from the Escanaba Trough (Gorda Ridge) Geospatial_Data_Presentation_Form: comma-delimited text Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P13WN2F7 Publication_Information: Publication_Place: Pacific Coastal and Marine Science Center, Santa Cruz, California Publisher: U.S. Geological Survey Other_Citation_Details: 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. Online_Linkage: https://doi.org/10.5066/P13WN2F7 Description: Abstract: 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. Purpose: 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. Supplemental_Information: 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. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20220524 Ending_Date: 20260317 Currentness_Reference: ground condition at the time data were collected through when last process step was completed Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -127.5358 East_Bounding_Coordinate: -127.4463 North_Bounding_Coordinate: 41.0820 South_Bounding_Coordinate: 40.6957 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Data Categories for Marine Planning Theme_Keyword: Nonliving Resources Theme_Keyword: Material Resources Theme_Keyword: Mineral Resources Theme_Keyword: Physical/Chemical Features Theme_Keyword: Assessments Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: metallic mineral resources Theme_Keyword: marine geology Theme: Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords Theme_Keyword: sediment geochemistry Theme_Keyword: mineral resources Theme_Keyword: chemical analysis Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: U.S. Geological Survey Theme_Keyword: USGS Theme_Keyword: Coastal and Marine Hazards and Resources Program Theme_Keyword: CMHRP Theme_Keyword: Pacific Coastal and Marine Science Center Theme_Keyword: PCMSC Theme_Keyword: Global Ocean Mineral Resources Theme_Keyword: mineralogical analysis Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:69c577f0b66b013bc37be791 Place: Place_Keyword_Thesaurus: Geographic Names Information System (GNIS) Place_Keyword: Pacific Ocean Place: Place_Keyword_Thesaurus: NGA GEOnet Names Server (GNS) Place_Keyword: Escanaba Trough Place_Keyword: Gorda Ridge Access_Constraints: No access constraints Use_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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Native_Data_Set_Environment: Mac OSX 11.6.1, Microsoft Excel 16.47.1 for Mac Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Thermogravimetric analyzer is calibrated to weight and temperature by instrument manufacturers. Logical_Consistency_Report: Each sample was run in triplicate to verify consistency across sample runs. Completeness_Report: 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. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: 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_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Vertical accuracy was determined with ROV Jason's altimeter, which is accurate to less than 1 m. No formal positional accuracy tests were conducted. Lineage: Process_Step: Process_Description: 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. Process_Date: 20220613 Process_Step: Process_Description: 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. Process_Date: 20230824 Process_Step: Process_Description: 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. Process_Date: 20250930 Source_Produced_Citation_Abbreviation: results Process_Step: Process_Description: Results from the Thermogravimetric analyses were combined into a comma-delimited text values document (TN403_TGA.csv). Source_Used_Citation_Abbreviation: results Process_Date: 20260317 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Point Point_and_Vector_Object_Count: 382070 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.001 Longitude_Resolution: 0.001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: TN403_TGA.csv Entity_Type_Definition: 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. Entity_Type_Definition_Source: Producer defined Attribute: Attribute_Label: Sample_name Attribute_Definition: The sample ID for each sample Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Unrepresentable_Domain: 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. Attribute: Attribute_Label: Sample_purge_gas Attribute_Definition: The gas that was in the chamber while the sample was run. Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: N2 Enumerated_Domain_Value_Definition: this sample was run in nitrogen gas Enumerated_Domain_Value_Definition_Source: producer defined Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: air Enumerated_Domain_Value_Definition: this sample was run in air. Enumerated_Domain_Value_Definition_Source: producer defined Attribute: Attribute_Label: Rate Attribute_Definition: This is the rate that the temperature increases by, in degrees Celsius per minute Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 5 Range_Domain_Maximum: 15 Attribute_Units_of_Measure: Degrees C per min Attribute_Measurement_Resolution: 5 Attribute: Attribute_Label: Time Attribute_Definition: This is the time of the run for each sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.00000 Range_Domain_Maximum: 56.98350 Attribute_Units_of_Measure: minutes Attribute_Measurement_Resolution: 0.00001 Attribute: Attribute_Label: Program_Temperature Attribute_Definition: This is the temperature of the chamber. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 30.009 Range_Domain_Maximum: 599.992 Attribute_Units_of_Measure: degrees Celsius Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: Sample_Temperature Attribute_Definition: This is the internal temperature of the sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 29.232 Range_Domain_Maximum: 595.372 Attribute_Units_of_Measure: degrees Celsius Attribute_Measurement_Resolution: 0.001 Attribute: Attribute_Label: Sample_Purge_Flow Attribute_Definition: This is the pressure at which the sample gas entered the chamber. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 16.45 Range_Domain_Maximum: 20.03 Attribute_Units_of_Measure: pounds per square inch (PSI) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: System_Purge_Flow Attribute_Definition: 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. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.00 Range_Domain_Maximum: 40.06 Attribute_Units_of_Measure: pounds per square inch (PSI) Attribute_Measurement_Resolution: 0.01 Attribute: Attribute_Label: Unsubtracted_Weight Attribute_Definition: This is the weight of the sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.9234 Range_Domain_Maximum: 12.4293 Attribute_Units_of_Measure: mg Attribute_Measurement_Resolution: 0.0001 Detailed_Description: Entity_Type: Entity_Type_Label: TN403_Location.csv Entity_Type_Definition: Comma-delimited file containing longitude, latitude, and depth information for the samples in the associated data file TN403_TGA.csv. Entity_Type_Definition_Source: Producer defined Attribute: Attribute_Label: Sample_name Attribute_Definition: The sample ID for each sample Attribute_Definition_Source: Producer defined Attribute_Domain_Values: Unrepresentable_Domain: 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. Attribute: Attribute_Label: Latitude Attribute_Definition: This is the latitude of the sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 40.6957 Range_Domain_Maximum: 41.0820 Attribute_Units_of_Measure: Decimal degrees Attribute_Measurement_Resolution: 0.0001 Attribute: Attribute_Label: Longitude Attribute_Definition: This is the longitude of the sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -127.5358 Range_Domain_Maximum: -127.4463 Attribute_Units_of_Measure: Decimal degrees Attribute_Measurement_Resolution: 0.0001 Attribute: Attribute_Label: Depth_meters Attribute_Definition: This is the depth of the sample. Attribute_Definition_Source: producer defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 3198 Range_Domain_Maximum: 3284 Attribute_Units_of_Measure: meters Attribute_Measurement_Resolution: 1 Overview_Description: Entity_and_Attribute_Overview: 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. Entity_and_Attribute_Detail_Citation: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: These data are available in .csv format contained in a single file accompanied by CSDGM FGDC-compliant metadata. Distribution_Liability: 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: comma-delimited text Format_Version_Number: Microsoft Excel 16.16.17 for Mac Format_Information_Content: File contains table in .csv format File_Decompression_Technique: No compression applied Transfer_Size: 1.77 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5066/P13WN2F7 Access_Instructions: Data can be downloaded using the Network_Resource_Name link and scrolling down to the TGA section. Fees: None. Technical_Prerequisites: These data can be viewed with Microsoft Excel or any text reader. Metadata_Reference_Information: Metadata_Date: 20260520 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center Contact_Person: PCMSC Science Data Coordinator Contact_Address: Address_Type: mailing and physical Address: 2885 Mission Street City: Santa Cruz State_or_Province: CA Postal_Code: 95060 Contact_Voice_Telephone: 831-427-4747 Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998