Phillips, Stephen C. Widlansky, S.J. 2025 1 dataset DOI:10.5281/zenodo.14775361 Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts, USA U.S. Geological Survey, Coastal and Marine Hazards and Resources Program Suggested citation: Phillips, S.C., and Widlansky, S.J., 2025, Rock magnetic measurements of sediments from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site H [Dataset]: Zenodo dataset, http://doi.org/10.5281/zenodo.14775361 http://doi.org/10.5281/zenodo.14775361 These data include magnetic susceptibility measured at high and low frequency on discrete sediment samples collected from the Terrebonne Basin, Gulf of America, drilled as part of the Deepwater Hydrate Coring Expedition (UT-GOM2-2) at Walker Ridge 313 Site H Holes H003 and H002.This 2023 Department of Energy funded project was focused on better understanding microbial methane generation in marine sediments and characterizing coarse-grained gas hydrate reservoirs. Sediments were recovered continuously down to 155 meters below the seafloor and as spot cored intervals down to 861 meters below the seafloor. Cores were recovered using both conventional and pressure cores. Mass-normalized and frequency-dependent magnetic susceptibility was measured to support interpretations of depositional and diagenetic processes. Magnetic susceptibility values can be a first order indicator of ferrimagnetic iron oxides and/or sulfides that can be used for interpreting the paleoenvironmental and diagenetic history of the sediments in sedimentary basins This Microsoft Excel workbook contains data in a single tab. The samples were collected from cores recovered during the UT-GOM2-2 expedition in 2023. Additional information with regards to this field activity can be found at https://cmgds.marine.usgs.gov/services/activity.php?fan=2023-021-FA . All samples were collected from split cores and whole round porewater squeeze cakes during a post-expedition sampling party in September 2023. 20230804 20230827 Ground condition. Cores were collected in August 2023 on the D/V Q4000 using conventional (advanced piston coring and extended core barrel coring) and pressure coring (Pressure Coring Tool with Ball Valve). Conventional and depressurized pressure cores were stored refrigerated until split in September 2023. All samples were collected in 8 cm3 plastic paleomagnetic boxes within hours of splitting. Samples were measured for magnetic susceptibility the same day. Complete Future version expected with additional rock magnetic data. -91.67608 -91.67599 26.66260 26.66228 None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Woods Hole Coastal and Marine Science Center WHCMSC U.S. Department of Energy DOE National Energy Technology Laboratory NETL University of Texas at Austin UT-Austin methane hydrates carbon cycle magnetic susceptibility USGS Thesaurus drilling and coring piston coring rotary drilling core analysis magnetic susceptibility analysis sedimentation diagenesis interagency programs magnetic susceptibility ISO 19115 Topic Category geoscientificInformation USGS Metadata Identifier USGS:cd721a9d-bd5e-48b5-af8b-75c1f36c263a Geographic Names Information System (GNIS) Gulf of America None Gulf of Mexico Terrebonne Basin Walker Ridge No access constraints. Please see 'Distribution Information' for details. Public domain (CC0-1.0) data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. All data collection was funded by the U.S. Department of Energy National Energy Technology Laboratory. Stephen Phillips U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Research Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2240 scphillips@usgs.gov For each of the rock magnetic property measurements described in the Process Steps below, standards relevant to the particular property were entrained in the measurement sequence to ensure fidelity within each Process Step. The standards are noted in the Process Steps as well as the citations for those references. This Microsoft Excel workbook represents the complete collected and calculated data in support of dual-frequency magnetic susceptibility measurements for the UT-GOM2-2 project. Horizontal position was determined by GPS satellite data, which provided guidance information for the dynamic positioning system (DPS) utilized by the D/V Q4000. The DPS also utilizes inputs from current, wind, tide, and wave data to control eight azimuthal thrusters beneath the ship’s hull. The thrusters are capable of 360-degree adjustment. Given the DPS capabilities, borehole locations for the D/V Q4000 are considered to be accurate to a radius of 15 meters. Details for a very similar DPS system us provided in: Chikyu Hakken – Earth Discovery, Volume 1, Spring 2005, published by JAMSTEC’s Center for Deep Earth Exploration: https://www.jamstec.go.jp/chikyu/e/magazine/backnum/pdf/hk_01_e.pdf. North American Datum 27 (NAD27) is the horizontal datum used by the DPS on the D/V Q4000. Coring depth measurements used on the D/V Q4000 during the UT-GOM2-2 expedition followed standard International Ocean Discovery Program (IODP) protocols using analogous coring tools. Assessment of these protocols by IODP had determined the vertical position accuracy is on the order of centimeters to meters relative to each coring point, depending on core recovery. Additional information about the depth conventions and accuracy are on pages 8 and 9 of the IODP report “IODP Depth Scales Terminology”: http://www.iodp.org/policies-and-guidelines/142-iodp-depth-scales-terminology-april-2011/file. Depth resolution ranges from 0.01 to 1 meter. Sediment cores were collected via wireline coring tools (advance piston coring, extended core barrel coring, and pressure coring) and cut into sections at sea. Hole H002 is located at 26.66228° latitude and -91.67601° longitude at the seafloor. Hole H003 is located at 26.66263° latitude and -91.67599° latitude at the seafloor. Whole round sections were capped, taped, and stored refrigerated at 4°C. Once transported to shore-based science operations in Salt Lake City, the core sections were split lengthwise, and samples were collected from the working half of the core sections at room temperature conditions within hours of splitting. Samples for dual-frequency magnetic susceptibility measurements were collected in 8cm3 (2 x 2 x 2 cm) plastic paleomagnetic cubes following IODP procedures (Richter et al., 2007). Samples were sampled immediately after core splitting, then weighed in tared plastic paleomagnetic cubes. Each sample was measured that same day at room temperature using a Bartington MS3 Magnetic Susceptibility Meter with a Bartington MS2B Dual-Frequency Magnetic Susceptibility Sensor following the steps set forth in the operating manual (Bartingon Instruments, 2022). Each sample was measured for low frequency (LF) magnetic susceptibility at 465 Hz with an air blank before and after the measurement. Each sample was measured for high frequency (HF) magnetic susceptibility at 4650 Hz with an air blank before and after the measurement. The LF and HF values were normalized on a mass-basis using the instrument software. Frequency dependence of magnetic susceptibility was calculated in the instrument software using the formula of Dearing et al. (1996). Reference: Bartington Instruments, 2022, MS3 Magnetic Susceptibility Meter, https://www.bartingtondownloads.com/wp-content/uploads/OM3227.pdf. Accessed June 5, 2025 Dearing, J.A., Dann, R.J.L., Hay, K., Lees, J.A., Loveland, P.J., Maher, B.A., and O’Grady, K., 1996, Frequency-dependent susceptibility measurements of environmental materials: Geophysical Journal International, v. 124, p. 228-240, https://doi.org/10.1111/j.1365-246X.1996.tb06366.x Richter, C., Acton, G., Endris, C., and Radsted, M., 2007, Handbook for shipboard paleomagnetists: ODP Technichal Note, 34, https://doi.org/10.2973/odp.tn.34.2007 2024 Stephen Phillips U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Research Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-4548-8700 x2240 scphillips@usgs.gov Point Point 438 0.00001 0.00001 decimal degrees NAD 27 Clark ellipsoid of 1866 6378206.400000 294.9786982 local surface - depth below sea floor 0.005 meters attribute values "UT-GOM2-2_MS3-MS2B-mag-summary" Microsoft Excel workbook that contains tabulated magnetic susceptibility data by depth for UT-GOM2-2 cores. producer defined Expedition Expedition name UT-GOM2-2 for all entries U.S. Geological Survey user defined text field Area Lease block area within the Gulf of America. All values are Walker Ridge 313 (WR313). U.S. Geological Survey user defined text field Site Site within the WR313 area. In this case all from the H site. U.S. Geological Survey user defined text field Hole Two holes were drilled at the WR313 H site: 002 and 003. U.S. Geological Survey user defined text field Core Core number, increasing with depth in each hole. U.S. Geological Survey user defined Core type Core type used to recover core. H is advanced piston core, X is extended core barrel, CS is pressure coring tool with ball valve in the cutting shoe configuration, and FB is the pressure coring tool with ball valve in the face bit configuration. U.S. Geological Survey user defined Section Section cut within the core. U.S. Geological Survey user defined Piece Peice cut within each core section. Some sections were not cut into pieces. NaN = no data. U.S. Geological Survey user defined Sample code Sample code used within the expedition to track sample types. Samples in this data set were collected as "rock magnetic" samples (RMG), "rock magnetic anomaly" samples (ARM), "interstitial water regular" whole rounds (IWR), and "Interstitial water organic whole rounds (IWO). U.S. Geological Survey user defined Sample top (depth in section, cm) Depth in section of the top of the sample. U.S. Geological Survey 0 186 centimeters Sample bottom (depth in section, cm) Depth in section of the bottom of the sample. U.S. Geological Survey 3 200 centimeters Archived sample top depth (mbsf) Sample top depth in meters below seafloor (mbsf) based on archived core lengths, that does not account for expansion of the core. This may allow for overlap between cores. Equivalent to IODP CSF-A terminology. U.S. Geological Survey 1.30 859.22 meters below seafloor (mbsf) Archived sample bottom depth (mbsf) Sample bottom depth in meters below seafloor (mbsf) based on archived core lengths, that does not account for expansion of the core. This may allow for overlap between cores. Equivalent to IODP CSF-A terminology. U.S. Geological Survey 1.40 859.24 meters below seafloor (mbsf) Compressed sample top depth (mbsf) Sample top depth in meters below seafloor (mbsf) based on linearly-compressed core depths, accounting for expansion of the core (total length of core = length of drilling advance). Equivalent to IODP CSF-B terminology. U.S. Geological Survey 1.30 859.22 meters below seafloor (mbsf) Compressed sample bottom depth (mbsf) Sample bottom depth in meters below seafloor (mbsf) based on linearly-compressed core depths, accounting for expansion of the core (total length of core = length of drilling advance). Equivalent to IODP CSF-B terminology. U.S. Geological Survey 1.4 859.24 meters below seafloor (mbsf) Sample weight (g) Weight of the sediment in the plastic paleomagnetic cube. U.S. Geological Survey 6.97 16.50 grams (g) LF mag susc (m3/kg) Low-frequency (LF) magnetic susceptibility. U.S. Geological Survey 1.96E-08 2.08E-06 meters cubed per kilogram (m3/kg) HF mag susc (m3/kg) High-frequency (LF) magnetic susceptibility. U.S. Geological Survey 1.60E-08 2.07E-06 meters cubed per kilogram (m3/kg) The workbook UT-GOM2-2_MS3-MS2B-mag-summary.xlsx contains one tab. The first row in the XLSX file is a header row. The remaining rows contain all data included in this data release, with non-measurements given by “NaN" as indicated in the attribute definitions in this xml file. This file is part of a data release posted to the Zenodo UT-GOM2-2 community. hillips, S.C., and Widlansky, S.J., 2025, Rock magnetic measurements of sediments from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site H [Dataset]: Zenodo dataset, http://doi.org/10.5281/zenodo.14775361 . Zenodo mailing and physical address

European Organization for Nuclear Research: IT Department, Digital Repositories Section

Meyrin Geneva 1211 Switzerland +41 22 76 77777 info@zenodo.org Zenodo makes research results citable, and through OpenAIRE, integrates them into existing reporting lines to funding agencies. Citation information is also passed to DataCite and onto the scholarly aggregators. UT-GOM2-2_MS3-MS2B-mag-summary.xlsx (Excel spreadsheet of data). The Zenodo site does not have the complete XML 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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. XLSX Created in Excel Office 365 version 2408 1 http://doi.org/10.5281/zenodo.14775361 The link is the DOI link to the data release landing page where the data can be downloaded. None. 20251208 Stephen C. Phillips U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center Research Geologist mailing and physical

U.S. Geological Survey

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2240 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998