Rock magnetic measurements of sediments from the Terrebonne Basin, Gulf of America (Gulf of Mexico), Walker Ridge 313 Site H

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Phillips, Stephen 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 DOI:10.5281/zenodo.14775361, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts, USA.

   Online Links:

   • http://doi.org/10.5281/zenodo.14775361

   Other_Citation_Details:

   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

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -91.67608
   East_Bounding_Coordinate: -91.67599
   North_Bounding_Coordinate: 26.66260
   South_Bounding_Coordinate: 26.66228
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 04-Aug-2023

   Ending_Date: 27-Aug-2023

   Currentness_Reference:

   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.

5. What is the general form of this data set?

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (438)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is NAD 27.
      The ellipsoid used is Clark ellipsoid of 1866.
      The semi-major axis of the ellipsoid used is 6378206.400000.
      The flattening of the ellipsoid used is 1/294.9786982.
      

      Vertical_Coordinate_System_Definition:

      Depth_System_Definition:

      Depth_Datum_Name: local surface - depth below sea floor
      Depth_Resolution: 0.005
      Depth_Distance_Units: meters
      Depth_Encoding_Method: attribute values
      

7. How does the data set describe geographic features?

   "UT-GOM2-2_MS3-MS2B-mag-summary"

   Microsoft Excel workbook that contains tabulated magnetic susceptibility data by depth for UT-GOM2-2 cores. (Source: producer defined)

   Expedition

   Expedition name UT-GOM2-2 for all entries (Source: U.S. Geological Survey) user defined text field

   Area

   Lease block area within the Gulf of America. All values are Walker Ridge 313 (WR313). (Source: U.S. Geological Survey) user defined text field

   Site

   Site within the WR313 area. In this case all from the H site. (Source: U.S. Geological Survey) user defined text field

   Hole

   Two holes were drilled at the WR313 H site: 002 and 003. (Source: U.S. Geological Survey) user defined text field

   Core

   Core number, increasing with depth in each hole. (Source: 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. (Source: U.S. Geological Survey) user defined

   Section

   Section cut within the core. (Source: U.S. Geological Survey) user defined

   Piece

   Peice cut within each core section. Some sections were not cut into pieces. NaN = no data. (Source: 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). (Source: U.S. Geological Survey) user defined

   Sample top (depth in section, cm)

   Depth in section of the top of the sample. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	0
   Maximum:	186
   Units:	centimeters

   Sample bottom (depth in section, cm)

   Depth in section of the bottom of the sample. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	3
   Maximum:	200
   Units:	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. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.30
   Maximum:	859.22
   Units:	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. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.40
   Maximum:	859.24
   Units:	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. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.30
   Maximum:	859.22
   Units:	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. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.4
   Maximum:	859.24
   Units:	meters below seafloor (mbsf)

   Sample weight (g)

   Weight of the sediment in the plastic paleomagnetic cube. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	6.97
   Maximum:	16.50
   Units:	grams (g)

   LF mag susc (m3/kg)

   Low-frequency (LF) magnetic susceptibility. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.96E-08
   Maximum:	2.08E-06
   Units:	meters cubed per kilogram (m3/kg)

   HF mag susc (m3/kg)

   High-frequency (LF) magnetic susceptibility. (Source: U.S. Geological Survey)

   Range of values
   Minimum:	1.60E-08
   Maximum:	2.07E-06
   Units:	meters cubed per kilogram (m3/kg)

   Entity_and_Attribute_Overview:

   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.

   Entity_and_Attribute_Detail_Citation:

   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 .

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Phillips, Stephen C.
   • Widlansky, S.J.
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   Stephen Phillips

   U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center

   Research Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   508-548-8700 x2240 (voice)

   scphillips@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 2024 (process 1 of 1)

   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 Person who carried out this activity:
   

   Stephen Phillips

   U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center

   Research Geologist

   384 Woods Hole Rd.

   Woods Hole, MA
   

   508-4548-8700 x2240 (voice)

   scphillips@usgs.gov

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   
2. How accurate are the geographic locations?
   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.
3. How accurate are the heights or depths?
   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.
4. Where are the gaps in the data? What is missing?
   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.
5. How consistent are the relationships among the observations, including topology?
   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.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   Zenodo

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

   Meyrin, Geneva
   

   Switzerland

   +41 22 76 77777 (voice)

   info@zenodo.org
2. What's the catalog number I need to order this data set? 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.
3. What legal disclaimers am I supposed to read?
   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.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	XLSX (version Created in Excel Office 365 version 2408) Size: 1
     Network links:	http://doi.org/10.5281/zenodo.14775361

   • Cost to order the data: None.

Who wrote the metadata?

Dates:

Last modified: 08-Dec-2025

Metadata author:

Stephen C. Phillips

U.S. Geological Survey, Northeast Region, Woods Hole Coastal and Marine Science Center

Research Geologist

U.S. Geological Survey

Woods Hole, MA

508-548-8700 x2240 (voice)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the person is no longer with USGS.

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)