X-ray diffraction data for heat treated samples of hydrothermal minerals from seamounts within the Tuvalu Exclusive Economic Zone

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?
   Mizell, Kira, 20230125, X-ray diffraction data for heat treated samples of hydrothermal minerals from seamounts within the Tuvalu Exclusive Economic Zone: data release DOI: 10.5066/P95CIHSU, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P95CIHSU

   This is part of the following larger work.
   Mizell, Kira, 2023, Major and trace element geochemistry and mineralogy of ferromanganese crusts from seamounts within the Tuvalu Exclusive Economic Zone: data release DOI:10.5066/P95CIHSU, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P95CIHSU

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: 179.869
   East_Bounding_Coordinate: 179.871
   North_Bounding_Coordinate: -11.331
   South_Bounding_Coordinate: -11.329
   

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

   Beginning_Date: 22-Jul-2013

   Ending_Date: 06-Sep-2022

   Currentness_Reference:

   Date that the last process step was completed

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

   Geospatial_Data_Presentation_Form: comma-delimited text
   

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 (3823)
   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 0.001. Longitudes are given to the nearest 0.001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      
7. How does the data set describe geographic features?

   Tuvalu_RR1310_FeMn_115C XRD_RawData.csv

   Comma-delimited file containing results from x-ray diffraction analyses of ferromanganese crusts. Location information for the samples are included in each Attribute Definition of this metadata file and not the data table. The header for each column of diffraction data is a sample name, which follows the scheme of dredge number followed by a hyphenated sample number, then an L followed by a number and a stratigraphic location (lower, middle, upper) to explain specific layers that were analyzed. (Source: Producer defined)

   Position

   The two-theta angle at which the x-ray diffractometer measured the X-ray diffraction of the powdered sample (Source: instrument defined)

   Range of values
   Minimum:	5.0084
   Maximum:	69.9824
   Units:	degrees
   Resolution:	0.0001

   D28A-01_L1_LOWER

   X-ray diffraction intensity value at the two-theta angle listed in the corresponding row in the Position attribute. The location for sample D28A-01_L1_LOWER is -11.330 N, 179.870 E, and 2842 m water depth (Source: producer defined)

   Range of values
   Minimum:	13.0000
   Maximum:	682.9668
   Units:	counts
   Resolution:	0.0001

   D28A-01_L2_MIDDLE

   X-ray diffraction intensity value at the two-theta angle listed in the corresponding row in the Position attribute. The location for sample D28A-01_L2_MIDDLE is -11.330 N, 179.870 E, and 2842 m water depth (Source: producer defined)

   Range of values
   Minimum:	9.1451
   Maximum:	1268.3867
   Units:	counts
   Resolution:	0.0001

   D28A-01_L3_UPPER

   X-ray diffraction intensity value at the two-theta angle listed in the corresponding row in the Position attribute. The location for sample D28A-01_L3_UPPER is -11.330 N, 179.870 E, and 2842 m water depth (Source: producer defined)

   Range of values
   Minimum:	13.8953
   Maximum:	364.3586
   Units:	counts
   Resolution:	0.0001

   Entity_and_Attribute_Overview: The first line of the csv file is a header line.
   Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Kira Mizell
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@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: 26-Sep-2016 (process 1 of 4)

   USGS scientists requested these ferromanganese crust samples from the Oregon State University Marine and Geology Repository where they had been archived. Ferromanganese crust samples were sent to USGS for subsampling and mineralogical analyses.

   Date: 01-May-2017 (process 2 of 4)

   At USGS, individual layers were sampled from the hydrothermal sample using a ceramic knife and then ground using an agate mortar and pestle to approximately 75 micrometers. Samples were then placed in crucibles and heated in an oven to 115 C for 48 hours.

   Date: 01-Nov-2018 (process 3 of 4)

   After cooling from the previous heat step, powdered samples were backloaded and tamped into sample holders and run in a Panalytical XÕPert3 x-ray diffractometer (XRD; https://www.malvernpanalytical.com/) with CuK-alpha radiation and graphite monochromator. Measurements were taken with the following scan parameters: step size of 0.017 degrees two-theta between 5 degrees and 70 degrees two-theta, power of 40 kilovolts and 45 milliamps, scan rate of 60 seconds per step, a sample holder rotational speed of 0.03 degrees per second, and averaged triplicate scans at three different stage wobble angles (-1, 0, and 1 degree). Data sources used in this process:

   • samples

   Date: 05-Sep-2022 (process 4 of 4)

   Results from the diffraction analyses were combined into a comma-delimited text values document (Tuvalu_RR1310_FeMn_115C XRD_RawData.csv). Data sources used in this process:

   • results

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?
   X-ray diffraction data were tested for accuracy by intermittently analyzing a powdered quartz reference sample to verify the one hundred intensity peak at 26.6 degree two-theta. When the quartz peak was in the proper position, we infer that other measured peak positions in the sample are accurate. Peak intensities are considered semiquantitative since no quantitative standards were analyzed for this dataset.
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted. The horizontal accuracy was determined with the ship's GPS navigation, which is accurate to less than 5 m.
3. How accurate are the heights or depths?
   The singular value for water depth for each sample was calculated from shipboard dredge log records to account for ship-based depth soundings, the length of dredge wire out, movement by the ship, approximate seamount slope, and multiple bites of the dredge along each dredge track in order to maximize location accuracy. A formal accuracy assessment of the vertical positional information in the dataset has not been conducted.
4. Where are the gaps in the data? What is missing?
   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.
5. How consistent are the relationships among the observations, including topology?
   No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in .csv format contained in a single file.
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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	File contains table in .csv format in format comma-delimited text (version Microsoft Excel 16.16.17 for Mac) Size: 0.12485
     Network links:	https://www.sciencebase.gov/catalog/file/get/63b65086d34e92aad3cacaf0 https://www.sciencebase.gov/catalog/item/63b65086d34e92aad3cacaf0 https://doi.org/10.5066/P95CIHSU

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   These data can be viewed with Microsoft Excel or any text reader.

Who wrote the metadata?

Dates:

Last modified: 25-Jan-2023

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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