Mineralogy, rare earth elements, and strontium isotopic composition of phosphorites and phosphatized rocks from the Rio Grande Rise, south Atlantic Ocean

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Frequently anticipated questions:

What does this data set describe?

Title:
Mineralogy, rare earth elements, and strontium isotopic composition of phosphorites and phosphatized rocks from the Rio Grande Rise, south Atlantic Ocean
Abstract:
Phosphorites and phosphatized rocks from the summit of the Rio Grande Rise (RGR) in the south Atlantic Ocean were collected via dredge during the oceanographic research cruise RGR1 to the western RGR. The location (latitude, longitude, depth), mineralogy, concentrations of phosphorus and rare earth elements, and 87Sr/86Sr ratios of phosphorites and phosphatized FeMn crusts, ironstones, and carbonates from 10 dredge sites are presented here. These data were used to determine the presence of carbonate fluorapatite in different rock types, the age of carbonate fluorapatite and the characteristics of the phosphatizing fluid.
Supplemental_Information:
Samples analyzed for this data release were collected on a cruise funded by Funda‡?o de Amparo a Pesquisa do Estado de S?o Paulo (FAPESP) grant number 14/50820-7 for the project titled ?Marine ferromanganese deposits: a major resource of E-tech elements,? which is an international collaboration between Natural Environment Research Council (UK) and FAPESP (Brazil). The Rio Grande Rise is in international waters; therefore, no permission is required to distribute data for these samples. A data report about the cruise can be found at: https://doi.org/10.3389/fmars.2019.00252. Additional information on the USGS field activity from which these data are derived can is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-602-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. How might this data set be cited?
    Benites, Mariana, and Mizell, Kira, 2021, Mineralogy, rare earth elements, and strontium isotopic composition of phosphorites and phosphatized rocks from the Rio Grande Rise, south Atlantic Ocean: data release DOI: 10.5066/P9CFVCWN, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -39.3750000
    East_Bounding_Coordinate: -29.1015625
    North_Bounding_Coordinate: -29.4778612
    South_Bounding_Coordinate: -34.4778612
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 26-Jan-2018
    Ending_Date: 31-Mar-2021
    Currentness_Reference:
    ground condition at time data were collected
  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 (54)
    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 0.0001. Longitudes are given to the nearest 0.0001. 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?
    RGR1_P_mineral_chem_Sr_data.csv
    table containing results from analyses of phosphorites and phosphatized rocks at the latitude, longitude, and water depth of each sample location. (Source: Producer defined)
    Sample_Dredge_ID
    The sample and dredge ID for each sample (Source: Producer defined) The sample names include cruise ID (RGR1), the dredge number (D, denoting dredge, followed by a number), and a further underscored number to denote the sample number.
    Layer_Interval
    The depth interval, measured in millimeters from the top of the stratigraphic section, that encompasses each rock layer sample (Source: Producer defined) Layer intervals (starting with L) are listed as ranges of integer values that represent the depth in millimeters below the surface of the crust. Samples with ?CFA lens? listed for the layer interval represent results for a lens of phosphorite discretely contained in that layer interval. Samples with ?Substrate? listed represents the substrate rock of ferromanganese crusts. Samples with ?Bulk? represent whole-rock analysis.
    Type
    The rock type for each sample or sample layer (Source: Producer defined)
    ValueDefinition
    Phosphatized Fe-Mn crustthe sample or subsample is a phosphatized ferromangense (Fe-Mn) crust
    Carbonatethe sample or subsample is a carbonate
    Ironstonethe sample or subsample is an ironstone
    Phosphoritethe sample or subsample is a phosphorite
    Phosphorite lensthe sample or subsample is a phosphorite lens within ferromanganese (Fe-Mn) crust layers
    Latitude
    Latitude at which sample was collected (Source: producer defined)
    Range of values
    Minimum:-31.1558
    Maximum:-30.6253
    Units:decimal degrees
    Resolution:0.0001
    Longitude
    Longitude at which sample was collected (Source: producer defined)
    Range of values
    Minimum:-36.2082
    Maximum:-34.8301
    Units:decimal degrees
    Resolution:0.0001
    Water_Depth
    Water depth in meters at which the sample was collected (Source: producer defined)
    Range of values
    Minimum:633.5
    Maximum:825.5
    Units:meters (m)
    Resolution:0.5
    Major_minerals
    Minerals that constitute more than 25% of the total mineralogy based on semi-quantitative estimation calculated using the intensities of the peaks and weighting factors relative to quartz (Cook and others, 1975; Hein and others, 1988). (Source: producer defined) List of minerals. None means that no minerals occurred within this percentage range.
    Moderate_minerals
    Minerals that constitute 5-25% of the total mineralogy based on semi-quantitative estimation calculated using the intensities of the peaks and weighting factors relative to quartz (Cook and others, 1975; Hein and others, 1988). (Source: producer defined) List of minerals. None means that no minerals occurred within this percentage range.
    Minor_minerals
    Minerals that constitute less than 5% of the total mineralogy based on semi-quantitative estimation calculated using the intensities of the peaks and weighting factors relative to quartz (Cook and others, 1975; Hein and others, 1988). (Source: producer defined) List of minerals. None means that no minerals occurred within this percentage range.
    P
    Phosphorus concentration in each sample (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.05
    Maximum:13.7
    Units:weight percent
    Resolution:0.01
    La
    Lanthanum concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:2.00
    Maximum:167
    Units:parts per million
    Resolution:0.01
    Ce
    Cerium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:1.68
    Maximum:141
    Units:parts per million
    Resolution:0.01
    Pr
    Praseodymium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.49
    Maximum:28.3
    Units:parts per million
    Resolution:0.01
    Nd
    Neodyium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:1.80
    Maximum:126
    Units:parts per million
    Resolution:0.01
    Sm
    Samarium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.40
    Maximum:24.5
    Units:parts per million
    Resolution:0.01
    Eu
    Europium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.08
    Maximum:5.52
    Units:parts per million
    Resolution:0.01
    Gd
    Gadolinium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.39
    Maximum:28.6
    Units:parts per million
    Resolution:0.01
    Tb
    Terbium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.06
    Maximum:4.19
    Units:parts per million
    Resolution:0.01
    Dy
    Dysprosium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.40
    Maximum:26.4
    Units:parts per million
    Resolution:0.01
    Y
    Yttrium content in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:4.50
    Maximum:295
    Units:parts per million
    Resolution:0.01
    Ho
    Holmium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.08
    Maximum:5.99
    Units:parts per million
    Resolution:0.01
    Er
    Erbium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.24
    Maximum:18.0
    Units:parts per million
    Resolution:0.01
    Tm
    Thulium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.05
    Maximum:2.27
    Units:parts per million
    Resolution:0.01
    Yb
    Ytterbium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.20
    Maximum:13.6
    Units:parts per million
    Resolution:0.01
    Lu
    Lutetium concentration in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.03
    Maximum:2.02
    Units:parts per million
    Resolution:0.01
    Total_REY
    Summation of the concentration of rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) plus Y in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:10.0
    Maximum:686
    Units:parts per million
    Resolution:0.1
    HREY
    Percentage of the heavy rare earth elements calculated by taking the sum of heavy rare earth elements (Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and Y and dividing by the total_REY for each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:53.7
    Maximum:63.2
    Units:percent
    Resolution:0.1
    87Sr86Sr
    Isotopic ratio between 87Sr and 86Sr in each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.708296
    Maximum:0.709115
    Units:ratio (no units)
    Resolution:0.000001
    StdErr
    Percentage standard error of the 87Sr/86Sr isotopic ratio for each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.000199
    Maximum:0.000857
    Units:percent
    Resolution:0.000001
    2StdErr
    Two times the standard error of the 87Sr/86Sr isotopic ratio for each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.0000039
    Maximum:0.0000171
    Units:percent
    Resolution:0.0000001
    2SD
    Two times the standard deviation for the 87Sr/86Sr isotopic ratio for each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.0000503
    Maximum:0.0002168
    Units:ratio (no unit)
    Resolution:0.0000001
    Sr_age
    CFA and calcite ages based on comparison of 87Sr/86Sr values for each sample to the Cenozoic seawater curve of calibrated ages by McArthur and others (2012). Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:1.375
    Maximum:22.250
    Units:million years
    Resolution:0.005
    Age_error
    Age error for each sample. Values of -9999 indicate the parameter was not measured. (Source: standard reporting value in geochemistry)
    Range of values
    Minimum:0.050
    Maximum:0.675
    Units:million years
    Resolution:0.001
    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)
    • Mariana Benites
    • 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?

These samples were collected to help determine the history of phosphatization of the summit of the Rio Grande Rise, as recorded by the carbonate fluorapatite in different rock types.

How was the data set created?

  1. From what previous works were the data drawn?
    XRD (source 1 of 3)
    USGS Pacific Coastal and Marine Science Center Marine Minerals Laboratory, 2018, X-ray diffraction Mineralogy.

    Online Links:

    • None

    Type_of_Source_Media: rock powders
    Source_Contribution:
    X-ray powder diffraction analysis to determine the mineralogy. Rock powder was wet mounted on zero-diffraction sample holders using alcohol and measured using a Cu-kà radiation source and graphite monochromator. Each sample was scanned from 4 degrees to 70 degrees 2-theta at 40 kilovolts and 45 milliamperes The diffractograms were interpreted using the Philips High Score Plus software and the International Centre for Diffraction Database. Semi-quantitative percentages of mineral phases were calculated based on the intensities of the peaks and weighting factors relative to quartz (Cook and others, 1975; Hein and others, 1988).
    geochemistry (source 2 of 3)
    Laboratory, SGS Minerals, 2018, Geochemical Element Analysis.

    Online Links:

    Type_of_Source_Media: rock powders
    Source_Contribution:
    Geochemical analysis to determine element concentrations. Phosphorus (P) was determined by X-Ray Fluorescence. Lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), yttrium (Y), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu) were all determined by performing lithium metaborate fusion of rock powders followed by inductively coupled mass spectrometry analysis.
    87Sr86Sr (source 3 of 3)
    University of California at Santa Cruz V.M. Keck Isotope Laboratory, 2018, Strontium Isotope Analysis.

    Online Links:

    Type_of_Source_Media: rock powders
    Source_Contribution:
    Concentrated nitric acid digestion of samples at 90 degrees Celsius, column chemistry using Sr-SPEC resin, and analysis by a Isotopx Phoenix x62 Thermal Ionization Mass Spectrometer (TIMS). Isotope values are presented as a ratio of 87Sr to 86Sr, and analytical precision is expressed by the standard error.
  2. How were the data generated, processed, and modified?
    Date: 01-Jun-2018 (process 1 of 5)
    Powder aliquots were drilled from the different rock samples using a diamond-coated drill bit and then ground using an agate mortar and pestle to approximately 75 micrometers.
    Date: 01-Nov-2018 (process 2 of 5)
    Total rare earth elements plus yttrium (Total_REY) were calculated by summing the concentration of rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) plus Y in each sample. Percentage of the heavy rare earth elements was calculated by taking the sum of heavy rare earth elements (Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and Y and dividing the sum by the total_REY value for each sample. Data sources used in this process:
    • geochemistry
    Date: 13-Jul-2018 (process 3 of 5)
    A sequence of chemical leaches was applied to the powder aliquots to isolate the carbonate fluorapatite from the different rock types for chemical and Sr isotopic analyses using the procedure of Ruttenberg (1992). First, Fe and Mn oxyhydroxides were removed by leaching 3 g of powdered (<75 micrometers) samples in 1 L of a leaching solution of Na-citrate, Na-bicarbonate, and Na-dithionite (pH 8) for 24 hours. The solution was then filtered (2.7 micrometer paper filter), the residue washed in a 1 M MgCl2 solution (pH 8) and filtered again. For calcite removal, the residue from the previous step was stirred in a 0.5 M triammonium citrate solution (pH 8.1) for 10 hours, after the procedure of Silverman and others (1952). After calcite leaching, the solution was filtered (2.7 micrometer paper filter), and the residues were washed in Milli-Q water, centrifuged, and placed in a sonic bath (repeated five times). Finally, the organic matter was removed by stirring the residues with a 30 percent H2O2 solution. Ironstones and phosphorite samples were treated only for calcite and organic matter removal, and carbonate samples were treated only for the removal of organic matter. The removal of each phase was confirmed by XRD at the end of each step.
    Date: 10-Nov-2019 (process 4 of 5)
    The age (Sr_age) of the carbonate fluorapatite (CFA) in select samples was determined by comparing the 87Sr/86Sr ratio of the samples to the Cenozoic seawater curve of 87Sr/86Sr values compiled by McArthur and others (2012). Data sources used in this process:
    • 87Sr86Sr
    Date: 01-May-2021 (process 5 of 5)
    Results from the lab analyses, the isotope age data, location data, and sample information were combined into a comma-delimited text values document (RGR1_P_mineral_chem_Sr_data.csv). Cells designated by -9999 indicate that no analysis was performed. Data sources used in this process:
    • XRD
    • geochemistry
    • 87Sr86Sr
  3. What similar or related data should the user be aware of?
    Benites, Mariana, Hein, James R., Mizell, Kira, and Jovane, Luigi, 2021, Miocene phosphatization of rocks from the summit of Rio Grande Rise, southwest Atlantic Ocean.

    Online Links:

    Other_Citation_Details:
    Benites, M., Hein, J.R., Mizell, K., and Jovane, L., XXXX, Miocene phosphatization of rocks from the summit of Rio Grande Rise, southwest Atlantic Ocean: Paleoceanography and Paleoclimatology, (in press).
    McArthur, J., Howart, R.J., and Shields, G.A., 2012, Strontium isotope stratigraphy.

    Online Links:

    Other_Citation_Details:
    McArthur, J., Howarth, R.J., and Shields, G.A., 2012, Strontium isotope stratigraphy, in Gradstein, F., Ogg, J.G., Schmitz, M.D., and Ogg, G.M., eds., The Geologic Time Scale: Oxford, Elsevier, p 127?144).
    Cook, H.E., Johnson, P.D., Matti, J.C., and Zemmels, I., 1975, Methods of sample preparation and x-ray diffraction data analysis, X-Ray Mineralogy Laboratory, Deep Sea Drilling Project, University of California, Riverside.

    Online Links:

    Other_Citation_Details:
    Cook, H.E., Johnson, P.D., Matti, J.C., Zemmels, I, 1975, Methods of sample preparation and x-ray diffraction data analysis, X-Ray Mineralogy Laboratory, Deep Sea Drilling Project, University of California, Riverside: Chapter IV, Deep Sea Drilling Project Initial Reports, v. 28, p. 999?1007.
    Hein, J.R., Schwab, W.C., and Davis, A.S., 1988, Cobalt- and platinum-rich ferromanganese crusts and associated substrate rocks from the Marshall Islands.

    Online Links:

    Other_Citation_Details:
    Hein, J.R., Schwab, W.C., and Davis, A.S., 1988, Cobalt- and platinum-rich ferromanganese crusts and associated substrate rocks from the Marshall Islands: Marine Geology, v. 78, p. 255?283.
    Silverman, S., Fuyat, R., and Weiser, J., 1952, Quantitative determination of calcite associated with carbonate-bearing apatites.

    Online Links:

    Other_Citation_Details:
    Silverman, S., Fuyat, R., and Weiser, J., 1952, Quantitative determination of calcite associated with carbonate-bearing apatites: American Mineralogist, v. 37, p. 211?222
    Ruttenberg, K.C., 1992, Development of a sequential extraction method for different forms of phosphorus in marine sediments..

    Online Links:

    Other_Citation_Details:
    Ruttenberg, K.C., 1992, Development of a sequential extraction method for different forms of phosphorus in marine sediments: Limnology and Oceanography, v. 37, p. 1460?1482.

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

  1. How well have the observations been checked?
    All geochemistry and strontium age data were calibrated against certified reference materials.
  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 ships? GPS navigation, which is accurate to less than 5 m.
  3. How accurate are the heights or depths?
    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. Many samples do not have chemistry data because it was done on representative samples only. 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?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
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. Please recognize and acknowledge the U.S. Geological Survey and the University of Sao Paulo as the originators of the dataset and in products derived from these data.
  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: 0.011
      Network links: https://doi.org/10.5066/P9CFVCWN
    • 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: 03-Jun-2021
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)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/CMGDS_DR_tool/DR_P9CFVCWN/RGR1_P_mineral_chem_Sr_metadata.faq.html>
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