Sediment Grain size Data from sediment cores Collected from March 2012 to July 2013 along the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Numbers 12BIM01, 12BIM02, 12BIM05m and 13BIM06)

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Frequently anticipated questions:


What does this data set describe?

Title:
Sediment Grain size Data from sediment cores Collected from March 2012 to July 2013 along the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Numbers 12BIM01, 12BIM02, 12BIM05m and 13BIM06)
Abstract:
Scientists from the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted a time-series collection of shallow sediment cores from the back-barrier environments along the Chandeleur Islands, Louisiana from March 2012 through July 2013. The sampling efforts were part of a larger USGS study to evaluate the effects on the geomorphology of the Chandeleur Islands following the construction of an artificial sand berm in response to the Deep Water Horizon oil spill. The objective of this study was to evaluate the response of the back-barrier tidal and wetland environments to the berm. This report serves as an archive for sedimentological, radiochemical, and microbiological data derived from the sediment cores. Data is available for a time-series of four sampling periods: March 2012; July 2013; September 2012; and July 2013. Data is available in downloadable spreadsheet, Joint Photographic Experts Group and Portable Document File formats. Additional files included: ArcGIS shape files of the study sites, detailed results of sediment grain size analyses, and formal Federal Geographic Data Committee (FDGC) metadata.
Supplemental_Information:
Grain-size analyses were performed using a Coulter LS 200 (https://www.beckmancoulter.com/) particle-size analyzer, which uses laser diffraction to measure the size distribution of sediments ranging in size from 0.4 microns to 2 millimeters (mm) (clay to very coarse-grained sand). A total of 284 samples from 49 cores were analyzed. Prior to particle size analysis, organic material was chemically removed for the marsh core samples using 30% hydrogen peroxide (H2O2). The organic matter content in the back-barrier core samples were estimated from the LOI values to be ‹3% and therefore would not interfere with the LS200 measurements. Wet sediment from the marsh samples were dissolved in H2O2 overnight. The H2O2 was then evaporated and the sediment washed and centrifuged twice with deionized water. In order to prevent shell fragments from damaging the LS 200, particles greater than 1 mm in diameter were separated from all samples prior to analysis using a number 18 (1000 microns or 1 mm) U.S. standard sieve, which meets the American Society for Testing and Materials (ASTM) E11 standard specifications for determining particle size using woven-wire test sieves. Two subsamples from each sample were processed through the LS 200 a minimum of three runs each. The LS 200 measures the particle-size distribution of each sample by passing sediment suspended in solution between two narrow panes of glass in front of a laser. Light is scattered by the particles into characteristic refraction patterns measured by an array of photodetectors as intensity per unit area and recorded as relative volume for 92 size-related channels (bins). The size-classification boundaries for each bin were specified based on the ASTM E11 standard. The raw grain size data were then run through the free software program GRADISTAT (Blott and Pye, 2001; http://www.kpal.co.uk/gradistat), which calculates the mean, sorting, skewness, and kurtosis of each sample geometrically in metric units and logarithmically in phi units (Krumbein, 1934) using the Folk and Ward (1957) method. GRADISTAT also calculates the fraction of sediment from each sample by size category (for example, clay, coarse silt, fine sand) based on a modified Wentworth (1922) size scale. A macro function in Microsoft Excel, developed by the USGS SPCMSC, was applied to the data tocalculate average and standard deviation for each sample set (6 runs per sample), and highlight runs that varied from the set average by more than ±1.5 standard deviations. Excessive deviations from the mean are likely the result of equipment error or extraneous organic material in the sample and are not considered representative of the sample. The highlighted runs were removed from the results and the sample average was recalculated using the remaining runs. The grain size data can be viewed or downloaded from http://dx.doi.org/10.3133/ofr20141079/ofr1079_data.html. Each data file includes averaged statistics for each sample and the sand-silt-clay ternary diagram generated by GRADISTAT. The unedited output files with statistics for each sample run along with averaged statistics for each sample generated by the USGS Average and Check Standard Deviation macro can be downloaded from http://dx.doi.org/10.3133/ofr20141079/ofr1079_data.html/Grain_Size_Run_Statistics.zip. GRADISTAT calculates statistics for several parameters that do not apply to our dataset or future analyses and therefore are not included in the summarized data files. For example, GRADISTAT also calculates the arithmetic mean grain size of each sample; however, an arithmetic grain-size scale is generally not used in sedimentology because the standard grain-size classifications (Wentworth, 1922) are not based on a normal (Gaussian) distribution, which tends to overemphasize coarse sediment, whereas geometric and their derivative log-normal scales place equal emphasis on the small size differences between fine particles (for example, clay and silt) and the larger size differences between coarse particles (for example, pebbles and cobbles). Other parameters, such as percent gravel, do not apply to this dataset because particles coarser than 1 mm were removed from the samples prior to processing. The averaged results for the subset of statistical parameters that apply to these data are summarized in three spreadsheets, which can be downloaded from http://dx.doi.org/10.3133/ofr20141079/images/Tables/Grain_Size_Data.zip. These metadata are not complete with out the data dictionary (Grain_Size_Data_Dictionary.pdf) also included in this archive, which applies specifically to the summary statistics spreadsheets.
  1. How might this data set be cited?
    Bernier, Julie C., Marot, Marci E., and Adams, C. Scott, 20131201, Sediment Grain size Data from sediment cores Collected from March 2012 to July 2013 along the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Numbers 12BIM01, 12BIM02, 12BIM05m and 13BIM06):.

    Online Links:

    This is part of the following larger work.

    Marot, Marci E., Adams, c. Scott, Richwine, Kathryn A., Smith, Christopher G., Osterman, Lisa E., and Bernier, Julie C., 20131201, Temporal Changes in Lithology and Radiochemistry from the Back-barrier Environments along the Chandeleur Islands, Louisiana: March 2012–July 2013: U.S. Geological Survey Open-File Report 2014-1079, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.835832
    East_Bounding_Coordinate: -88.825012
    North_Bounding_Coordinate: 29.969498
    South_Bounding_Coordinate: 29.895495
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 24-Mar-2012
    Ending_Date: 17-Jul-2013
    Currentness_Reference:
    Ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Tabular digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    The detailed attribute descriptions for the statistics summary workbooks are provided in the included data dictionary (Grain_Size_Data-Dictionary.pdf). These metadata are not complete without this file.
    Entity_and_Attribute_Detail_Citation:
    Data Dictionary for Grain Size Data Tables, in: Marot and others, Temporal Changes in Lithology and Radiochemistry from the Back-barrier Environments along the Chandeleur Islands, Louisiana: March 2012–July 2013: U.S. Geological Survey Open-File Report 2014-1079, http://dx.doi.org/10.3133/ofr20141079.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Julie C. Bernier
    • Marci E. Marot
    • C. Scott Adams
  2. Who also contributed to the data set?
    U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov

Why was the data set created?

The Grain_Size_Data.zip file includes Excel spreadsheets summarizing particle size analysis results from back-barrier wetlands collected on or around the Chandeleur Islands, Louisiana from March 2012 to July 2013 by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center.

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: 2012 (process 1 of 5)
    15 short push cores were collected from the northern Chandeleur Islands in March, July, and September 2012 and July 2013 (USGS Field Activity Numbers 12BIM01, 12BIM02, 12BIM05, and 13BIM06). Samples were transported to the USGS St. Petersburg, FL Coastal and Marine Science Center (SPCMSC) for analysis. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov
    Date: 2012 (process 2 of 5)
    Prior to particle size analysis, organic material was chemically removed for the marsh core samples using 30% hydrogen peroxide (H2O2). The organic matter content in the back-barrier core samples were estimated from the LOI values to be ‹3% and therefore would not interfere with the LS200 measurements. Wet sediment from the marsh samples were dissolved in H2O2 overnight. The H2O2 was then evaporated and the sediment washed and centrifuged twice with deionized water. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov
    Date: 2012 (process 3 of 5)
    Grain-size analyses were performed using a Coulter LS 200 (https://www.beckmancoulter.com/) particle-size analyzer, which uses laser diffraction to measure the size distribution of sediments ranging in size from 0.4 microns to 2 millimeters (mm) (clay to very coarse-grained sand). In order to prevent shell fragments from damaging the LS 200, particles greater than 1 mm in diameter were separated from all samples prior to analysis using a number 18 (1000 microns or 1 mm) U.S. standard sieve, which meets the American Society for Testing and Materials (ASTM) E11 standard specifications for determining particle size using woven-wire test sieves. Two subsamples from each sample were processed through the LS 200 a minimum of three runs each. The LS 200 measures the particle-size distribution of each sample by passing sediment suspended in solution between two narrow panes of glass in front of a laser. Light is scattered by the particles into characteristic refraction patterns measured by an array of photodetectors as intensity per unit area and recorded as relative volume for 92 size-related channels (bins). The size-classification boundaries for each bin were specified based on the ASTM E11 standard. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov
    Date: 2013 (process 4 of 5)
    The raw grain size data were then run through the free software program GRADISTAT (Blott and Pye, 2001; http://www.kpal.co.uk/gradistat), which calculates the mean, sorting, skewness, and kurtosis of each sample geometrically in metric units and logarithmically in phi units (F) (Krumbein, 1934) using the Folk and Ward (1957) method. GRADISTAT also calculates the fraction of sediment from each sample by size category (for example, clay, coarse silt, fine sand) based on a modified Wentworth (1922) size scale. A macro function in Microsoft Excel, developed by the USGS SPCMSC, was applied to the data tocalculate average and standard deviation for each sample set (6 runs per sample), and highlight runs that varied from the set average by more than ±1.5 standard deviations. Excessive deviations from the mean are likely the result of equipment error or extraneous organic material in the sample and are not considered representative of the sample. The highlighted runs were removed from the results and the sample average was recalculated using the remaining runs. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov
    Data sources produced in this process:
    • Grain_Size_Run_Statistics.zip
    Date: 2013 (process 5 of 5)
    The averaged results for all samples, including the number of runs included and the standard deviation of the averaged results were summarized in a series of Excel workbooks for each field activity number and location classification (back-barrier or marsh). Person who carried out this activity:
    U.S. Geological Survey
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 802-5000 (voice)
    mmarot@usgs.gov
    Data sources produced in this process:
    • Grain_Size_Data.zip
  3. What similar or related data should the user be aware of?
    Blott, S.J. and Pye, K., 2001, Gradistat: A grain size distribution and statistics package for the analysis of unconsolidated sediments: Earth Surface Processes and Landforms Volume 26.

    Online Links:

    Other_Citation_Details: Pages 1237-1248

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

  1. How well have the observations been checked?
    The grain size data presented in the run statistics spreadsheets (http://dx.doi.org/10.3133/ofr20141079/images/Tables/Grain_Size_Data.zip) represent the sample averages for a subset of the statistical parameters calculated by GRADISTAT. The number of runs included in the averaged results are also reported, and the standard deviation of the averaged results are reported for most parameters.
  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?
    This is a complete grain size dataset that includes results for 284 sediment samples from 49 push core sites that were collected from the northern Chandeleur Islands in March, July, and September 2012 and July 2013 (U.S. Geological Survey Field Activity Numbers 12BIM01, 12BIM02, 12BIM05, and 13BIM06). During the March 2012 survey, an additional 31 short (< 60 cm), 1-inch-diameter push cores were collected along 10 transects across the berm and natural island; 29 grab samples were collected from the sediment surface along the axis of the berm and adjacent natural island; and 10 grab samples were collected in shallow water north and west of the berm. These samples were collected as part of a complementary USGS CMGP BIER study investigating sediment movement between the berm and the natural island since berm construction. Analyses of those data are described in Bernier and others (2014).
  5. How consistent are the relationships among the observations, including topology?
    The complete grain size dataset including all GRADISTAT parameters, results of individual sample runs, and standard deviations for all sample averages are included in the unedited output files (http://dx.doi.org/10.3133/ofr20141079/images/Tables/Grain_Size_Run_Statistics.zip). Sample runs in the output files for which the mean Folk and Ward grain size varied from the set average by more than 1.5 standard deviations are highlighted in yellow and were not included in final averaged results.

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:
The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Attn: Marci E. Marot
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    mmarot@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable data
  3. What legal disclaimers am I supposed to read?
    This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, 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 imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: This zip archive contains Microsoft Excel workbooks with the grain size summary statistics for sediment samples collected in March, July, and September 2012 and July 2013 (USGS Field Activity Numbers 12BIM01, 12BIM02, 12BIM05, and 13BIM06) and associated metadata. in format Microsoft Excel (version 2010) Tabular data Size: .480
      Network links: http://pubs.usgs.gov/of/2014/1079/images/Tables/Grain_Size_Data.zip
    • Cost to order the data: None, if obtained online

  5. What hardware or software do I need in order to use the data set?
    These workbooks included in this .zip file were created for use with Microsoft Excel 2010. They may also be viewed with the Microsoft Excel viewer or by downloading a Microsoft Compatibility Pack to view with older versions of Microsoft Excel.

Who wrote the metadata?

Dates:
Last modified: 08-Jun-2016
Metadata author:
U.S. Geological Survey
Attn: Marci E. Marot
Geologist
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
mmarot@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/OFR20141079_Grain_Size-met.faq.html>
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