Sediment Grain-size Data from sediment core samples collected in March/April 2014 from Assateague Island and the mainland of Virginia and Maryland (U.S. Geological Survey Field Activity Numbers 2014-301-FA, and 2014-322-FA).

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Frequently anticipated questions:


What does this data set describe?

Title:
Sediment Grain-size Data from sediment core samples collected in March/April 2014 from Assateague Island and the mainland of Virginia and Maryland (U.S. Geological Survey Field Activity Numbers 2014-301-FA, and 2014-322-FA).
Abstract:
The influence of tropical and extratropical cyclones on coastal wetlands and marshes is highly variable in both space and time and depends on a number of climatic, geologic, and physical variables. The impacts storms can be either positive or negative with respect to the wetland and marsh ecosystems. Small to moderate amounts of inorganic sediment added during storms or other events helps to abate pressure from sea-level rise. However, if the volume of sediment is large and the resulting deposits thick, the organic substrate may compact causing submergence and a loss in elevation. Similarly, thick deposits of coarse inorganic sediment may also alter the hydrology of the site and impede vegetative processes. Alternative impacts associated with storms include shoreline erosion at the marsh edge as well as potential emergence. Predicting the outcome of these various responses and potential long-term implications can be obtained from a systematic assessment of both historical and recent event deposits. The objectives of this study are to 1) characterize the surficial sediment of the relict to recent washover fans and back-barrier marshes, and 2) characterize the sediment of 6 marsh cores from the back-barrier marshes and a single marsh island core near the mainland. These geologic data will be integrated with other remote sensing data collected along Assateague Island, Maryland / Virginia and assimilated into an assessment of coastal wetland response to storms.
Supplemental_Information:
Based upon visual inspection, samples with coarse material were dried at a constant 60°C. The dried samples were weighed and then dry-sieved through a number 18 (1000 microns [?m] 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. The two size fractions were weighed and bagged. Grain-size analyses were performed using a Coulter LS200 (https://www.beckmancoulter.com/) particle-size analyzer, which uses laser diffraction to measure the size distribution of sediments ranging in size from 0.4 ?m to 2 mm (clay to very coarse-grained sand). In order to prevent shell fragments from damaging the LS200, particles greater than 1 mm in diameter were separated from all surface sediments (S) and marsh cores samples (M) prior to analysis using a number 18 U.S. standard sieve. If there was sediment > 1 mm, the material was dried and the dry weight was recorded. After the samples were washed through the sieve with filtered city water, a few milliliters of sodium hexametaphosphate solution was added to act as a deflocculant. The sediment slurry was sonicated with a wand sonicator for 30 – 60 seconds before being introduced into the Coulter LS200 to breakdown aggregated particles. The pre-sieved <1 mm dried overwash fan (W) fraction was introduced directly into the Coulter LS200. The raw grain-size data were processed with 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 ({Folk 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 ({Wentworth 1922}) size scale. A macro function in Microsoft Excel, developed by the USGS SPCMSC, was applied to the data to calculate 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 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 with tabs for each core location. 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?
    Smith, Christopher G., Marot, Marci E., Ellis, Alisha M., Wheaton, Cathryn J., Bernier, Julie C., and Adams, C. Scott, 20150501, Sediment Grain-size Data from sediment core samples collected in March/April 2014 from Assateague Island and the mainland of Virginia and Maryland (U.S. Geological Survey Field Activity Numbers 2014-301-FA, and 2014-322-FA).:.

    Online Links:

    This is part of the following larger work.

    Smith, Christopher G., Marot, Marci E., Ellis, Alisha M., Wheaton, Cathryn J., Bernier, Julie C., and Adams, C. Scott, 20150501, Sedimentological and radiochemical characteristics of marsh deposits from Assateague Island and adjacent vicinity, Maryland and Virginia, following Hurricane Sandy: U.S. Geological Survey Open-File Report 2015-1169, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -75.46667
    East_Bounding_Coordinate: -75.11111
    North_Bounding_Coordinate: 38.26667
    South_Bounding_Coordinate: 37.82222
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 26-Mar-2014
    Ending_Date: 30-Oct-2014
    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: Smith and others, Sedimentological and radiochemical characteristics of marsh deposits from Assateague Island and adjacent vicinity, Maryland and Virginia, following Hurricane Sandy: U.S. Geological Survey Open-File Report 2015-1169, http://dx.doi.org/10.3133/ofr20151169.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Christopher G. Smith
    • Marci E. Marot
    • Alisha M. Ellis
    • Cathryn J. Wheaton
    • Julie C. Bernier
    • 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: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

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

Why was the data set created?

The 14CTB_Grain-Size_Data.zip file includes Excel spreadsheets summarizing particle size analysis results from Assateague Island and the mainland of Maryland and Virginia, collected in March/April and October 2014 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: 2014 (process 1 of 5)
    9 cores subsection into 362 surface and subsurface sediment samples were collected from Assateague Island and the Delmarva Peninsula in March/April 2014 (USGS Field Activity Numbers 2014-301-FA, and 2014-322-FA). 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: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@usgs.gov
    Date: 2014 (process 2 of 5)
    Prior to particle size analysis, all marsh core samples (M), peat auger samples (R) and select surficial sediments (S) had organic material chemically removed using approximately 8 mL of 30% hydrogen peroxide (H2O2) overnight. The H2O2 was then evaporated and the sediment was washed and centrifuged twice with deionized water. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@usgs.gov
    Date: 2014 (process 3 of 5)
    Based upon visual inspection, samples with coarse material were dried at a constant 60°C. The dried samples were weighed and then dry-sieved through a number 18 (1000 microns [?m] 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. The two size fractions were weighed and bagged. Grain-size analyses were performed using a Coulter LS200 (https://www.beckmancoulter.com/) particle-size analyzer, which uses laser diffraction to measure the size distribution of sediments ranging in size from 0.4 ?m to 2 mm (clay to very coarse-grained sand). In order to prevent shell fragments from damaging the LS200, particles greater than 1 mm in diameter were separated from all surface sediments (S) and marsh cores samples (M) prior to analysis using a number 18 U.S. standard sieve. If there was sediment > 1 mm, the material was dried and the dry weight was recorded. After the samples were washed through the sieve with filtered city water, a few milliliters of sodium hexametaphosphate solution was added to act as a deflocculant. The sediment slurry was sonicated with a wand sonicator for 30 – 60 seconds before being introduced into the Coulter LS200 to breakdown aggregated particles. The pre-sieved <1 mm dried fraction was introduced directly into the Coulter LS200. Process_Date: 2014 Person who carried out this activity:
    U.S. Geological Survey
    Attn: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@usgs.gov
    Date: 2014 (process 4 of 5)
    The raw grain-size data were processed with 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 ({Folk 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 ({Wentworth 1922}) size scale. A macro function in Microsoft Excel, developed by the USGS SPCMSC, was applied to the data to calculate 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: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@usgs.gov
    Data sources produced in this process:
    • 14CTB_Grain-Size_Data.zip
    Date: 2014 (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 with each core on its own tab. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@usgs.gov
    Data sources produced in this process:
    • 14CTB_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://pubs.er.usgs.gov/publication/ofr20151169/data/14CTB_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 116 surface and 362 subsurface sediment samples sectioned from sediment cores collected on Assateague Island and the Delmarva Peninsula in March/April and October 2014 (U.S. Geological Survey Field Activity Numbers 2014-301-FA, 2014-322-FA).
  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://pubs.er.usgs.gov/publication/ofr20151169/data/14CTB_Grain-Size_Run_Statistics.zip). All samples were measured during extended business hours, ranging from 7:00:00 AM to 6:00:00 PM. Any time stamp observed in the data is within this range. 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: Christopher G. Smith
    Research Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    cgsmith@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 subsurface core sediment samples collected in March/April and October 2014 (USGS Field Activity Numbers 2014-301-FA and 2014-322-FA) and associated metadata. in format Zip archive (version 1) .zip Size: 0.430
      Network links: http://pubs.er.usgs.gov/publication/ofr20151169/data/14CTB_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. The .zip file also contains comma delimited files (.csv) of the grain-size data for surface and subsurface sediments. The .csv data files contains the tabular data in plain text and may be viewed with a standard text editor.

Who wrote the metadata?

Dates:
Last modified: 01-May-2015
Metadata author:
U.S. Geological Survey
Attn: Christopher G. Smith
Research Geologist
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
cgsmith@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/OFR20151169_Grain_Size-met.faq.html>
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