Sedimentologic data and core descriptions from surface samples and sand augers collected in 2023 from the northern Chandeleur Islands, Louisiana

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Frequently anticipated questions:

What does this data set describe?

Title:
Sedimentologic data and core descriptions from surface samples and sand augers collected in 2023 from the northern Chandeleur Islands, Louisiana
Abstract:
In 2023, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) conducted a sediment sampling survey at the northern Chandeleur Islands, Louisiana. Funded by the Extending Government Funding and Delivering Emergency Assistance Act (Public Law 117-43) enacted on September 30, 2021, these data complement sediment data from samples previously collected from the Chandeleur Islands in 2007, 2008, 2012, 2013, and 2015.
Supplemental_Information:
Data were collected during USGS FAN 2023-307-FA; two subFANs (23BIM03 and 23BIM04) were used to differentiate samples collected by separate field teams. Additional survey and data details are available from the U.S. Geological Survey Coastal and Marine Geoscience Data System (CMGDS) at https://cmgds.marine.usgs.gov/services/activity.php?fan=2023-307-FA.
  1. How might this data set be cited?
    Bernier, Julie C., Everhart, Cheyenne S., and Miselis, Jennifer L., 20250626, Sedimentologic data and core descriptions from surface samples and sand augers collected in 2023 from the northern Chandeleur Islands, Louisiana:.

    This is part of the following larger work.

    Bernier, Julie C., Everhart, Cheyenne S., and Miselis, Jennifer L., 20250626, Sediment Data From Surface Samples and Sand Augers Collected in 2023 From the Northern Chandeleur Islands, Louisiana: U.S. Geological Survey data release doi:10.5066/P13KRKA4, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.91468
    East_Bounding_Coordinate: -88.79994
    North_Bounding_Coordinate: 30.06997
    South_Bounding_Coordinate: 29.74132
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 24-Mar-2023
    Ending_Date: 31-Mar-2023
    Currentness_Reference:
    ground condition
  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 Vector data set. It contains the following vector data types (SDTS terminology):
      • String (200)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -75.0
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000.0
      False_Northing: 0.0
      Planar coordinates are encoded using Coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.001
      Ordinates (y-coordinates) are specified to the nearest 0.001
      Planar coordinates are specified in Meters
      The horizontal datum used is North American Datum 1983.
      The ellipsoid used is Geodectic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum 1988
      Altitude_Resolution: 0.001
      Altitude_Distance_Units: meter
      Altitude_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    2023-307-FA_SampleSites.xslx, 2023-307-FA_SampleSites.csv, 2023-307-FA_SampleSites.shp, 2023-307-FA_SampleSites.kml
    File containing the site locations and sample information for 2023-307-FA surface samples and sand augers. Files are provided in Microsoft Excel (.xlsx), comma-separated values (.csv), Esri shapefile (.shp), and Keyhole Markup Language (KML) formats, and a sample location map (2023-307-FA_SampleSites.jpg) is also provided in Joint Photographic Experts Group (JPEG) format in the file 2023-307-FA_SampleSites.zip. (Source: USGS)
    FID
    Internal feature number (Source: Esri) Sequential unique whole numbers that are automatically generated. Attribute included only in the shapefile.
    Shape
    Feature geometry (Source: Esri) Geometry type defining the features. Attribute included only in the shapefile.
    FAN
    Field Activity Number (Source: USGS) Character string representing the FAN (2023-307-FA) for this survey.
    SampleID
    Sample identification number (Source: USGS) Character string using the following convention: 23BIM03-## or 23BIM04-###, where 23BIM03 and 23BIM04 are subFANs assigned to separate field teams and ## (###) is the unique sample number. For example, 23BIM03-01; 23BIM04-001.
    SampleType
    Sample type (Source: USGS)
    ValueDefinition
    sand augerPush core collected using an AMS, Inc. sand/loose sediment soil probe.
    surface grabSurface sample collected using a scoop (samples collected on the emergent island or in shallow intertidal areas).
    ponarSurface sample collected using a Petit Ponar grab sampler deployed from a skiff or boat (submerged samples collected from water depths greater than about 1 m).
    SampleEnv
    Localized description of site location. (Source: USGS) Character string describing the barrier environment from which the sample was collected.
    Date_Coll
    Date the core was collected, written as MM/DD/YYYY (2-digit month, 2-digit day, 4-digit year). (Source: USGS)
    Range of values
    Minimum:03/24/2023
    Maximum:03/31/2023
    NAD83_Lon
    Longitude of site location, in decimal degrees (NAD83). (Source: USGS)
    Range of values
    Minimum:-88.91468
    Maximum:-88.79994
    Units:Decimal degrees
    Resolution:0.00001
    NAD83_Lat
    Latitude of site location, in decimal degrees relative to the North American Datum of 1983 (NAD83). (Source: USGS)
    Range of values
    Minimum:29.74132
    Maximum:30.06997
    Units:Decimal degrees
    Resolution:0.00001
    NAD83_X
    X-coordinate (easting) of site location, in meters (NAD83, Universal Transverse Mercator Zone 16 North [UTM 16N]). (Source: USGS)
    Range of values
    Minimum:314882.442
    Maximum:326298.68
    Units:Meters
    Resolution:0.001
    NAD83_Y
    Y-coordinate (northing) of site location, in meters (NAD83, UTM Zone 16 N). (Source: USGS)
    Range of values
    Minimum:3291579.808
    Maximum:3328016.602
    Units:Meters
    Resolution:0.001
    Source1
    Location information data source (Source: USGS)
    ValueDefinition
    DGPSLocation (position) derived from post-processed DGPS.
    GPSLocation (position) information recorded at the time of sample collection using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS.
    NAVD88_G18
    Elevation (orthometric height) of site location, in meters relative to the North American Vertical Datum of 1988 (NAVD88) defined using the GEOID18 geoid model. A value of -9999 indicates no elevation data are available. (Source: USGS)
    Range of values
    Minimum:-8.718
    Maximum:1.593
    Units:Meters
    Resolution:0.001
    Source2
    Elevation information data source (Source: USGS)
    ValueDefinition
    DGPSElevation derived from post-processed DGPS.
    lidarElevation interpolated from lidar data collected in October 2022 (OCM Partners, 2025).
    SBESElevation interpolated from SBES data collected in June and August, 2023 (Lyons and others, 2025).
    MBESElevation interpolated from MBES data collected in June and August, 2023 (Stalk and others, 2025).
    2023-307-FA_CoreLogs.zip
    File containing descriptive logs for each core in JPEG format. Credit, contact information, copyright, usage terms, image descriptions, attribution url, metadata link, and georeferencing information were added to EXIF header of each core log image using ExifTool. Please view the imagery headers for the image metadata. (Source: USGS)
    2023-307-FA_CorePhotos.zip
    File containing high-resolution photos of each core in JPEG format. Credit, contact information, copyright, usage terms, image descriptions, attribution url, metadata link, and georeferencing information were added to the EXIF header of each core log image using ExifTool. Please view the imagery headers for the image metadata. (Source: USGS)
    2023-307-FA_CoreXRays.zip
    File containing high-resolution x-rays of each sand auger section in Tagged Image File Format (TIFF) format. Credit, contact information, copyright, usage terms, image descriptions, attribution url, metadata link, and georeferencing information were added to the EXIF header of each core log image using ExifTool. Please view the imagery headers for the image metadata. (Source: USGS)
    2023-307-FA_GrainSize_SumStats.xlsx, 2023-307-FA_Cores_GrainSize_SumStats.csv, 2023-307-FA_Surface_GrainSize_SumStats.csv
    Summary LS13 320 grain-size data for surface and sand auger sediment samples. Files are provided in Microsoft Excel (.xlsx) and comma-separated values (.csv) formats. The averaged results for all samples, including the number of runs used, and the standard deviation of the averaged results are provided. Samples for which the percent bulk dry weight of the >1 mm fraction was not measured are denoted with a (-). For full entity and attribute details, please refer to the accompanying data dictionary, 2023-307-FA_GrainSize_DataDictionary.docx, included in the file 2023-307-FA_GrainSizeData.zip. 2023-307-FA_GrainSize_SumStats.xlsx contains a copy of the data dictionary as well as the summary LS13 320 data organized by sample type and subFAN. (Source: USGS)
    2023-307-FA_GrainSizeDistributions.xlsx, 2023-307-FA_Cores_GrainSizeDistributions.csv, 2023-307-FA_Surface_GrainSizeDistributions.csv
    Grain-size distribution data for each sample listing the class weight retained in each aperture bin as a percent of the total sample weight. Results are the average of 8 runs per sample for most samples. Files are provided in Microsoft Excel (.xlsx) and comma-separated values (.csv) formats. (Source: USGS)
    Aperture_microns
    Coulter software bin aperture, in microns (Source: Beckman Coulter LS13 320 Software)
    Range of values
    Minimum:0.375
    Maximum:2000
    MedianDiameter_microns
    Median of Coulter software bin aperture, in microns (Source: Beckman Coulter LS13 320 Software)
    Range of values
    Minimum:0.3935
    Maximum:1911
    23BIM03-20_14CData.xlsx, 23BIM03-20_14CData.csv
    File containing the results of radiocarbon analyses for 2023-307-FA sand auger 23BIM03-20 subsamples. For full entity and attribute details, please refer to the accompanying data dictionary, 23BIM03-20_14C_DataDictionary.docx, included in the file 23BIM03-20_14CData.zip. Files are provided in Microsoft Excel (.xlsx) and comma-separated values (.csv) formats. (Source: USGS, Beta Analytic, Inc.)
    Entity_and_Attribute_Overview:
    The detailed attribute descriptions for the grain-size summary statistics and the radiocarbon analyses are provided in the data dictionaries 2023-307-FA_GrainSize_DataDictionary.docx and 23BIM03-20_14CDataDictionary.docx included in the files 2023-307-FA_GrainSizeData.zip and 23BIM03-20_14CData.zip, respectively. These metadata are not complete without these files.
    Entity_and_Attribute_Detail_Citation:
    Entity and attribute information was generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

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
    • Cheyenne S. Everhart
    • Jennifer L. Miselis
  2. Who also contributed to the data set?
    Funding and (or) support for this study were provided as part of the Extending Government Funding and Delivering Emergency Assistance Act (Public Law 117-43), enacted on September 30, 2021. The authors thank Nancy DeWitt, Andrew Farmer (USGS SPCMSC), and Erin Lyons (Cherokee Nation System Solutions contracted to USGS) for their assistance with data collection. This document was improved by scientific and metadata reviews by Noreen Buster (USGS SPCMSC) and Tess Rivenbark-Terrano (Cherokee Nation System Solutions contracted to USGS).
  3. To whom should users address questions about the data?
    U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
    Attn: Julie C. Bernier
    Geologist
    600 4th Street South
    St. Petersburg, FL

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

Why was the data set created?

This data release serves as an archive of sedimentologic data from surface samples and sand-auger cores collected from terrestrial and submerged barrier environments at the northern Chandeleur Islands, Louisiana from March 24-31, 2023 (USGS Field Activity Number [FAN] 2023-307-FA). Grain-size data from surface samples are provided to characterize the surficial sediment texture of back-barrier, island, and shoreface environments. Sedimentologic data from sand augers, including descriptive core logs and grain-size data, are provided to characterize the shallow subsurface stratigraphy at selected sites. Data acquisition and processing methods follow procedures described in Bernier and others (2014, 2023).

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: 2023 (process 1 of 8)
    Sample collection- Sand augers were collected using an AMS, Inc. sand/loose sediment soil probe, which can accommodate a 2.54 centimeter (cm) (1 inch) diameter by approximately 96 cm (3 feet) plastic sleeve. After extraction, each core was capped, sealed, and labeled with the core number and orientation. All cores were transported to the SPCMSC sediment laboratory for processing and analysis. Surface samples were collected using (a) a scoop for samples collected on the emergent island or shallow intertidal areas or (b) a WILDCO Petit Ponar grab sampler deployed from a skiff or boat for submerged samples collected from water depths greater than about 1 m. Position and elevation data at each sand auger site and selected surface sample sites were recorded using a Spectra Precision SP80 DGPS receiver and geodetic antenna recording full-carrier-phase positioning signals from satellites at a rate of 1 second (s). Raw data were recorded for a minimum of 5 minutes. DGPS data were recorded concurrently throughout the survey at a nearby base station established at MRK3 using a Spectra Precision SP90M DGPS receiver and Trimble Zephyr-3 Base antenna. Position data at the remaining sample sites were recorded at the time of collection using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS. Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Date: 2024 (process 2 of 8)
    Navigation Processing- Base station data were post-processed through the NGS OPUS and the time-weighted coordinates calculated from all base-station occupations at MRK3 were used for post-processing. The base station coordinates were imported into GrafNav and, for DGPS sites, the data from the rover GPS were post-processed to the concurrent base-station session data. The final, differentially corrected, GPS positions for each rover session were processed and exported in the North American Datum of 1983 (NAD83) (2011) coordinate system and processed orthometric elevations are reported relative to the North American Vertical Datum of 1988 (NAVD88), derived using the GEOID18 geodetic model. For samples locations recorded using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS, sample elevations were subsequently interpolated from lidar data collected in October 2022 (OCM Partners, 2025) or SBES and MBES data collected in June and August, 2023 (Lyons and others, 2025; Stalk and others, 2025). Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Data sources produced in this process:
    • 2023-307-FA_SampleSites.zip
    Date: 2024 (process 3 of 8)
    Sand auger processing- At the SPCMSC sediment laboratory, each sand auger section was split lengthwise, photographed, x-rayed, described macroscopically using standard sediment-logging methods, and subsampled for grain-size analysis. The split sand augers were photographed in approximately 30-cm overlapping segments with a Nikon D3500 digital camera with an 18- to 55-mm zoom lens using consistent (manually programmed) settings with autofocus from a fixed height. The raw images were white-balanced using GIMP software, cropped to the same extent (to remove areas outside of the core barrel), and "stitched" together using The Panorama Factory software, providing seamless high-resolution whole-core images exported as Joint Photographic Experts Group (JPEG) format. Core x-rays were acquired using an Ecotron EPX-2800 x-ray unit at 85 kilovolts for 16 milliampere-seconds from a height of 79 cm. Each x-radiograph was captured on an 11 × 14-inch phosphor cassette, which was scanned on an iCRco, Inc., iCR3600+ scanner at 254 pixels per inch and exported as a 16-bit Tagged Image File Format (TIF) image. The raw x-radiographs show a slight anode heel effect, which is a variation in x-ray intensity along the anode-cathode axis that results in non-uniform pixel intensity across the image. This effect was corrected by subtracting a background pixel intensity template from each raw image (Bernier and others, 2014). The images were cropped (to the same extent and to remove areas outside of the cassette), background image subtracted, and grayscale color inversion was applied using ImageJ software. Depending on core length, sand augers that did not fit onto the phosphor cassette were x-rayed in "top" and "bottom" or "top," "middle," and "bottom" segments and then merged in Adobe Illustrator. Textural descriptions for the core logs are based on macroscopic observations. Sediment color is based on the Munsell soil color system (https://munsell.com/color-products/color-communications-products/environmental-color-communication/munsell-soil-color-charts/). Descriptive core logs were compiled using Rockware LogPlot software. Samples consisted of 3-cm sections sampled at varying intervals down-core based on observed sedimentologic changes. Two samples from core 23BIM03-20 collected for radiocarbon dating and were sealed, labeled, and shipped to Beta Analytic, Inc. for analysis. Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Data sources produced in this process:
    • 2023-307-FA_CorePhotos.zip
    • 2023-307-FA_CoreXRays.zip
    • 2023-307-FA_CoreLogs.zip
    Date: 2024 (process 4 of 8)
    Grain-size PSA analysis- At the SPCMSC sediment laboratory, grain-size analyses were performed using a Coulter LS13 320 (https://www.beckmancoulter.com/) PSA. The LS13 320 uses laser diffraction to measure the size distribution of sediments from 0.4 µm to 2 mm, encompassing clay to very coarse-grained sand. To prevent large shell fragments from damaging the instrument, particles greater than 1 mm in diameter (coarse sand) were separated from all samples prior to analysis using a number 18 (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. Prior to processing through the LS13 320, samples with visually observed organic content were digested in 30% hydrogen peroxide (H2O2) to remove excess organic material; six samples were analyzed both undigested and digested for comparison. Following SPCMSC standard procedures, samples were (a) dried at 60 degrees Celsius and dry loaded into the LS13 320 (well-sorted sandy sediment) or (b) homogenized in water and sonicated to suspend in solution prior to transferring to the LS13 320 (sediment with visually observed mud content or samples that were previously digested with H2O2). Two subsamples from each sample were processed through the instrument a minimum of four runs each. Once introduced into the LS13 320, the sediment in the sample well was sonicated with a sonicator wand for 30 to 60 seconds to separate any aggregates before starting the first run for both subsamples. The LS13 320 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). Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Date: 2024 (process 5 of 8)
    Grain-size processing- For samples that were dry loaded into the LS13 320, sediment >1 mm in diameter was reported as a percent fraction of the total bulk dry weight of each sample (bulk dry weights were not measured for samples loaded in solution). The raw PSA grain-size data were run through the free software GRADISTAT version 9, (Blott and Pye, 2001; kpal.co.uk/gradistat), which calculates the mean, sorting, skewness and kurtosis of each sample geometrically, in metric units, and logarithmically, in phi (Φ) units (Krumbein, 1934), using the Folk and Ward (1957) scale. GRADISTAT also reports the descriptive sediment texture after Folk (1954) and 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 to calculate average and standard deviation for each sample set (8 runs per sample), and highlight runs that varied from the set average by more than ±1.5 standard deviations. The highlighted runs were removed from the results and the sample average was recalculated using the remaining runs. The averaged results for all samples and the number of averaged runs are included in an Excel workbook, organized by subFAN, and comma-separated values (.csv) data files, organized by sample type (core or surface sample). The raw LS13 320 output files, which list the class weight retained in each aperture bin as a percent of the total sample weight for each sample run, were compiled by GRADISTAT, imported into Matlab, and averaged for each sample (8 runs per sample except for samples with runs flagged and removed as described above); those grain-size distribution data are also included in this data release for advanced users. Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Data sources produced in this process:
    • 2023-307-FA_GrainSize_SumStats.xlsx
    • 2023-307-FA_Cores_GrainSize_SumStats.csv
    • 2023-307-FA_Surface_GrainSize_SumStats.csv
    • 2023-307-FA_GrainSizeDistributions.xlsx
    • 2023-307-FA_Cores_GrainSizeDistributions.csv
    • 2023-307-FA_Surface_GrainSizeDistributions.csv
    Date: 2025 (process 6 of 8)
    Grain-size plots- The down-core grain-size distributions (>1 mm fraction, coarse sand, medium sand, fine sand, very fine sand, and mud classes) for each sand auger were plotted in Matlab and exported as a JPEG image; cores are arranged from north (top) to south (bottom) of image. The sediment texture for all samples were also plotted in Matlab on a ternary diagram using the Folk (1954) fine sediment classification and exported as a JPEG image. Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
    Data sources produced in this process:
    • 2023-307-FA_Cores_GrainSizeDistributions.jpg
    • 2023-307-FA_GrainSize_TernaryPlot.jpg
    Date: 2023 (process 7 of 8)
    Radiocarbon dating- Both the organic sediment fraction and plant material from two organic-rich subsamples from core 23BIM03-20 were analyzed using accelerated mass spectrometry (AMS) radiocarbon (14C) dating at Beta Analytic, Inc. (Miami, Florida). For each sample, the conventional 14C radiocarbon age as well as calibrated age ranges are reported. Calibrated ages are based on terrestrial calibration curves from INTCAL20 (Reimer and others, 2020) using the High Probability Density (HPD) Range Method (Bronk Ramsey, 2009). For additional information on understanding calibrated radiocarbon ages, refer to the Beta Analytic, Inc. (https://www.radiocarbon.com/calendar-calibration-carbon-dating.htm) or University of Oxford Radiocarbon Accelerator Unit (https://c14.arch.ox.ac.uk/calibration.html, https://c14.arch.ox.ac.uk/explanation.php) websites. Person who carried out this activity:
    Beta Analytic, Inc.
    Beta Analytic, Inc.
    4985 SW 74th Court
    Miami, FL

    (305) 667-5167 (voice)
    lab@radiocarbon.com
    Data sources produced in this process:
    • 23BIM03-20_14CData.xlsx
    • 23BIM03-20_14CData.csv
    Date: 2025 (process 8 of 8)
    Populating image headers- Credit, contact information, copyright, usage terms, image descriptions, attribution url, metadata link, and georeferencing information were added to the exchangeable image file format (EXIF) header of each image using Phil Harvey’s ExifTool. The images were grouped by image type (core logs, photographs, and x-rays) into separate folders: 2023-307-FA_CoreLogs, 2023-307-FA_CorePhotos, and 2023-307-FA_CoreXRays. All information in the scripts were the same among all images, aside from the EXIF:ImageDescription, EXIF:DateTimeOriginal, EXIF:GPSLatitude and EXIF:GPSLongtitude information, as that information varies for each core. A separate script containing the core-specific header information was run on each image individually to populate those headers. The core logs and photographs are published as JPGs, whereas the core x-rays are published as TIFs. Therefore, all mentions of the file extension in the example scripts below used ".TIF" rather than ".JPG" for the x-ray images. Image header information was also populated for the files 2023-307-FA_Cores_GrainSizeDistributions.jpg and 2023-307-FA_GrainSize_TernaryPlot.jpg in 2023-307-FA_GrainSizeData.zip. However, since these image details grain-size data for all samples, the EXIF:GPSMapDatum, EXIF:GPSAreaInformation, and core-specific headers were not added.
    First, the following command was run on all images in a folder to preserve filenames: exiftool -P "-XMP:PreservedFileName<Filename" *.jpg
    Second, the following command was run on all images in a folder to populate the first set of headers. exiftool -IPTC:Credit="U.S. Geological Survey" -IPTC:Contact="gs-g-spcmsc_data_inquiries@usgs.gov" -EXIF:Copyright="Public Domain" -XMP:UsageTerms="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." -XMP:AttributionURL="https://doi.org/10.5066/P13KRKA4" -XMP:Event="2023-307-FA" -EXIF:GPSAreaInformation="Location of core collection site, GPS coordinates are in NAD83" -XMP:ExternalMetadataLink="https://www1.usgs.gov/pir/api/identifiers/USGS:4e67da86-b79a-4666-984b-5fb89ee580c8" -EXIF:GPSMapDatum="NAD83" *.jpg
    Third, the following command was run on each image in the folder to populate the unique image headers for each core. This command called on a .csv file “23BIM03_CorePhotos_ExifHeaders.csv") containing the image file name, image description, core collection date, GPS latitude, and GPS longitude of each core. exiftool -csv='23BIM03_CorePhotos_ExifHeaders.csv' *.jpg
    Fourth, the following command run on all images in a folder to copy information into duplicate tags: exiftool -P "-XMP-photoshop:Credit<IPTC:Credit" "-XMP-iptcCore:CreatorWorkEmail<IPTC:Contact" "-XMP-dc:Rights<EXIF:Copyright" "-XMP-dc:Description<EXIF:ImageDescription" "-XMP-exif:all<GPS:all" "-XMP-photoshop:DateCreated<EXIF:DateTimeOriginal" "-EXIF:GPSDateStamp<EXIF:DateTimeOriginal" -overwrite_original *.JPG
    To extract the information from the image headers using ExifTool, run the following command after connecting to the unzipped folder containing the images: exiftool a.jpg, where 'a' is replaced with the filename (example: 23BIM03-13_Stitched.jpg) Person who carried out this activity:
    Julie C. Bernier
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jbernier@usgs.gov
  3. What similar or related data should the user be aware of?
    Bernier, Julie C., Everhart, Cheyenne S., Ciarletta, Daniel C., Miselis, Jennifer L., and DeWitt, Nancy T., 20230502, Sediment data from vibracores and sand augers collected in 2021 and 2022 from Fire Island, New York: U.S. Geological Survey data release doi:10.5066/P91P1T88, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    Bernier, Julie C., Kelso, Kyle W., Buster, Noreen A., Flocks, James G., Miselis, Jennifer L., and DeWitt, Nancy T., 2014, Sediment data collected in 2012 from the northern Chandeleur Islands, Louisiana: U.S. Geological Survey Data Series 850, U.S. Geological Survey, Reston, VA.

    Online Links:

    Coulter, Beckman, 201110, LS 13 320 laser diffraction particle size analyzer.

    Online Links:

    Blott, Simon J., and Pye, Kenneth, 20010928, GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments: Earth Surface Processes and Landforms Volume 26, Issue 11.

    Online Links:

    Other_Citation_Details: Pages 1237-1248
    Partners, OCM, 2025, 2022 USGS Topobathy Lidar: Breton Island, LA.

    Online Links:

    Lyons, Erin O., Stalk, Chelsea A., Miselis, Jennifer L., Buster, Noreen A., Bernier, Julie C., and DeWitt, Nancy T., 20250325, Coastal single-beam bathymetry data collected in 2023 from the Chandeleur Islands, Louisiana: U.S. Geological Survey data release doi:10.5066/P1HJAVAR, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

    Online Links:

    Stalk, Chelsea A., Bemelmans, Christopher C., and Miselis, Jennifer L., 20250325, Coastal bathymetry and backscatter data collected June-August 2023 from the Chandeleur Islands, Louisiana: U.S. Geological Survey data release doi:10.5066/P1NWHXZS, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

    Online Links:

    Folk, Robert L., and Ward, William C., 19570301, Brazos River bar: A study in the significance of grain size parameters: Journal of Sedimentary Petrology Volume 27, No. 1.

    Online Links:

    Other_Citation_Details: Pages 3-26
    Krumbein, William C., 19340801, Size frequency distributions of sediments: Journal of Sedimentary Petrology Volume 4, No. 2.

    Online Links:

    Other_Citation_Details: Pages 65-77
    Wentworth, Chester K., 1922, A scale of grade and class terms for clastic sediments: Journal of Geology Volume 30, No. 5.

    Online Links:

    Other_Citation_Details: Pages 377-392
    Folk, Robert L., 195407, The distinction between grain size and mineral composition in sedimentary-rock nomenclature: Journal of Geology Volume 62, No. 4.

    Online Links:

    Other_Citation_Details: Pages 344-359
    Ramsey, Christopher Bronk, 2009, Bayesian analysis of radiocarbon dates: Radiocarbon Volume 51, Issue 1.

    Online Links:

    Other_Citation_Details: Pages 337-360
    Reimer, Paula J., and others, and, 20200812, The IntCal20 northern hemisphere radiocarbon age calibration curve (0–55 cal kBP): Radiocarbon Volume 62, Issue 4.

    Online Links:

    Other_Citation_Details: Pages 725-757

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

  1. How well have the observations been checked?
    The positional accuracy of the sample locations is determined by the method of coordinate derivation: (a) Differential Global Positioning System (DGPS) coordinates obtained by post-processing raw position data recorded at time of collection using NGS OPUS and NovAtel GrafNav software packages or (b) GPS coordinates recorded at time of collection using a handheld or boat-mounted GPS. Due to the assumption of grain sphericity of the Fraunhofer optical model used by the Coulter LS13 320 particle-size analyzer (PSA) for grain-size analysis, angular particles are measured by their longest axis (Beckman Coulter, 2011). When enough thin, angular material is present, the LS13 320 output files often report a percentage of the grain size distribution within the 1-2 millimeter (mm) fraction, despite all samples being sieved at 1 mm before analysis. The grain-size data represent the sample averages for a subset of the statistical parameters calculated by GRADISTAT (Blott and Pye, 2001). The number of runs included in the averaged results are reported, and the standard deviation of the averaged results are reported for most parameters. A secondary data review determined that all grain-size data reported met the laboratory’s quality control requirements. Beckman Coulter control standards G15 (15 microns [µm]) and GB500 (500 µm) were analyzed on the Coulter LS13 320 particle-size analyzer before all sediment samples were analyzed to validate instrument performance (Beckman Coulter, 2011). In addition to processing the samples submitted for radiocarbon dating, Beta Analytic, Inc. also analyzes known-value reference materials. All quality assurance measurements passed the internal acceptance tests.
  2. How accurate are the geographic locations?
    Position and elevation associated with each DGPS site was determined by post-processed differential correction of the base/rover setup using NovAtel's GrafNav software. The base station used for control during this survey, stamped MRK3, was installed by the USGS in 2015 at the northern Chandeleur Islands east of Schooner Harbor and is not in the NGS database with an associated Permanent Identifier (PID). The coordinate values of the MRK3 were derived from the time-weighted average of session values obtained from NGS OPUS. The estimated horizontal accuracy (2-sigma) of the post-processed base coordinates for MRK3 is +/- 0.00017 degrees latitude and +/- 0.00017 degrees longitude. Differential processing of the full-carrier phase data in GrafNav allows precise positioning of the base and rover receivers and improves the rover positions by assessing positional errors computed at the base receiver and applying those errors or differences to the rover receiver. Forward and backward time-series processing of the rover data provides an independent calculation of the baseline trajectory and rover position relative to the base station; the positional accuracy can be estimated by differencing the time series (position separation). The estimated post-processed horizontal accuracy (2-sigma) for all rover data to the MRK3 base station was 0.007 +/- 0.005 meters (m). For samples locations recorded using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS, the manufacturer's specified accuracy is 3 to 5 meters (95% typical).
  3. How accurate are the heights or depths?
    As described above, position and elevation associated with each DGPS site was determined by post-processed differential correction. The estimated vertical accuracy (2-sigma) of the post-processed base coordinates for MRK3 is +/- 0.012 m. The estimated post-processed vertical accuracy (2-sigma) for all rover data to the MRK3 base station was 0.012 +/- 0.009 m. For samples locations recorded using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS, the vertical accuracy is dependent on the vertical accuracy of the source lidar, SBES, and MBES elevation data (OCM Partners, 2025; Lyons and others, 2025; Stalk and others, 2025).
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented. Data release doi:10.5066/P13KRKA4 includes the geographic locations; site elevations; core descriptions, core photos, and core x-rays (when applicable); and grain-size data from 10 sand-auger cores and 190 surface samples collected from the northern Chandeleur Islands, Louisiana, March 24-31, 2023 (USGS FAN 2023-307-FA). Radiocarbon ages for the plant material and organic sediment fractions for 2 samples from core 23BIM03-20 are also provided.
  5. How consistent are the relationships among the observations, including topology?
    Position and elevation data at each core site and selected surface sample sites were recorded with a Spectra Precision SP80 DGPS receiver and geodetic antenna. DGPS data were recorded concurrently throughout the survey at a nearby base station using a Spectra Precision SP90M DGPS receiver and Trimble Zephyr-3 Base antenna. The average baseline distance for DGPS sites was 7.0 +/- 4.9 kilometers (km) (1-sigma) and the maximum baseline distance was 20.6 km. Position data at the remaining sample sites were recorded at the time of collection using a Garmin GPSMap 79SC handheld GPS or Garmin Echomap UHD 64cv boat-mounted GPS, and sample elevations were subsequently interpolated from temporally similar lidar (OCM Partners, 2025), single-beam echosounder (SBES; Lyons and others, 2025) or multibeam echosounder (MBES, Stalk and others, 2025) datasets. Grain-size sample runs in the GRADISTAT output files for which the mean Folk and Ward (1957) grain-size varied from the set average by more than 1.5 standard deviations 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 No access constraints. Please see 'Distribution Information' for details.
Use_Constraints These data are marked with a Creative Common CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
    Attn: USGS SPCMSC Data Management
    600 4th Street South
    St. Petersburg, FL
    United States

    727-502-8000 (voice)
    gs-g-spcmsc_data_inquiries@usgs.gov
  2. What's the catalog number I need to order this data set?
  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?
  5. What hardware or software do I need in order to use the data set?
    All spreadsheets were created in Microsoft Excel; these data are also provided as comma-separated values (.csv) text files. Core locations are also provided as GIS data files in Esri shapefile (.shp) and Keyhole Markup Language (KML) formats; these files can be opened using the free Google Earth (https://www.google.com/earth/) GIS viewer. Core logs, core photos, and grain-size distribution plots are provided in Joint Photographic Experts Group (JPEG) format and core x-rays are provided in Tagged Image File Format (TIFF) format. Image metadata (exif image headers) for the JPEG and TIFF images can be read using Phil Harvey’s ExifTool (https://exiftool.org/).

Who wrote the metadata?

Dates:
Last modified: 26-Jun-2025
Metadata author:
U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
Attn: USGS SPCMSC Data Management
600 4th Street South
St. Petersburg, FL
United States

727-502-8000 (voice)
gs-g-spcmsc_data_inquiries@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/2023-307-FA_Sediment_metadata.faq.html>
Generated by mp version 2.9.51 on Fri Jun 27 10:15:24 2025