South Florida mangrove peat radiocarbon metadata

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Frequently anticipated questions:

What does this data set describe?

Title: South Florida mangrove peat radiocarbon metadata
Abstract:
In 2016, U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) researchers and academic collaborators collected cores of mangrove peat from two islands in the Florida Keys: Snipe Key (24.679°N, 81.653°W) and Swan Key (25.349°N, 80.251°W). This data release contains the radiocarbon ages and associated data for peat samples analyzed throughout the two cores (SNK-16-C1 and SBC-16-C10).
Supplemental_Information:
The cores collected were assigned a Field Activity Number (FAN), 2016-344-FA. FANs are unique identifiers assigned by the USGS to provide more information about the activities conducted in the field for a study. Please visit the Coastal and Marine Geoscience Data System (CMGDS) field activity webpage for more information about the FAN related to this dataset, https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-344-FA.
  1. How might this data set be cited?
    Khan, Nicole S., and Toth, Lauren T., 20220706, South Florida mangrove peat radiocarbon metadata:.

    This is part of the following larger work.

    Khan, Nicole S., Toth, Lauren T., Moyer, Ryan P., Shaw, Jaimie E., Capar, Paulina, Kemp, Andrew C., Engelhart, Simon E., and Horton, Benjamin P., 20220706, Mangrove Peat Radiocarbon Ages From Snipe and Swan Key, FL: U.S. Geological Survey data release doi:10.5066/P9OOL3L4, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -81.653
    East_Bounding_Coordinate: -80.251
    North_Bounding_Coordinate: 25.349
    South_Bounding_Coordinate: 24.679
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2016
    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?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (91)
    2. What coordinate system is used to represent geographic features?
  7. How does the data set describe geographic features?
    Snipe_and_Swan_Key_mangrove_peat_radiocarbon_data.csv, Snipe_and_Swan_Key_mangrove_peat_radiocarbon_data.xlsx
    Sample description and radiocarbon data from mangrove peat cores collected at Snipe Key and Swan Key, Florida. (Source: USGS)
    Core ID
    A unique identifier (ID) for the two cores analyzed in this study. (Source: USGS) The core ID is a combination of the site where the core was collected (Snipe Key=SNK, Swan Key=SBC), the year the cores were collected (2016), and the core number (Snipe Key Core #1=C1, Swan Key Core #10=C10).
    Accession Number
    A unique identifier for each sample assigned by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) radiocarbon laboratory. (Source: NOSAMS (https://www2.whoi.edu/site/nosams/))
    Range of values
    Minimum:OS-126725
    Maximum:OS-138073
    Units:sample number
    Depth in core (cm)
    The depth in centimeters (cm) from the top of each core where each sample was collected. (Source: USGS)
    Range of values
    Minimum:8.5
    Maximum:750.5
    Units:centimeters (cm)
    Sample type
    The type of peat material (Bulk=bulk peat sample, Macro=macrofossil of mangrove wood) that was sampled for radiocarbon dating. (Source: USGS)
    ValueDefinition
    BulkThe fine-fraction of bulk mangrove peat (<63 micron) was sampled from the core for radiocarbon dating.
    MacroPlant macrofossils of mangrove wood (trunk or branches), terminal stems, or prop root bark were sampled from the core for radiocarbon dating.
    Process
    The method (process) used by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) radiocarbon laboratory to determine the radiocarbon ages of the samples. (Source: USGS)
    ValueDefinition
    (OC) Organic CarbonThis process is used for plant/wood and charcoal samples. These samples first undergo a series of acid-base-acid leaches to remove inorganic carbon and mobile organic acid phases. After that pre-treatment, the organic carbon samples are combusted at a high temperature to produce carbon dioxide for radiocarbon analysis.
    (GS) Gas SampleThese samples are submitted to NOSAMS as ampoules of carbon dioxide. Those ampoules are cracked, quantified, split (if required), and transferred to a reaction tube for reduction to pure carbon. The carbon dioxide is reduced with use of a catalyst (iron or cobalt) in the presence of excess hydrogen.
    F modern
    F modern=Fraction modern, which is a measurement of the deviation of the carbon-14 to carbon-12 (14C/12C) ratio of a sample from “Modern.” Modern is defined as 95% of the radiocarbon concentration (in 1950 C.E.). (Source: NOSAMS (https://www2.whoi.edu/site/nosams/))
    Range of values
    Minimum:0.5049
    Maximum:1.2058
    Units:a unitless ratio
    F modern uncertainty
    The uncertainty in the determination of the deviation of a sample's radiocarbon content from a modern standard (F modern). (Source: NOSAMS (https://www2.whoi.edu/site/nosams/))
    Range of values
    Minimum:0.0013
    Maximum:0.0035
    Units:unitless uncertainty on the fraction modern ratio
    Age BP
    The conventional radiocarbon age of the sample in years before present (BP) where "present" by convention is 1950 C.E. If the radiocarbon age was younger than 1950, then the age is listed as ">Modern". (Source: USGS)
    Range of values
    Minimum:105
    Maximum:5490
    Units:years before 1950
    Age BP uncertainty
    The uncertainty in the conventional radiocarbon age of the sample in years. Modern (younger than 1950 C.E.) radiocarbon ages have no uncertainty so in the case of a modern age, this field is blank. (Source: USGS)
    Range of values
    Minimum:15
    Maximum:30
    Units:radiocarbon years
    d13C
    A measure of the fractionation of 12C to 13C, expressed as the ratio of 13C to 12C (delta 13C or d13C). This value is used to correct the fraction modern and the conventional radiocarbon age of the sample, measured by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS). If blank, the d13C of the sample was not measured by NOSAMS. (Source: USGS)
    Range of values
    Minimum:-30.15
    Maximum:-20.10
    Units:unitless ratio
    D14C
    D14C (Delta 14C) is the relative difference between the absolute international standard (base year 1950) and sample activity, corrected for age and d13C (delta 13C). (Source: NOSAMS (https://www2.whoi.edu/site/nosams/))
    Range of values
    Minimum:-499.08
    Maximum:196.18
    Units:unitless

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Khan, Nicole S.
    • Toth, Lauren T.
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Lauren T. Toth
    SOUTHEAST REGION: ST. PETE COASTAL & MARINE SC
    Research Physical Scientist
    600 4Th Street South
    St. Petersburg, FL
    US

    727-502-8029 (voice)
    ltoth@usgs.gov

Why was the data set created?

Data were obtained to reconstruct millennial-scale variability in sea-level change of across the Florida Keys in Khan and others (2022).

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: 2017 (process 1 of 1)
    USGS SPCMSC researchers and academic collaborators collected at total of 91 samples of plant macrofossils or bulk mangrove peat throughout cores SNK-16-C1 and SBC-16-C10, from Snipe Key and Swan Key, respectively, to be used for radiocarbon dating. Macrofossils of mangrove trunks or branches, terminal stems, or prop root bark were collected for dating, where possible. These samples were cleaned of debris using sterile forceps under a binocular microscope before being sent to Woods Hole Oceanographic Institution’s National Ocean Science Accelerator Mass Spectrometry (NOSAMS) laboratory for analysis. At NOSAMS, the macrofossil samples were acid-base-acid pretreated prior to analysis to remove carbonates and other impurities. In parts of the core where there were no macrofossils, researchers instead extracted a 1-centimeter (cm) thick layer of bulk mangrove peat. Those samples were passed through a 63-micron sieve and the <63-micron fractions of the peat samples were transferred onto a clean fiberglass filter and dried at 55 degrees Celsius. Then, the dried bulk peat samples on the filters were shipped to NOSAMS for radiocarbon analysis. The bulk peat samples were acid pretreated by NOSAMS prior to analysis. For additional information on sample preparation, see Khan and others (2022). For additional information about radiocarbon analysis see the NOSAMS website (https://www2.whoi.edu/site/nosams/).
  3. What similar or related data should the user be aware of?
    Khan, Nicole S., Ashe, Erica, Moyer, Ryan P., Kemp, Andrew C., Engelhart, Simon E., Brain, Matthew J., Toth, Lauren T., Chappel, Amanda, Christie, Margaret, Kopp, Robert E., and Horton, Benjamin P., 20220730, Relative sea-level change in South Florida during the past ~5,000 years: Global and Planetary Change Volume 216.

    Online Links:

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

  1. How well have the observations been checked?
    No formal attribute accuracy tests were conducted.
  2. How accurate are the geographic locations?
    No formal positional accuracy tests were conducted.
  3. How accurate are the heights or depths?
    No formal positional accuracy tests were conducted.
  4. Where are the gaps in the data? What is missing?
    Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints None
Use_Constraints None
  1. Who distributes the data set? (Distributor 1 of 1)
    Lauren T. Toth
    SOUTHEAST REGION: ST. PETE COASTAL & MARINE SC
    Research Physical Scientist
    600 4Th Street South
    St. Petersburg, FL
    US

    727-502-8029 (voice)
    ltoth@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Although these data have been processed successfully on a computer system at 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. The USGS shall not be held liable for improper or incorrect use of the data described or contained herein. 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?

Who wrote the metadata?

Dates:
Last modified: 19-Aug-2022
Metadata author:
Lauren T. Toth
SOUTHEAST REGION: ST. PETE COASTAL & MARINE SC
Research Physical Scientist
600 4Th Street South
St. Petersburg, FL
US

727-502-8029 (voice)
ltoth@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/South_Florida_mangrove_peat_radiocarbon_metadata.faq.html>
Generated by mp version 2.9.51 on Fri Aug 19 13:48:13 2022