Census counts of palynomorphs from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay

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Frequently anticipated questions:

What does this data set describe?

Title:
Census counts of palynomorphs from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay
Abstract:
This data release provides census counts of palynomorphs in sediments of a core obtained off San Francisquito Creek in South San Francisco Bay.
Supplemental_Information:
Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2002-603-DD 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?
    McGann, Mary, and Reidy, Liam M., 20230828, Census counts of palynomorphs from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay: data release DOI: 10.5066/P9QQT6KZ, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    McGann, Mary, Starratt, Scott W., Reidy, Liam M., Lorenson, Thomas D., Phillips, R. Lawrence, and Kneeshaw, Tara A., 2023, Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay: data release DOI:10.5066/P9QQT6KZ, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    Other_Citation_Details:
    Suggested Citation: McGann, M., Starratt, S.W., Reidy, L., Lorenson, T.D., Phillips, R.L., and Kneeshaw, T.A., 2023, Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay: U.S. Geological Survey data release, https://doi.org/10.5066/P9QQT6KZ.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.0961
    East_Bounding_Coordinate: -122.0961
    North_Bounding_Coordinate: 37.4583
    South_Bounding_Coordinate: 37.4583
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2002
    Ending_Date: 2023
    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 (24)
    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 North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.978698214.
  7. How does the data set describe geographic features?
    A comma-separated values file with the first line being a header line.
    Census counts of palynomorphs in fine sediment. (Source: Producer defined.)
    Date_Collected
    Date in year. (Source: Producer defined.)
    Range of values
    Minimum:2002
    Maximum:2002
    Latitude
    Latitude of the site at which the push core was collected. (Source: Producer defined.)
    Range of values
    Minimum:37.4583
    Maximum:37.4583
    Units:decimal degrees
    Resolution:0.0001
    Longitude
    Longitude of the site at which the push core was collected. (Source: Producer defined.)
    Range of values
    Minimum:-122.0961
    Maximum:-122.0961
    Units:decimal degrees
    Resolution:0.0001
    Sample_Upper_Depth_Limit_cm
    The upper depth at which the sediment sample was obtained below the sediment surface in a core. (Source: Producer defined.)
    Range of values
    Minimum:0
    Maximum:160
    Units:centimeters
    Resolution:1
    Sample_Lower_Depth_Limit_cm
    The lower depth at which the sediment sample was obtained below the sediment surface in a core. (Source: Producer defined.)
    Range of values
    Minimum:1
    Maximum:161
    Units:centimeters
    Resolution:1
    Percent_abundance_palynomorph_taxa.
    Columns 6 to 23 are percent abundances of each palynomorph taxon in the total palynomorph assemblage and the sum of these columns is approximately 100 percent. The list of palynomorph taxa below includes both the abbreviation and the full taxonomic binomial nomenclature and is presented in the same order as the taxa on the data file. (Source: Producer defined)
    ValueDefinition
    List of palynomorph taxa Pinus represents Pinus Quercus represents Quercus Sequoia represents Sequoia Alnus represents Alnus Lithocarpus represents Lithocarpus Acer represents Acer Eucalyptus represents Eucalyptus Juglans represents Juglans Chenopodiaceae represents Chenopodiaceae Cyperaceae represents Cyperaceae Typha_latifolia represents Typha latifolia Linnaeus Poaceae represents Poaceae RRA represents Rhamnceae, Roseceae, and Ancardiaceae Trilete_Spore represents Trilete Spore Monolete_Spore represents Monolete Spore Erodium_cicutarium represents Erodium cicutarium (Linnaeus, 1753) L'Hertier ex. Aiton, 1789 Plantago_lanceolata represents Plantago lanceolata Linnaeus Cruciferae represents Cruciferaepercent abundance ranging from 0-100
    Entity_and_Attribute_Overview:
    The first line of the comma-separated values 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)
    • Mary McGann
    • Liam M. Reidy
  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

    650-329-4979 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

The urbanized area of downtown Menlo Park is subject to persistent flooding and sediment deposition by San Francisquito Creek in South San Francisco Bay. To mitigate these events, a suite of cores was collected in 2002 at the mouth of the creek to determine sediment depositional rates on the delta. One of those cores was selected for microbiological (pollen, diatoms, and foraminifera) and geochemical analyses to reconstruct a depositional record over the past two millennia. Based on an abrupt change in lithology and faunal assemblages, an instantaneous vertical displacement and deepening of the depositional environment is evident. Coseismic subsidence associated with large fault ruptures may cause these events. An age model based on the first appearances of non-indigenous biota, radiocarbon dates, radiochemistry, and sediment geochemistry suggests the 1868 rupture of the Hayward Fault may have been the cause.

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: 2002 (process 1 of 2)
    A metal core barrel, approximately 9 cm in diameter, was driven into the mudflat slightly northwest of Hooks Point on informally named "Hooks Island" in South San Francisco Bay near Palo Alto, California in 2002 to recover a sediment core. The precise coring location is not available. The core was brought to the the USGS facility in Menlo Park, California and housed in a core refrigerator.
    Date: 2003 (process 2 of 2)
    Twenty-four samples of approximately 1 cubic cm were obtained from core 721-1 for palynomorph analysis every 10 cm downcore starting with the surface of the core down to 160 cm, as well as every 5 cm from 140-80 cm. One tablet containing approximately 13,679 Lycopodium spores was added to each sample for control purposes and to calculate pollen concentration. Samples were sieved with a 125-?m-mesh filter to remove large debris and then processed with the following treatments: 10 percent hydrochloric acid, 10 percent potassium hydroxide, 52 percent hydrofluoric acid, isopropynol wash, 70 percent nitric acid, and an acetolysis solution of nine parts glacial acetic acid to one part concentrated sulfuric acid. The residues were stained with safranin, dehydrated with tertiary butyl alcohol, suspended in silicone oil, and mounted on microscope slides. Palynomorphs were identified and counted on a Zeiss light microscope at 400X magnification. Grains that were characterized yet could not be identified were labeled as "Unknown". Damaged, torn or crumpled grains that were unidentifiable were counted as "Indeterminate". An average of 400 pollen grains and fern spores were counted for 24 samples. Lycopodium spores were counted in order to calculate pollen concentration. Pollen types and fern spores were identified to the lowest taxonomic level possible. Terrestrial pollen percentages were calculated from the sum of terrestrial pollen and fern spores. The pollen slides and residues of this study are on file at the UC Berkeley Geography Department Quaternary Paleoecology Laboratory.
  3. What similar or related data should the user be aware of?

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

  1. How well have the observations been checked?
    Microscopes are operationally checked every year to assure optics are aligned and visual acuity can be maximized during sorting and identifications. Specimen identifications were compared to reference material (actual specimens and published monographs) to ensure idenfications were accurate. Specimen enumeration (counts) were checked with original laboratory bench sorting sheets to assure numbers were correct, and the sorting and data entry into spreadsheets was rechecked at least once.
  2. How accurate are the geographic locations?
    A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. The horizontal position was estimated based on distances from the modern tidal channel listed on a figure provided to the first author in October 2003. The horizontal accuracy cannot be determined.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the metadata for each part of this data release carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    Data were checked for logical consistency by the laboratory staff before release to confirm that numerical values were not outside a reasonable range for a particular field. Cumulative counts of percentage data for total palynomorphs had to equal approximately 100% to ensure numbers were reported correctly.

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 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 - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in a comma-delimited text file (SFC_palynomorphs_data.csv) which contains results from census counts of palynomorphs from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay.
  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?
  5. What hardware or software do I need in order to use the data set?
    These data can be viewed with any text editor software.

Who wrote the metadata?

Dates:
Last modified: 28-Aug-2023
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/ScienceBase/DR_P9QQT6KZ/SFC_palynomorphs_metadata.faq.html>
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