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Contours of potentially minable thickness for the Fire Clay coal zone in Virginia, Kentucky, and West Virginia

Metadata also available as - [Outline] - [Parseable text] - [DIF]

Frequently-anticipated questions:

What does this data set describe?

Title:
Contours of potentially minable thickness for the Fire Clay coal zone in Virginia, Kentucky, and West Virginia
Abstract:
This dataset represents the thickness of the potentially minable Fire Clay coal benches in Virginia, West Virginia, and Kentucky. The coal zone is known by other names, depending upon locale. The data were comprised of values from Kentucky in EXCEL format, data searched from the USGS' NCRDS database for Virginia and entered into StratiFact, and a StratiFact database obtained from the West Virginia Geological and Economic Survey (WVGES). Point data were gridded, the grid contoured and imported to ARC/INFO as polygons. The Kentucky portion was replaced by a polygonal thickness coverage obtained from the Kentucky Geological Survey that had been manually contoured, therefore State line discrepancies are to be expected. The data obtained from the WVGES are not final in nature, because correlation of the beds in this stratigraphic sequence is ongoing. Thus the nature of this product is necessarily provisional.
This map is one of many Geographic Information System (GIS) products of the National Coal Assessment that is being conducted by the U.S. Geological Survey in cooperation with State geological surveys and other Federal and State agencies. The Middle Pennsylvanian Pottsville Group Fire Clay coal is an important resource in the Central Appalachian Basin coal region and has been mined for the last one hundred years. The Fire Clay coal is most commonly referred to as the Fire Clay (Hazard No. 4) in Kentucky, the Phillips in Virginia, and the Fire Clay in West Virginia. This resource model for the Fire Clay coal zone must be considered provisional, because the correlation of the zone continues to be evaluated in West Virginia.
  1. How should this data set be cited?

    Tewalt, Susan J. , 2000, Contours of potentially minable thickness for the Fire Clay coal zone in Virginia, Kentucky, and West Virginia:.

    This is part of the following larger work.

    Northern and Central Appalachian Basin Coal Regions Assessment Team, 2000, 2000 Resource Assessment of Selected Coal Beds and Zones in the Northern and Central Appalachian Basin Coal Regions: U.S. Geological Survey Professional Paper PP1625-C, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -84.114
    East_Bounding_Coordinate: -81.533
    North_Bounding_Coordinate: 38.099
    South_Bounding_Coordinate: 36.599

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 2000
    Currentness_Reference: data collection and collation period

  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):

      • GT-polygon composed of chains (3268)

    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 1/294.98.

  7. How does the data set describe geographic features?

    c9125is.pat
    polygon attribute table for C9125is coverage (Source: ARC/INFO)

    thick
    Potentially minable coal thickness; 0 values in internal no-coal areas (Source: this study)

    Range of values
    Minimum:0
    Maximum:8.755
    Units:feet

    is_cat
    USGS Circular 891 thickness category code (Source: this study)

    ValueDefinition
    0internal no-coal area
    100less than 1.17 feet (14 inches)
    1011.17 feet to 2.34 feet
    1022.34 feet to 3.5 feet
    1033.5 feet to 7.0 feet
    104greater than 7.0 feet

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    State geological surveys maintain the most recent coal maps and have provided the USGS with the data necessary to complete the assessment. Primary contacts at the State surveys for this product include: KY- G. Weisenfluh, WV- B.M. Blake, VA- R. Sites. It is recommended that new data be obtained from the State geological surveys that are the sources of the information used in this study. Information for Kentucky can be found online at: <http://www.uky.edu/KGS/home.htm>.

  3. To whom should users address questions about the data?

    Susan J. Tewalt (compiler)
    U.S. Geological Survey, Eastern Energy Resources Team
    MS 956 National Center
    Reston, Virginia 20192
    USA

    703-648-6437 (voice)

Why was the data set created?

The purpose of Professional Paper 1625 is to release the interpretation of assessment and modeling data for the the top-producing coal beds in the northern and central Appalachian Basin coal region. The purpose of this cover was to provide coal thickness for determining resources in this study.

How was the data set created?

  1. From what previous works were the data drawn?

    VA-1 (source 1 of 3)
    Virginia Division of Mineral Resources, 1998, StratiFact database generated from National Coal Resources Data System database.

    Type_of_Source_Media: online
    Source_Scale_Denominator: 24000
    Source_Contribution:
    Data searched from NCRDS for Virginia were the entire basis for thickness of potentially minable benches of the Fire Clay coal zone in Virginia.

    KY-1 (source 2 of 3)
    Survey, Kentucky Geological , 1997, fcl_thk.e00; export Arc/Info cover of thickness for Fire Clay.

    Type_of_Source_Media: online
    Source_Scale_Denominator: 100,000
    Source_Contribution:
    This file was total source for thickness contours (digitized from manually drawn contours) for the Fire Clay coal zone in Kentucky.

    WV-1 (source 3 of 3)
    West Virginia Geological and Economic Survey, 1998, WVGES StratiFact database for Fire Clay coal..

    Type_of_Source_Media: online
    Source_Scale_Denominator: 24000
    Source_Contribution:
    Data searched were complete basis for thickness in West Virginia.

  2. How were the data generated, processed, and modified?

    Date: 1998 (process 1 of 10)
    1. All appropriate thickness data from KCRIS databases were plotted on 1:100,000-scale base maps and overlain with facies lines representing coal bed discontinuities. Coal thickness isolines were hand drawn for standard U.S.G.S. thickness categories (Wood and others, 1983). Contours were drawn so that they did not cross facies boundaries, as these are considered discontinuities of the bed. Isolated values that were inconsistent with surrounding data were ignored in order to avoid overly complex maps. Vector polygons were digitized in ARC/INFO and encoded with category labels to create data spurce KY-1. Contributions by : G. Weisenfluh and E. Thacker.

    Date: 1998 (process 2 of 10)
    NCRDS data downloaded for Virginia. Fire Clay (Phillips coal in Virginia) data were checked against original records for the Appalachia 7.5' quad (which had been verified and correlated by VDMR). Correlations for the Fire Clay were verified or created by USGS for holes in the remainder of the Virginia dataset.

    Date: 1999 (process 3 of 10)
    Fire Clay thicknesses were searched from the VA database and merged with data searched from the WV StratiFact database. Searches were done by name and lithology, which had been established using criteria for determining which bench(es) of the Fire Clay could be potentially mined. The values were appended to public KY thickness values which had been provided to the USGS in spreadsheet format. Data were input to EarthVision and projected to Albers coordinates from geographic.

    Date: 1999 (process 4 of 10)
    Data were gridded using 300 meter cell size, isopach algorithm, extrapolation, exact z range, 4 neighboring point search, and no faults. Grid was multiplied by 100 and contoured using specified contour intervals (representing 1.17 ft) and exported into an ASCII file.

    Date: 1999 (process 5 of 10)
    ASCII contour lines imported to ARC/INFO as polygons using ARC AML from Illinois State Geological Survey, clipping with a simple polygon. Manual corrections made for missing polygon labels; polygons less than 90,000 square meters were selected and deleted.

    Date: 1999 (process 6 of 10)
    The KY part of the thickness coverage was removed by using a coverage from the Kentucky Geological Survey as an erase cover. The items in both covers were then altered to be the same and mapjoined.

    Date: 1999 (process 7 of 10)
    The polygons were clipped by a polygon coverage representing the outcrop/resource assessment areas of the Fire Clay coal.

    Date: 1999 (process 8 of 10)
    The coverage was updated with internal no-coal polygons.

    Date: 1999 (process 9 of 10)
    An attribute was added to group thicknesses into the resource categories specified in USGS Circular 891.

    Date: 1999 (process 10 of 10)
    Projected to geographic coordinates.

  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?

    Deductive_Estimate: The range of the input data was from 0 to 8.58 feet, with a mean of 2.00 ft and a standard deviation of 1.44 ft. The grid from which these contours were obtained had a mean of 1.6 ft and a standard deviation of 1.5, with an average z error of 0.1 ft. In areas of sparse data, the coverage will not reflect ground truth. This thickness coverage does not represent the entire Fire Clay coal zone thickness, but the thickness of the benches that are most likely to be mined.

  2. How accurate are the geographic locations?

    Locations of the input points used to create this cover are estimated to be accurately located within 1/4 mile.

  3. How accurate are the heights or depths?

    Fire Clay thicknesses were searched from the VA database and merged with data searched from the WV StratiFact database. Searches were done by name and lithology, which had been established using criteria for determining which bench(es) of the Fire Clay could be potentially mined. The values were appended to public KY thickness values which had been provided to the USGS in spreadsheet format. [Different stratigraphic nomenclature is a problem in merging state StratiFact databases into one.] Data were input to EarthVision and projected to Albers coordinates from geographic.

  4. Where are the gaps in the data? What is missing?

    The input data to this coverage will be more complete in the future and possibly revised in the State of West Virginia. The source maps are believed to be the most up to date at the time of collection. State agencies reviewed the data set for completeness. The State of Tennessee is not included in this coverage.

  5. How consistent are the relationships among the observations, including topology?

    This data set does not contain dangles or redundant arcs.

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: To be used for regional analysis only.

  1. Who distributes the data set? (Distributor 1 of 1)

    Susan J. Tewalt
    U.S. Geological Survey, Eastern Energy Resources Team
    MS 956 National Center
    Reston, Virginia 20192
    USA

    703-648-6437 (voice)

  2. What's the catalog number I need to order this data set?

    USGS Professional Paper 1625-C: Chapter F; c9125is.e00

  3. What legal disclaimers am I supposed to read?

    Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 04-Apr-2000
Metadata author:
Susan J. Tewalt (compiler)
U.S.Geological Survey, Eastern Energy Resources Team
MS 956 National Center
Reston, Virginia 20192
USA

703-648-6437 (voice)

Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

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