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Overburden thickness of Fire Clay Coal Zone in Kentucky, Virginia and West Virginia

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

Frequently-anticipated questions:

What does this data set describe?

Title:
Overburden thickness of Fire Clay Coal Zone in Kentucky, Virginia and West Virginia
Abstract:
This map is a generalized representation of the overburden of the Fire Clay coal zone in Virginia, West Virginia, and Kentucky. The coal zone is also known by other names, depending upon locale. It was created by subtracting a grid of coal elevation from a surface topographic grid. Because of the cell sizes of the grid and the highly dissected topography, the 0 to 200-foot overburden category was partly generated by buffering in from the outcrop line 100 meters. The data from West Virginia are not final in nature, as correlation of the beds in this stratigraphic seqence is ongoing. Thus the nature of this product is necessarily provisional. Overburden thickness has been divided into categories based on criteria from USGS Circular 891 (Wood and others, 1983).
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, Overburden thickness of Fire Clay Coal Zone in Kentucky, Virginia 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 (4935)

    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?

    c9125ob.pat
    polygon attribute table for C9125ob coverage (Source: ARC/INFO)

    ob_cat
    A unique code that describes whether coal has been mined or is remaining. A value of 999 is used for internal no-coal areas. (Source: this study)

    ValueDefinition
    1030-200 feet
    105200-500 feet
    106500-1000 feet
    1071000-2000 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, Jr.; VA- R. Sites.

  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 classify resources in this assessment.

How was the data set created?

  1. From what previous works were the data drawn?

    FC-1 (source 1 of 2)
    U.S. Geological Survey, 1998, Digital elevation models.

    Type_of_Source_Media: disc
    Source_Scale_Denominator: 100000
    Source_Contribution:
    USGS DEM's provided the topographic surface used to calculate overburden. Compiler was Philip Freeman.

    FC-2 (source 2 of 2)
    U.S. Geological Survey, 1999, ARC grid c9125st_g - structure on top of the Fire Clay coal.

    Type_of_Source_Media: online
    Source_Scale_Denominator: 100000
    Source_Contribution: This file provided elevation of the Fire Clay coal.

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

    Date: 1998 (process 1 of 13)
    Imported 36 1:100,000 scale (30-minute) DEM's into ARC lattices for central Appalachians (no coverage of Pikeville, Ky and Beckley, WV 100K quadrangles).

    Date: 1998 (process 2 of 13)
    36 lattices merged.

    Date: 1998 (process 3 of 13)
    Imported 32 1:24,000 scale (7.5-minute) DEM's into ARC lattices for both Pikeville, Ky and Beckley, WV 100K quadrangles.

    Date: 1998 (process 4 of 13)
    Lattices of Pikeville, Ky and Beckley, WV 100K quadrangle DEMs were merged, reprojected to geographic, decimal seconds and resampled the cell size to 2 arc-seconds.

    Date: 1998 (process 5 of 13)
    Merged two lattices (30-minute and 7.5-minute).

    Date: 1998 (process 6 of 13)
    Converted Z-units of topographic surface lattice from meters into feet and projected data set into Albers equal area projection to create source FC-1.

    Date: 1999 (process 7 of 13)
    EarthVision grid coverage of Fire Clay structure was exported in ASCII format and imported to ARC (FC-2).

    Date: 1999 (process 8 of 13)
    The structure grid was resampled to the same cell size as the topographic surface grid and was then subtracted from the topographic grid. Contour lines were created using latticecontour in 100-foot intervals. The line values specified in USGS Circular 891 were selected, ungenerated and re-imported to ARC as polygons using an ARC AML from the Illinois State Geological Survey and clipping to the outcrop polygon.

    Date: 1999 (process 9 of 13)
    Manual editing was performed in Arcedit to fix unlabeled polygons and erroneously labeled polygons.

    Date: 1999 (process 10 of 13)
    Outcrop line was buffered 100 meters and attributes added. Unioned buffer coverage and existing overburden coverage. Cleaned cover.

    Date: 1999 (process 11 of 13)
    Rechecked attribute values; updated with internal no-coal areas.

    Date: 2000 (process 12 of 13)
    Dissolved polygons on ob_cat value.

    Date: 2000 (process 13 of 13)
    Projected to geographic.

  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 polygon attributes are classifications of overburden thickness- thickness cutoffs for the classes are accurate to within 50 feet.

  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 data set is a general representation of overburden thickness for the Fire Clay coal zone. 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?

    Topology for this data set was built using the CLEAN command within ARC/INFO, version 7.2.1. This command eliminates dangling nodes, calculates intersections of arcs, eliminates redundant arcs, and creates a polygon attribute table. 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; not accurate at local scales.

  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; c9125ob.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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