Metadata: Identification_Information: Citation: Citation_Information: Originator: USGS; Eastern Energy Resource Team; Susan J. Tewalt Publication_Date: 1997 Title: Map showing structure contours and overburden thickness isopleths of the Pittsburgh Coal Bed in Pennsylvania, Ohio, West Virginia, and Maryland Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 97-864, two sheets, 1:425,000 Publication_Information: Publication_Place: Reston, VA Publisher: USGS; Eastern Energy Resources Description: Abstract: This dataset is a polygon coverage of the thickness of the overburden of the Pittsburgh Coal bed main bench, in feet. It was produced by importing 1:250,000 and 1:100,000 scale digital elevation models into ARC, and merging the lattices into one. The ARC grid was imported to GRASS where it was resampled to the 300 meter cells that were used in the generation of the structure contour map on top of the Pittsburgh coal bed main bench. The structure elevation grid was subtracted from the surface elevation grid, creating overburden thickness. This grid was contoured within the known extent of the Pittbsurgh coal bed and horizon into 200, 500, 1000, and 2000 foot lines. This vector file was imported to ARC. Overburden polygons less than 90,000 square meters in area were deleted (represented one grid cell or less and were too detailed for this regional scale product). In addition some areas of steep terrain required editing of the 200 foot contour line to be inside the Pittsburgh outcrop line (which represents 0 ft overburden). Overlap occurred because the contour lines were generated from 300-m cells. Coverage name is c9024ob. Polygon attributes include a code for the USGS overburden category (and arc attributes include the value of the contour line). Purpose: This dataset was used in the National Coal Resource Assessment Program in the regional evaluation of resources for the Pittsburgh coal bed in Region 9, the Appalachians. The dataset has been generalized and is useful in regional studies - not applicable to local scales. Time_Period_of_Content: Time_Period_Information: Single_date/Time: Calendar_Date: 1997 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -82.657 East_Bounding_Coordinate: -78.604 North_Bounding_Coordinate: 40.635 South_Bounding_Coordinate: 38.315 Keywords: Theme: Theme_Keyword_Thesaurus: Coal Resource Classification of the U.S. Geological Survey, USGS Circular 891. Theme_Keyword: coal Theme_Keyword: coal resources Theme_Keyword: coal overburden Theme_Keyword: bituminous Theme_Keyword: geologic structure Theme_Keyword: outcrop Theme_Keyword: USGS Theme_Keyword: West Virginia Geological and Economic Survey Theme_Keyword: Ohio Division of Geological Survey Theme_Keyword: Maryland Geological Survey Theme_Keyword: Pennsylvania Bureau of Topographic and Geologic Survey Place: Place_Keyword_Thesaurus: Geographic Names Information System Place_Keyword: Appalachians Place_Keyword: CLAY County WV Place_Keyword: RITCHIE County WV Place_Keyword: MUSKINGUM County OH Place_Keyword: MONROE County OH Place_Keyword: WETZEL County WV Place_Keyword: TYLER County WV Place_Keyword: MARION County WV Place_Keyword: MONONGALIA County WV Place_Keyword: GREENE County PA Place_Keyword: BROOKE County WV Place_Keyword: TAYLOR County WV Place_Keyword: KANAWHA County WV Place_Keyword: LINCOLN County WV Place_Keyword: WAYNE County WV Place_Keyword: TUCKER County WV Place_Keyword: GRANT County WV Place_Keyword: MINERAL County WV Place_Keyword: GARRETT County MD Place_Keyword: SOMERSET County PA Place_Keyword: CAMBRIA County PA Place_Keyword: PRESTON County WV Place_Keyword: FAYETTE County PA Place_Keyword: BARBOUR County WV Place_Keyword: UPSHUR County WV Place_Keyword: BRAXTON County WV Place_Keyword: CABELL County WV Place_Keyword: LAWRENCE County OH Place_Keyword: GALLIA County OH Place_Keyword: MASON County WV Place_Keyword: PUTNAM County WV Place_Keyword: JACKSON County WV Place_Keyword: MEIGS County OH Place_Keyword: ROANE County WV Place_Keyword: WIRT County WV Place_Keyword: CALHOUN County WV Place_Keyword: ATHENS County OH Place_Keyword: WASHINGTON County OH Place_Keyword: WOOD County WV Place_Keyword: PLEASANTS County WV Place_Keyword: GILMER County WV Place_Keyword: DODDRIDGE County WV Place_Keyword: MORGAN County OH Place_Keyword: HARRISON County WV Place_Keyword: NOBLE County OH Place_Keyword: GUERNSEY County OH Place_Keyword: BELMONT County OH Place_Keyword: OHIO County WV Place_Keyword: HARRISON County OH Place_Keyword: CARROLL County OH Place_Keyword: JEFFERSON County OH Place_Keyword: MARSHALL County WV Place_Keyword: BEAVER County PA Place_Keyword: ALLEGHENY County PA Place_Keyword: ARMSTRONG County PA Place_Keyword: INDIANA County PA Place_Keyword: WESTMORELAND County PA Place_Keyword: ALLEGANY County MD Place_Keyword: LEWIS County WV Place_Keyword: HANCOCK County WV Place_Keyword: WASHINGTON County PA Stratum: Stratum_Keyword_Thesaurus: Geologic Names Unit Lexicon (GNULEX), 1996; Stratigraphic Nomenclature Databases for the United States, It's possessions, and Territories, U.S. Geological Survey Digital Data Series DDS-6, release 3. Stratum_Keyword: Pittsburgh coal bed horizon Stratum_Keyword: Pittsburgh coal Stratum_Keyword: Upper Pennsylvanian Stratum_Keyword: Monongahela Group Stratum_Keyword: Conemaugh Group Access_Constraints: none Use_Constraints: none Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Susan J. Tewalt Contact_Address: Address_Type: mailing address Address: MS 956 National Center City: Reston State_or_Province: Virginia Postal_Code: 20192 Country: USA Contact_Voice_Telephone: 703-648-6437 Data_Set_Credit: The stratigraphic data stored in the National Coal Resources Data System (NCRDS) was submitted from the middle 1970's through state cooperative programs. The data for the Pittsburgh coal bed was used with the permission and through the cooperation of coal geologists (primary contacts listed) at the West Virginia Geological and Economic Survey (Nick Fedorko), the Pennsylvania Bureau of Topographic and Geologic Survey (James R. Shaulis and Viktoras W. Skema), the Ohio Division of Geological Survey (Richard W. Carlton) and the Maryland Geological Survey (Dave Brezinski). [WVGES, PAGS, OHGS, and MDGS, respectively.] Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Deductive Estimate: Because many small-scale features were removed (individual hills and upper reaches of erosional features),local accuracy is estimated to be poor. Polygons with an area of less than 90,000 square meters were selected and merged into the overburden value of the surrounding polygon. The original uncleaned line file (prior to any ARC editing) for the entire basin is available upon request. Logical_Consistency_Report: Topologically clean Completeness_Report: The polygons in this coverage are a general representation of overburden thickness based on categories prescribed by USGS Circular 891. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The grid cell sizes used to create this file were 300 meter square. The contouring routine may go to either side of a cell, therfore horizontal accuracy is estimated to minimally be 150 meters. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The polygonal data values represent the subtraction of the top of the Pittsburgh Coal main bench from a DEM lattice. The original measurement errors associated with the DEM vary with scale; errors associated with the structure contour map are likely to be on the order of 50 feet. These errors are likely to be cumulative. The grid which produced the contours for this coverage's polygons had a maximum value for overburden thickness of approximately 1450 feet within the resource areas shown on this coverage. Lineage: Process_Step: Process_Description: Gridding of Pittsburgh coal elevations to create structure on the top of the main bench, using ISM v. 71. Grid parameters used: normal minimum tension surface algorithm, 300 meter grid size, extrapolation over specified x,y extent. Creation of contours with 50-foot interval. Process_Date: 1997 Process_Step: Process_Description: Imported 10 1:250,000 scale DEM's into ARC lattices. Process_Date: 1997 Process_Step: Process_Description: 10 lattices merged and cell size resampled to 100 meters. Process_Date: 1997 Process_Step: Process_Description: Imported 8 1:100,000 scale DEM's into ARC lattices. Process_Date: 1997 Process_Step: Process_Description: 8 lattices merged and cell size resampled to 100 meters. Process_Date: 1997 Process_Step: Process_Description: Merged two lattices (1:250,000 and 1:100,000). Process_Date: 1997 Process_Step: Process_Description: Converted Z-units of topographic surface lattice from meters into feet and projected data set into Albers equal area projection. Process_Date: 1997 Process_Step: Process_Description: Imported final ARC topographic surface grid (as ASCII file) and imported ISM structure grid (as ASCII file) to GRASS. Process_Date: 1997 Process_Step: Process_Description: Resampled topography grid to same cell size (300 m) as structure. Calculated overburden by subtraction of structure from topography. Contoured overburden grid into line file (limited to within the extent of the Pittsburgh coal bed and horizon) using specific thickness values: 200, 500, 1000, and 2000 feet (2000 line exceeded maximum of actual values). This step used GRASS's r.resample, r.mapcalc, r.contour, and lastly v.out.arc commands. Process_Date: 1997 Process_Step: Process_Description: Imported overburden contour lines to ARC (over coal bed horizon extent) as vector using generate command. Process_Date: 1997 Process_Step: Process_Description: Cleaned for line with dangle and fuzzy set to 1, edited out dangles and built polygon topology. Deleted polygons of AREA less than 90,000 square meters; used selectput to delete arcs of that same subset. Dissolved 500 common lines. Process_Date: 1997 Process_Step: Process_Description: Manually edited small changes to 200 foot contour line using known resource areas (cover, C9024ro) as backcoverage guide so that the 200-foot contour line occurred within the outcrop area. Process_Date: 1997 Process_Step: Process_Description: Cleaned and used matchnode to close nodes, manual editing in ARCEDIT as final step. Process_Date: 1997 Process_Step: Process_Description: Clipped contours to the known resource areas defined in USGS Open-File Report 96-280 (ARC/INFO coverage C9024ro). The clipping coverage also provided the zero overburden thickness line (outcrop). Process_Date: 1997 Process_Step: Process_Description: Ran createlabels, added item for catgeory code, and manually attributed polygons with numeric codes for their respective overburden category. Process_Date: 1997 Process_Step: Process_Description: Manually added two additional polygons of deeper overburden categories to Ohio (Gallia county) based on maps sent by OHGS. Process_Date: 1998 Process_Step: Process_Description: Projected cover to geographic from albers. Process_Date: 1998 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.00001 Longitude_Resolution: 0.00001 Geographic_Coordinate_Units: decimal degrees Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: c9024ob.pat Entity_Type_Definition: polygon attribute table for coverage Entity_Type_Definition_Source: ARC/INFO Attribute: Attribute_Label: THICK_OB_CAT Attribute_Definition: numeric code assigned to categories defined in USGS Circular 891. Attribute_Definition_Source: ARC/INFO Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 101, 102, 103, 104, 105, 106, 107, 108, 109, 110 Enumerated_Domain_Value_Definition: '101' 0 to 500 feet '102' 0 to 100 feet '103' 0 to 200 feet *in this coverage '104' 100 to 200 feet '105' 200 to 500 feet *in this coverage '106' 500 to 1000 feet *in this coverage '107' 1000 to 2000 feet *in this coverage '108' 2000 to 3000 feet '109' 300 to 6000 feet '110' 6000+ feet '999' "no coal" area for which overburden does not exist *in this coverage Enumerated_Domain_Value_Definition_Source: USGS Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 50 Attribute_Value_Accuracy_Explanation: Elevation on top of the Pittsburgh coal bed main bench (exclusive of roof coals) in feet was created by subtraction of depth down drill hole from surface elvation, gridded, and averaged to nearest 50 feet by means of contouring. Subtraction of this surface from topography was then contoured into varying intervals, 200, 500, 1000, and 2000. Because of the generalization of this coverage, 50 feet would be the minimum accuracy, a greater value is likely. Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Susan J. Tewalt Contact_Address: Address_Type: mailing address Address: MS 956 National Center City: Reston State_or_Province: Virginia Postal_Code: 20192 Country: USA Contact_Voice_Telephone: 703-648-6437 Resource_Description: Pittsburgh Coal dataset Distribution_Liability: This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARCE Format_Version_Number: 7.1.1 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: