Metadata: Identification_Information: Citation: Citation_Information: Originator: USGS; Eastern Energy Resource Team; Susan J. Tewalt Publication_Date: 1999 Title: Thickness contours of the Pittsburgh coal bed in Pennsylvania, Ohio, West Virginia, and Maryland (in USGS Circular 891 thickness categories) Description: Abstract: This dataset is a polygon coverage of the thickness of the Pittsburgh coal bed main bench, in feet, over the extent of the Pittsburgh coal bed resource areas designated for this study. The coverage was produced by gridding (producing 300 meter cells) 4,556 point-source data from the National Coal Resources Data System (NCRDS) of the USGS, using ISM (Version 7.1) software, subsequently contoured into 1.17-ft (14-inch) intervals, and imported to ARC/INFO. The 'thick' item for each polygon reflects a value in feet halfway between the bounding contour lines. The 'thick_is_cat' item is a category code from criteria in USGS Circular 891. Coverage name: c9024is (024 is the code assigned to the Pittsburgh Coal bed). Zero thickness areas were not differentiated as to whether they were depositional or erosional, a deviation from standard USGS Circular 891 methodology. The coverage's polygons have been clipped to the resource areas designated on USGS Open-File Report 96-280, scale 1:425,000. Thickness contour lines are also available extrapolated over the entire extent of the Pittsburgh coal bed and its horizon (also see Open-File Report 97-748 for a generalized version of these isopach contours). 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 is useful for regional studies- not necessarily applicable to local scales. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1970's Ending_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 thickness Theme_Keyword: bituminous Theme_Keyword: isopach 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 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 NCRDS has been submitted by State Geological Surveys and USGS scientists since its inception in 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: The range of thickness values in the point-source information was 0 to 12.84 feet. The resultant range of the gridded surface was negative to 27 feet; extrapolation was used over the x,y extent. The average absolute Z-error of the grid was 0.14 feet, which is 0.4 percent of the range. Logical_Consistency_Report: Topologically clean Completeness_Report: Input points were irregularly distributed over the spatial extent of the study, therefore areas of sparse data will not reflect ground truth. The main bench of the Pittsburgh coal was selected by name from the stratigraphic data base stored in StratiFact, a relational data base manager in use by the USGS National Coal Assessment. The original data submitted to NCRDS may not have had the main bench identified, a task performed within StratiFact by examining data in cross sections. Data used were selected by geologist from the database. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: A wide variety of data sources were used as input to this data set. The worst horizontal error is expected to be approximately 1/4 mile. Original data were stored in NCRDS in latitude/longitude coordinates with a possible precision of decimal seconds. Some loss of precision was made upon conversion to StratiFact. Location coordinates were converted to Albers Equal Area projection (.01 meter precision) prior to gridding in ISM. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The raw input data represent thickness measurements from a wide variety of data types: cores, outcrop, oil and gas logs, etc. The original errors associated with these measurments are unknown. Error may also arise from the differences in the judgement of geologists in the differentiation between coal, bone and partings. Only coal and impure coal lithologies were included in the database search to determine cumulative coal thickness; bone coal and partings were excluded. Lineage: Process_Step: Process_Description: Pittsburgh Coal data from NCRDS printed and verified against original data sources. Process_Date: 1995 Process_Step: Process_Description: Corrections made to West Virginia and Maryland data in StratiFact. Corrections made to Pennsylvania data in NCRDS (Ingres). Pennsylvania data downloaded to StratiFact. StratiFact data base obtained from OHGS for Ohio. Process_Date: 1995-1996 Process_Step: Process_Description: Editing of individual data bases in StratiFact to eliminate data coding differences between states. Process_Date: 1997 Process_Step: Process_Description: Gridding of thicknesses and further addition and refinement of data values in StratiFact data bases. ISM (v.7.1) grid parameters used: isopach surface algorithm (special treatment of zero values), 300 meter cell size, extrapolation of values over specified x,y extent plus 5%. Average absolute Z-error of the grid was 0.14 feet, or 0.4% of the range. Process_Date: 1997 Process_Step: Process_Description: Grid was contoured in ISM into 1.17-foot intervals, using 0 to 14 feet as limits. The 1.17 feet is approximately the 14-inch interval used in USGS Circular 891. Process_Date: 1997 Process_Step: Process_Description: Import of contours to ARC/INFO for the entire basin, using conversion ARC/INFO AML provided by Illinois State Geological Survey, and rectangular area ARC coverage (box) to enclose polygons. Process_Date: 1997-1998 Process_Step: Process_Description: Changed name of item for thickness to thick. Added item for thickness category (thick_is_cat) and populated it by graphically selecting desired polygons by thickness in ARCEDIT and calculating the category value. Process_Date: 1998 Process_Step: Process_Description: Clipped ARC coverage to resource areas (c9024ro) using net option. Process_Date: 1998 Process_Step: Process_Description: Projected coverage to geographic coordinates. Process_Date: 1998 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: c9024is.pat Entity_Type_Definition: polygon attribute table for coverage Entity_Type_Definition_Source: ARC/INFO Attribute: Attribute_Label: thick Attribute_Definition: average thickness value of bounding contour lines Attribute_Definition_Source: ARC/INFO Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1.755 Range_Domain_Maximum: 13.455 Attribute_units_of_measure: feet Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.17 Attribute_Value_Accuracy_Explanation: plus or minus one contour interval, in feet Attribute: Attribute_Label: thick_is_cat Attribute_Definition: category label for coal bed thickness Attribute_Definition_Source: ARC/INFO Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 101, 102, 103, 104, 999 Enumerated_Domain_Value_Definition: '101' is 1.17 - 2.34 feet '102' is 2.34 - 3.51 feet '103' is 3.51 - 7.02 feet '104' is 7.02 - 14 feet '999' is < 1.17 feet and not used in resource calculations Enumerated_Domain_Value_Definition_Source: USGS Entity_Type: Entity_Type_Label: c9024is.aat Entity_Type_Definition: arc attribute table for coverage Entity_Type_Definition_Source: ARC/INFO Attribute: Attribute_Label: thickness Attribute_Definition: thickness contour value Attribute_Definition_Source: ARC/INFO Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 1.17, 2.34, 3.50, 4.67, 5.84, 7.02, 8.19, 9.36, 10.53, 11.70, 12.87, 14.04, -999 Enumerated_Domain_Value_Definition: 1.17 foot contour line 2.34 foot contour line 3.50 foot contour line 4.67 foot contour line 5.84 foot contour line 7.02 foot contour line 8.19 foot contour line 9.36 foot contour line 10.53 foot contour line 11.70 foot contour line 12.87 foot contour line 14.04 foot contour line -999 clipping polygon arc Enumerated_Domain_Value_Definition_Source: USGS 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: