Identification_Information: Citation: Citation_Information: Originator: United States Geological Survey (USGS) Central Region Energy Resources Team Publication_Date: 19990930 Title: gilovb.shp (Overburden above the Wyodak-Anderson coal zone in the Gillette coalfield) Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: U. S. Geological Survey Professional Paper Issue_Identification: 1625-A Publication_Information: Publication_Place: Denver, CO Publisher: USGS Central Region Energy Resources Team Description: Abstract: This ArcView shapefile contains a polygon representation of overburden thickness above the Wyodak-Anderson coal zone in the area of Gillette coalfield, Wyoming. This theme was created specifically for the National Coal Resource Assessment in the Northern Rocky Mountains and Great Plains Region Purpose: The Nation's coal resources are being assessed by the USGS. This assessment identifies and characterizes the coal beds and coal zones that will provide the bulk of the Nation's coal-derived energy during the next few decades. This assessment is different from previous USGS assessments because digital files and databases are being collected and stored in standardized formats, and being analyzed using a Geographic Information System (GIS). Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19981023 Currentness_Reference: Publication Date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -105.6950 East_Bounding_Coordinate: -105.1358 North_Bounding_Coordinate: 44.5251 South_Bounding_Coordinate: 43.3885 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Overburden Theme_Keyword: Wyodak-Anderson coal zone Theme_Keyword: Isopach Theme_Keyword: Northern Rocky Mountains and Great Plains Fort Union Coal Resources Assessment Theme_Keyword: USGS National Coal Resource Assessment Theme_Keyword: Overburden isopach map Theme_Keyword: Minimum overburden Place: Place_Keyword_Thesaurus: None Place_Keyword: Powder River Basin Place_Keyword: Gillette coalfield Place_Keyword: Wyoming Place_Keyword: Gillette Place_Keyword: Campbell County Place_Keyword: Converse County Place_Keyword: Northern Rocky Mountains and Great Plains Region Access_Constraints: None Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Energy Resources Team Contact_Person: Margaret Ellis Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303.236.7775 Contact_Electronic_Mail_Address: mellis@usgs.gov Hours_of_Service: Monday through Friday 8:00 AM- 3:00 PM Native_Data_Set_Environment: ArcView version 3.0 ARC/INFO 7.1.2 SUNOS, 5.6 SUN4U UNIX Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No test was performed to assess attribute accuracy. Logical_Consistency_Report: Polygon features present Completeness_Report: Wyodak-Anderson overburden is limited to the area of the Gillette Coalfield Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Limited to software coordinates precision for geographic coordinates. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: USGS Energy Resources Team(comp.) Publication_Date: Unpublished material Publication_Time: Unknown Title: USGS National Coal Resources Data System Geospatial_Data_Presentation_Form: map Other_Citation_Details: US Geological Survey Energy Resources Team MS 956 Reston, VA 20192 (attn. M.D. Carter) Source_Scale_Denominator: 250000 Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19880805 Source_Currentness_Reference: Publication Date Source_Citation_Abbreviation: DEM Source_Contribution: Stratigraphic data from this source was used to generate an EarthVision grid that represented the elevation of the top of the Wyodak-Anderson coal zone in the Gillette coalfield study area. Source_Information: Source_Scale_Denominator: 250,000 Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19950000 Source_Currentness_Reference: Publication Date Source_Citation_Abbreviation: DEM Source_Contribution: This source provided a grid of the elevation of the topography (surface elevation) in the area of the Gillette coalfield. Process_Step: Process_Description: Stratigraphic data were compiled into a relational database. These data were correlated and the coal and rock above, within, and below the Wyodak-Anderson (WA) coal zone were labeled. Stratigraphic data for the coal and rock units within the WA coal zone were downloaded from Stratifact. These data were loaded into a EarthVision (EV) software program. Along the edge of the WA coal extent, in areas where WA coal was known to be at the surface, elevation values (in ft) were assigned to node locations in the ARC/INFO coal extent polygon coverage. Surface elevations for the nodes were obtained from a U.S. Geological Survey Digital Elevation Model (DEM). These control points were added to the EV data set in the elevation of the top of the zone field. The elevation at the top of the zone was then gridded in EV using the normal minimum tension grid option, four multiple data points (number of closest control points used for calculating a grid value), and a 500 x 500-meter grid spacing. The ARC/INFO DEM coverage (with 500 x 500-meter data spacing) was imported into EV, defined as a grid file, and clipped to the same lateral extent as the EV grid of the top of the coal zone. Using the EV formula processor, the top of the coal zone grid was subtracted from the surface elevation (DEM) grid to create a (minimum) overburden grid. An isopach map was then generated from this grid, with a constant contour interval of 100 ft, and saved to a file in ASCII format. The ASCII file was modified using a custom program called ismarc. The modified file was imported into ARC/INFO and generated as a polygon coverage using an Arc Macro Language (AML). The AML clipped the coverage to the study extent and assigned the overburden thickness polygons with values that are the average of the values of the bounding isopach lines (for example, a polygon defined by isopach lines of 100 and 200 ft was assigned an overburden thickness attribute of 150 ft). A new item was then added to the polygon attribute table and populated with text labels corresponding more closely to overburden categories that we were to use for coal resource tables and graphic display (0-100 ft, 100-200 ft, 200-300 ft, 300-400 ft, 400-500 ft, 500-1,000 ft, and 1,000-2,000 ft). The polygon coverage was then dissolved based on the text labels. The final coverage was projected to geographic and made into a shape file in ArcView. Process_Date: 19980000 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Energy Resources Team Contact_Person: Margaret Ellis Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303.236.7775 Contact_Electronic_Mail_Address: mellis@usgs.gov Hours_of_Service: Monday through Friday 8:00 AM- 3:00 PM Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains Point_and_Vector_Object_Count: 153 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: .0001 Longitude_Resolution: .0001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: gilovb.dbf Entity_Type_Definition: Shapefile Attribute Table Entity_Type_Definition_Source: None Attribute: Attribute_Label: Area Attribute_Definition: Area of polygon Attribute_Definition_Source: Software computed Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.00000 Range_Domain_Maximum: 0.14966 Attribute: Attribute_Label: Perimeter Attribute_Definition: Perimeter of polygon Attribute_Definition_Source: Software computed Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.00094 Range_Domain_Maximum: 7.83280 Attribute: Attribute_Label: Overburden Attribute_Definition: overburden categories Attribute_Definition_Source: User Defined Attribute_Domain_Values: Unrepresentable_Domain: Character field Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Energy Resources Team Contact_Address: Address_Type: mailing address Address: Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303.236.1647 Hours_of_Service: Monday through Friday, 8:00 AM- 3:00 PM Distribution_Liability: The US Geological Survey provides these geographic data "as is." The USGS makes no guarantee or warranty concerning the accuracy of information contained in this geographic data. The USGS further makes no warranties, either expressed or implied as to any other matter whatsoever, including, without limitation, the condition of the product, or its fitness for any particular purpose. The burden for determining fitness for use lies entirely with the user. Although these data have been processed successfully on USGS computers, no warranty, expressed or implied, is made by the USGS regarding the use of these data on any other system, nor does the fact of distribution constitute or imply any such warranty. In no event shall the USGS have any liability whatsoever for payment of any consequential, incidental, indirect, special, or tort damages of any kind, including, but not limited to, any loss of profits arising out of use of or reliance on the geographic data or arising out of the delivery, installation, operation, or support by the USGS. Metadata_Reference_Information: Metadata_Date: 19980000 Metadata_Review_Date: 19990000 Metadata_Future_Review_Date: 19990000 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Energy Resources Team Contact_Person: Margaret Ellis Contact_Position: Geologist Contact_Address: Address_Type: mailing address Address: Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303.236.7775 Contact_Electronic_Mail_Address: mellis@usgs.gov Hours_of_Service: Monday through Friday 8:00 AM- 3:00 PM Metadata_Standard_Name: FGDC CSDGM Metadata_Standard_Version: 19940608