Identification_Information: Citation: Citation_Information: Originator: United States Geological Survey (USGS) Central Region Energy Resources Team Publication_Date: 19990930 Title: Kncat.shp (Net coal thickness map for the Knobloch coal resource unit, Ashland coalfield, Montana) Publication_Information: Publication_Place: Denver, CO Publisher: USGS Central Region Energy Resources Team Description: Abstract: This ArcView shapefile contains a polygon representation of the net coal thickness of the Knobloch coal resource unit, Ashland coalfield, Montana. This theme was created specifically for the National Coal Resources 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). Supplemental_Information: The net coal thickness map theme represents a digital polygon coverage of the net coal thickness (isopach) map for the Knobloch coal resource unit. As defined here, the "Knobloch coal resource unit" represents the single, thick bed of coal formed by the merging of multiple coal beds in northern areas of the coal field as well as representing the uppermost coal bed in the "Knobloch coal zone" where the thick coal bed has split into multiple coal beds in southern, western, and eastern areas of the coal field. In all cases, the Knobloch coal resource unit represents a single coal bed. The original net coal isopach map for the Knobloch coal resource unit was constructed by contouring a gridded data set of values representing the net coal thickness (excluding partings) for the Knobloch coal resource unit in each drill hole and at each outcrop location. The map extent used for the net coal isopach map of the Knobloch coal resource unit is constrained by the outcrop (or clinker contact) of the Knobloch coal bed, and by the northern, eastern, and southern boundaries of 7.5' quadrangle maps within the coal field. 202 data points (drill-hole and outcrop locations) were used in the calculation of the net coal isopach map of the Knobloch coal resource unit. The drill hole and outcrop data were imported into a gridding and contouring software package (EarthVision; Dynamic Graphics, Inc.). An isopach (equal thickness) grid was calculated and used to generate the net coal isopach map. The grid spacing used in this calculation was 200 x 200 meters and the grid extent covers an area of approximately 332,000 acres (519 square miles). Minor editing of the grid file was necessary to generate results more consistent with our interpretations of the coal geology in the study area. Upon completion of the edits, the isopach map was converted to a contour output file in EarthVision, and subsequently converted into a digital polygon coverage by using a combination of programs ('ISMARC' and 'CONVERT-ISM.AML') furnished to the U.S. Geological Survey by the Illinois State Geological Survey. This net coal isopach coverage was then generalized using a weed tolerance of 30 meters to reduce file size. The generalized cover was then converted to a shapefile for incorporation as a theme in the ARCVIEW project. The net coal thickness categories as shown in the theme (for example, 2.5 - 5.0 ft, 5.0 - 10 ft, etc.) are consistent with total coal thickness categories used in the tabulation of coal resources. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19990000 Currentness_Reference: Publication Date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -106.6250 East_Bounding_Coordinate: -106.0000 North_Bounding_Coordinate: 45.6860 South_Bounding_Coordinate: 45.2500 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Net Coal Thickness Theme_Keyword: Knobloch Coal Resource Unit Theme_Keyword: Net Coal Isopach Map Theme_Keyword: Northern Rocky Mountain and Great Plains Fort Union Coal Resources Assessment Place: Place_Keyword_Thesaurus: None Place_Keyword: Ashland Coalfield Place_Keyword: Montana Place_Keyword: Rosebud County Place_Keyword: Powder River County Place_Keyword: Powder River Basin Place_Keyword: Northern Rocky Mountain and Great Plains Fort Union Coal Resources Assessment Access_Constraints: None Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Central Region Energy Resources Team Contact_Person: Steve Roberts 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: 303.236.7788 Native_Data_Set_Environment: SUNOS, 5.51 SUN4d UNIX ArcView version 3.0 ARC/INFO version 7.1.2 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: No test for accuracy was performed. Logical_Consistency_Report: Polygon features present Completeness_Report: Net coal thickness interpretations are restricted to the Knobloch coal resource unit, Ashland coalfield, as defined in the USGS National Coal Resource Assessment project. This coverage does not include all areas in which the Knobloch coal resource unit is present in the northern part of the Powder River Basin. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Limited to software coordinates precision to geographic coordinates. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: USGS Central Region Energy Resources Team Publication_Date: Unknown Publication_Time: Unknown Title: Northern Rocky Mountain and Great Plains Fort Union Stratifact Database. Geospatial_Data_Presentation_Form: map Type_of_Source_Media: Digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: Unknown Source_Currentness_Reference: Ground Condition Source_Citation_Abbreviation: None Source_Contribution: Not applicable Process_Step: Process_Description: Net coal thickness for the Knobloch coal resource unit was modeled using EarthVison (Dynamic Graphics, Inc.) software. 202 data points (drill hole and outcrop locations) were used in the calculation of the net coal isopach map of the Knobloch coal resource unit. The drill hole and outcrop data were imported into Earthvision, and an isopach (equal thickness) grid was calculated to generate the net coal isopach map. The grid spacing used in this calculation was 200 x 200 meters and the grid extent covers an area of approximately 332,000 acres (519 square miles). Minor editing of the grid file was necessary to generate results more consistent with our interpretations of the coal geology in the study area. Upon completion of the edits, the isopach map was converted to a contour output file in EarthVision, and subsequently converted into a digital polygon coverage by using a combination of programs ('ISMARC' and 'CONVERT-ISM.AML') furnished to the U.S. Geological Survey by the Illinois State Geological Survey. This net coal isopach coverage was then generalized using a weed tolerance of 30 meters to reduce file size. The generalized cover was then converted to a shapefile for incorporation as a theme in the ArcView project. Process_Date: 19990700 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Central Region Energy Resources Team Contact_Person: Steve Roberts 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 Contact_Voice_Telephone: 303.236.7788 Contact_Electronic_Mail_Address: sroberts@usgs.gov 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: 7 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: kncat.dbf Entity_Type_Definition: Shapefile Attribute Table Entity_Type_Definition_Source: None Attribute: Attribute_Label: Thickness Attribute_Definition: Coal thickness in ft. Attribute_Definition_Source: User Defined Attribute_Domain_Values: Unrepresentable_Domain: Character field Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Central Region 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 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: 19990000 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Central Energy Team Contact_Person: Steve Roberts Contact_Address: Address_Type: mailing address Address: Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303.236.7788 Metadata_Standard_Name: FGDC CSDGM Metadata_Standard_Version: 19940608