Identification_Information:
	Citation:
		Citation_Information:
			Originator: USGS Central Region Energy Resources Team
			Publication_Date: 19990930
			Title: Knovb.shp ( Coal Overburden Thickness of Knobloch Coal Zone)
			Publication_Information:
				Publication_Place: Denver, CO
				Publisher: USGS Central Region Energy Resources Team
	Description:
		Abstract:
			This ArcView shapefile is a polygon representation of the
			overburden thickness above the Knobloch coal resource
			unit in the Powder River Basin. 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 stored in standardized formats,
			and being analyzed using a Geographic Information
			System (GIS).
		Supplemental_Information:
			The overburden thickness map theme represents a digital
			polygon coverage of the overburden isopach (thickness)
			map for the Knobloch coal resource unit.
			The overburden isopach map represents the
			thickness of rock overlying the top of the Knobloch coal
			resource unit. The map extent used for the overburden
			isopach map 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.
			The overburden interpretations were derived by
			first developing a grid representing the top of the Knobloch
			coal resource unit using a commercial gridding and
			contouring software package (EarthVision; Dynamic
			Graphics, Inc.).  This grid, which was calculated using a
			grid spacing of 200 x 200 meters, was then subtracted from
			a composite Digital Elevation Model (DEM) grid of
			topographic elevation for the entire Ashland coal field,
			resulting in a grid of thickness values that could then be
			contoured as overburden thickness isopachs.  Multiple 2
			arc-second DEMs were merged using
			the 'mosaic' command in ARC/INFO to create the
			composite DEM used in the overburden calculations.
			The overburden isopach map was then
			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
			overburden 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
			overburden thickness categories included in the theme (for
			example, 0 - 100 ft, 100 - 200 ft, etc.) are consistent with
			overburden thickness categories used in the tabulation of
			total 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: Overburden
			Theme_Keyword: Knobloch coal resource unit
		Place:
			Place_Keyword_Thesaurus: None
			Place_Keyword: Montana
			Place_Keyword: Rosebud County
			Place_Keyword: Powder River County
			Place_Keyword: Ashland Coalfield
			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:
		ArcView version 3.0
		ARC/INFO 7.1.2
		SUNOS 5.6 Sun4U, UNIX
Data_Quality_Information:
	Attribute_Accuracy:
		Attribute_Accuracy_Report: No tests were performed
	Logical_Consistency_Report: Polygon features present
	Completeness_Report:
		Overburden is limited to Knobloch Coal Resource Unit in
		the Ashland coalfield.
	Positional_Accuracy:
		Horizontal_Positional_Accuracy:
			Horizontal_Positional_Accuracy_Report:
				Limited to software coordinate precision fo geographic
				coordinates
	Lineage:
		Source_Information:
			Source_Citation:
				Citation_Information:
					Originator: USGS Central Region Energy Resource (Tertiary 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:
				The overburden map was generated from data and
				interpretations compiled by the USGS Central
				Region Energy Team.  This coverage was applied to coal
				resource calculations for the Knobloch coal resource unit
				as defined in the National Coal Resource Assessment
				project of the USGS.
		Process_Step:
			Process_Description:
				The overburden interpretations were derived by first
				developing a grid representing the top of the Knobloch
				coal
				resource unit using a commercial gridding and contouring
				software package (EarthVision; Dynamic Graphics, Inc.).
				This grid, which was calculated using a grid spacing of 200
				x 200 meters, was then subtracted from a composite Digital
				Elevation Model (DEM) grid of topographic elevation for
				the
				entire Ashland coal field, resulting in a grid of thickness
				values that could then be contoured as overburden
				thickness isopachs.  Multiple 2 arc-second DEMs with a
				resolution of approximately 60 meters (or about a scale of
				100,000) were merged using the 'mosaic' command in
				ARC/INFO to create the composite DEM used in the
				overburden calculations.
				The overburden isopach map was then 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
				overburden 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
				overburden thickness categories included in the theme (for
				example, 0 - 100 ft, 100 - 200 ft, etc.) are consistent with
				overburden thickness categories used in the tabulation of
				total coal resources.
			Process_Date: 19990000
			Process_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
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: 344
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: knovb.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: 0.000
					Range_Domain_Maximum: 0.031
		Attribute:
			Attribute_Label: Perimeter
			Attribute_Definition: Perimeter of polygon
			Attribute_Definition_Source: Software computed
			Attribute_Domain_Values:
				Range_Domain:
					Range_Domain_Minimum: 0.001
					Range_Domain_Maximum: 9.803
		Attribute:
			Attribute_Label: Overburden
			Attribute_Definition: Overburden Thicknes
			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 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
	Metadata_Standard_Name: FGDC CSDGM
	Metadata_Standard_Version: 19940608