Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey, Central Energy Resources Team Originator: Johnson, E.A. Originator: Roberts, L.N.R. Originator: Brownfield, M.E. Publication_Date: 2000 Title: yam*_thk (Isopachs of total net coal in A-D coal zones, Yampa Coal Field) Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Denver, CO USA Publisher: U.S. Geological Survey Other_Citation_Details: In subdir 500k (defines appropriate maximum scale for data use) chap. P, Geology and resource assessment of the middle and upper coal groups in the Yampa coal field, northwestern Colorado Larger_Work_Citation: Citation_Information: Originator: Kirschbaum, M.A. Originator: Roberts, L.N.R. Originator: Biewick, L.R.H. Publication_Date: 2000 Title: Geologic Assessment of Coal in the Colorado Plateau Series_Information: Series_Name: U.S. Geological Survey Professional Paper Issue_Identification: 1625-B Publication_Information: Publication_Place: Denver, CO Publisher: U.S. Geological Survey Description: Abstract: These are shapefiles and ARC/INFO polygon coverages showing the isopachs of total net coal in beds greater than or equal to 1.2' thick for the A, B, C, and D coal zones in the Williams Fork Formation, Yampa coal field, northwestern Colorado. YAMA_THK is for the A coal zone, YAMB_THK is for the B coal zone, etc. Purpose: The Nation's coal resources are being reassessed 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 century. This assessment is different from previous large-scale USGS assessments because files and databases are being stored in a digital format and are being analyzed using a Geographic Information System (GIS). Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19970000 Ending_Date: 19980000 Currentness_Reference: Processing Date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -107.8897 East_Bounding_Coordinate: -106.9577 North_Bounding_Coordinate: 40.6013 South_Bounding_Coordinate: 40.2496 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Coal Theme_Keyword: National Coal Resource Assessment (NCRA) Theme_Keyword: Colorado Plateau Theme_Keyword: Isopachs of coal Theme_Keyword: coal thickness Place: Place_Keyword_Thesaurus: None Place_Keyword: Colorado Place_Keyword: Sandwash Basin Place_Keyword: Green River Basin Place_Keyword: Rio Blanco County Place_Keyword: Moffat County Place_Keyword: Routt County Place_Keyword: Yampa coal field Stratum: Stratum_Keyword_Thesaurus: Geologic Names Unit Lexicon (GNULEX) Stratum_Keyword: Mesaverde Group Stratum_Keyword: Williams Fork Formation Stratum_Keyword: Iles Formation Stratum_Keyword: Trout Creek Sandstone Mbr. Stratum_Keyword: Twentymile Sandstone Mbr. Access_Constraints: None Use_Constraints: Appropriate maximum scale for data use is 500k. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Central Energy Contact_Person: Johnson, E.A. Contact_Address: Address_Type: mailing and physical address Address: PO Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303.236.4857 Security_Information: Security_Handling_Description: None Security_Classification: Unclassified Security_Classification_System: None Native_Data_Set_Environment: SunOS, 5.5.1, sun4d UNIX, ARC/INFO version 7.0.4 and ArcView 3.1 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: See Entity_Attribute_Information Logical_Consistency_Report: Polygon topology present. Completeness_Report: Complete Lineage: Process_Step: Process_Description: Initial queries of the Stratifact database were made for only those records that contain data on each of the four coal zones resulting in four separate files (subsets) of the database. These were input files for a parting/split program. This program, written at the USGS, determines whether a rock unit between two coal units is a parting in a coal bed or if the rock unit splits two separate coal beds as defined in (Wood and others, 1983, p. 36). Coal units are combined to form a single bed if the thickness of rock between them is thinner than the coal on either side. If the rock is thinner it is considered to be a parting and if it is thicker it is considered to be a split. After the program calculates the thickness of coal in each coal bed it determines if the coal beds are greater than the minimum thickness requirement as a resource. For coals of bituminous rank, this minimum thickness is 1.2 ft. (Wood and others, 1983, p.34). Coals in the Yampa coal area are bituminous in rank. The program goes through another process where it sums coal bed thickness of only the coal beds that are greater than or equal to the minimum thickness (1.2'). The program outputs a single line of data for each location with net coal thickness and x, y location parameters. The data output from this program also contains a column designating the number of coal beds that were added to arrive at the net coal thickness. Output files from the parting/split program were introduced into EarthVision (EV) as scattered data files and projected into Lambert Conformal Conic projection. Locations with a net coal thickness value of zero were appended to the scattered data file (applicable only to the B and C coal zones) to control extrapolation during gridding. These scattered data files were then gridded in EV using the 'minimum tension grid' option. The isopach maps for each coal zone were plotted in EV with a contour interval that best-depicts the coal thickness distribution with an added contour line for 1.2 ft, if applicable. The contour lines were saved in contour output files. The contour output files were converted to files in 'arc generate' format using ISMARC and then converted to ARC/INFO polygon coverages using an Arc Macro Language program from the Illinois State Geological Survey. The coverages were converted to shapefiles using ArcView. Process_Date: 19980000 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: 22 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: yam*_thk.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: 0.087 Attribute: Attribute_Label: Perimeter Attribute_Definition: Perimeter of polygon Attribute_Definition_Source: Software computed Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.027 Range_Domain_Maximum: 3.030 Attribute: Attribute_Label: Depth Attribute_Definition: Net coal thickness in beds greater than or equal to 1.2 ft. Attribute_Definition_Source: User Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 10.00 Range_Domain_Maximum: 90.00 Attribute: Attribute_Label: Depth2 Attribute_Definition: Net coal thickness in beds greater than or equal to 1.2 ft. Attribute_Definition_Source: User Defined Attribute_Domain_Values: Unrepresentable_Domain: Character field Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Central Energy Contact_Address: Address_Type: mailing and physical address Address: PO Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303.236.4608 Resource_Description: Shapefile and ARC/INFO coverage Distribution_Liability: Any use of trade, product, or company names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the USGS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. This data is not a legal document and is not intended to be used as such. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ARC/INFO coverage, export file and shapefile Format_Version_Number: ARC/INFO 7.0.4, ArcView 2.1 Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Format: ISO 9660 Fees: none Technical_Prerequisites: need ARC/INFO 7.0.4 or greater and/or ArcView 2.1 or greater and/or ArcExplorer (which can be downloaded free from ) and/or other software that can read ARC/INFO coverages, ARC/INFO export files, and/or shapefiles Metadata_Reference_Information: Metadata_Date: 19990203 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Central Energy Contact_Address: Address_Type: mailing and physical address Address: PO Box 25046 MS 939 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303.236.4608 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: None Metadata_Security_Information: Metadata_Security_Handling_Description: None Metadata_Security_Classification: Unclassified Metadata_Security_Classification_System: None ------------------------------------------------------------------------ Generated by mp version 2.4.8 on Mon Sep 27 14:11:07 1999