Metadata: Identification_Information: Citation: Citation_Information: Originator: Duval, Joseph S. Originator: Reed, John C. Originator: Zietz, Isadore Publication_Date: 2000 Title: Gamma-ray, Magnetic, and Topographic Data for the Colorado Front Range Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: USGS Open-File Report Issue_Identification: 2000-331 Publication_Information: Publication_Place: Reston, Virginia Publisher: U.S. Geological Survey Description: Abstract: The grid files presented here are in ASCII format that uses the definitions of the grid exchange format (GXF). The files can be viewed using a suitable word processing program. The different grids are: >Kfrco.gxf potassium concentrations in the rocks and soils >Ufrco.gxf uranium concentrations in the rocks and soils >Thfrco.gxf thorium concentrations in the rocks and soils >Magfrco.gxf residual magnetic field >Terrfrco.gxf digital elevations The data used to create the potassium (K), uranium (U), thorium (Th), and magnetic (Mag) grids were obtained as part of the National Uranium Resource Evaluation (NURE) Program of the U.S. Department of Energy (USDOE). The NURE Program included aerial surveys that collected gamma-ray and magnetic data. The aerial surveys were flown at a nominal altitude of 122 meters above the ground. The aerial survey flightlines were generally flown east- west with north-south tielines. For the data covering the mountains of the Colorado Front Range, the flightline spacing is 1 mile (1600 meters) for the east-west lines and about 8 miles (12.8 km) for the north-south tielines. For the data covering the plains to the east of the mountains, the flightline spacing is 3 miles (4800 m) for the east-west lines and about 16 miles (25.6 km) for the north-south tielines. In the mountains, helicopters were used with a detector volume of 2000 cubic inches (32.8 liters) of thallium doped sodium iodide (NaI(Tl)). Over the plains, fixed-wing aircraft were used with about 3300 cubic inches (54 liters) of NaI(Tl) detector. The magnetometers used were proton-precession magnetometers with base stations used to make diurnal corrections. The USDOE contracted with private contractors to conduct the aerial surveys and the contractors were responsible for all aspects of calibration and data processing. The data used to create the grid of digital elevations were derived from the U.S. Geological Survey (USGS) 1:250,000 topographic quadrangle maps. The topographic maps were digitized at intervals of three arc-seconds and were then averaged to intervals of 15 seconds. The resulting 15-second data were used to calculate the grid presented here. The units of the grid data are: >Potassium percent K >Uranium parts per million (ppm) eU >Thorium ppm eTh >Magnetic nano Teslas >Elevation meters Purpose: These data were originally obtained to aid in the estimate of uranium resources in the United States. Status: Progress: In Work Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -106 East_Bounding_Coordinate: -105 North_Bounding_Coordinate: 36 South_Bounding_Coordinate: 32 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Geophysical Data Place: Place_Keyword_Thesaurus: Geographic Names Information System Place_Keyword: Colorado Access_Constraints: None Use_Constraints: None Time_Period_of_Content: Currentness_Reference: publication date Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1978 Ending_Date: 1979 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The absolute accuracy of the concentrations of potassium, uranium, and thorium are estimated to be on the order of 20-30 percent. The accuracy of the magnetic data is about 2 nT. Because of the manner in which the elevation data have been averaged, the values should only be used in a qualitative manner. Completeness_Report: All of the available flightline data were used. Because of differences in the calibrations of the data sets, scaling adjustments were made to correct scaling differences. The following publication provides detailed information on the corrections made: Duval, J.S. and Riggle, F.E., 1999, Profiles of gamma-ray and magnetic data from aerial surveys over the conterminous United States: U.S. Geological Survey Digital Data Series DDS-31, Release 2, 3 CD-ROMs. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The position of the aircraft during the aerial surveys was constantly monitored. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 100 Horizontal_Positional_Accuracy_Explanation: meters, estimated Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The position of the aircraft during the aerial surveys was constantly monitored. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 100 Vertical_Positional_Accuracy_Explanation: meters, estimated Logical_Consistency_Report: The concentration data are based upon calibrations done using the airport calibration pads in Grand Junction, Colorado and the dynamic test strip at Lake Mead, Nevada. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Geometrics, Inc. Publication_Date: 1979 Title: Aerial gamma ray and magnetic survey; Rock Springs, Rawlins, and Cheyenne quadrangles, Wyoming and the Greeley Quadrangle, Colorado Geospatial_Data_Presentation_Form: document Series_Information: Series_Name: Open-File Report Issue_Identification: GJBX-17-79 Publication_Information: Publication_Place: Grand Junction, CO Publisher: U.S. Department of Energy Other_Citation_Details: 5 volumes Online_Linkage: None Type_of_Source_Media: paper Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19780101 Beginning_Time: Unknown Ending_Date: 19791231 Ending_Time: Unknown Source_Currentness_Reference: publication date Source_Contribution: These publications describe the aerial surveys, how they were flown, and data processing steps. Source_Citation_Abbreviation: USDOE, GJBX-17-79 Source_Information: Source_Citation: Citation_Information: Originator: Geometrics, Inc. Publication_Date: 1979 Title: Aerial gamma ray and magnetic survey; Rockies/Laramie Range Project; Denver and Pueblo quadrangles, Colorado Geospatial_Data_Presentation_Form: document Series_Information: Series_Name: Open-File Report Issue_Identification: GJBX-49-79 Publication_Information: Publication_Place: Grand Junction, CO Publisher: U.S. Department of Energy Other_Citation_Details: 4 volumes Online_Linkage: None Type_of_Source_Media: paper Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19780101 Beginning_Time: Unknown Ending_Date: 19791231 Ending_Time: Unknown Source_Currentness_Reference: publication date Source_Citation_Abbreviation: USDOE, GJBX-49-79 Source_Contribution: This report describes the aerial survey, how it was flown, and data processing steps. Process_Step: Process_Description: The flightline data were read from tape and were converted to grids using USGS gridding programs. Source_Used_Citation_Abbreviation: USDOE, GJBX-17-79 and GJBX-49-79 Process_Date: 1997 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph S. Duval Contact_Organization: U.S. Geological Survey Contact_Position: Geophysicist Contact_Address: Address_Type: mailing address Address: 12201 Sunrise Valley Drive Mail Stop 954 City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Voice_Telephone: (703) 648-6106 Contact_Facsimile_Telephone: (703) 648-6383 Contact_Electronic_Mail_Address: jduval@usgs.gov Contact_Instructions: email preferred Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Transverse Mercator Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -105 Latitude_of_Projection_Origin: 0 False_Easting: 0 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Row and Column Coordinate_Representation: Abscissa_Resolution: 0.635 Ordinate_Resolution: 0.635 Planar_Distance_Units: kilometers Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1927 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378.2064 Denominator_of_Flattening_Ratio: 294.98 Spatial_Data_Organization_Information: Indirect_Spatial_Reference: The data are located strictly by the coordinates. Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 539 Column_Count: 181 Vertical_Count: 1 Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS ESIC-Open-File Report Sales Contact_Address: Address_Type: mailing address Address: Mail Stop 517 U.S. Geological Survey Box 25286, Building 810 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0286 Country: USA Contact_Voice_Telephone: (303) 202-4210 Contact_Facsimile_Telephone: (303) 236-4031 Resource_Description: USGS Open-File Report 2000-331 Distribution_Liability: This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards (or with the North American Stratigraphic Code). 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: GXF Format_Version_Number: 1.0 Format_Information_Content: Colorado Front Range Potassium Transfer_Size: 850 kilobytes Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://geo-nsdi.er.usgs.gov/metadata/open-file/00-331/kfrco.gxf Digital_Form: Digital_Transfer_Information: Format_Name: GXF Format_Version_Number: 1.0 Format_Information_Content: Colorado Front Range Thorium Transfer_Size: 850 kilobytes Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://geo-nsdi.er.usgs.gov/metadata/open-file/00-331/thfrco.gxf Digital_Form: Digital_Transfer_Information: Format_Name: GXF Format_Version_Number: 1.0 Format_Information_Content: Colorado Front Range Uranium Transfer_Size: 850 kilobytes Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://geo-nsdi.er.usgs.gov/metadata/open-file/00-331/ufrco.gxf Digital_Form: Digital_Transfer_Information: Format_Name: GXF Format_Version_Number: 1.0 Format_Information_Content: Colorado Front Range magnetic anomaly Transfer_Size: 850 kilobytes Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://geo-nsdi.er.usgs.gov/metadata/open-file/00-331/magfrco.gxf Digital_Form: Digital_Transfer_Information: Format_Name: GXF Format_Version_Number: 1.0 Format_Information_Content: Colorado Front Range Elevation Transfer_Size: 850 kilobytes Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://geo-nsdi.er.usgs.gov/metadata/open-file/00-331/terrfrco.gxf Fees: none Metadata_Reference_Information: Metadata_Date: 20071119 Metadata_Review_Date: 20000606 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Peter N. Schweitzer Contact_Organization: U.S. Geological Survey Contact_Position: Geophysicist Contact_Address: Address_Type: mailing address Address: 12201 Sunrise Valley Drive Mail Stop 954 City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Voice_Telephone: (703) 648-6533 Contact_Facsimile_Telephone: (703) 648-6252 Contact_Electronic_Mail_Address: pschweitzer@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time with time differential factor Metadata_Access_Constraints: None Metadata_Use_Constraints: None