Identification_Information:
  Citation:
    Citation_Information:
      Originator: David V. Smith
      Originator: Robert R. McDougal
      Publication_Date: 2007
      Title: Boundaries of Interpreted Igneous Intrusives from Airborne Magnetic Data, Uvalde, Medina, and Bexar County, Texas
      Edition: 1.0
      Geospatial_Data_Presentation_Form: vector digital data
      Series_Information:
        Series_Name: Digital Data for Scientific Investigations Report 2007-5191
        Issue_Identification: sir2007_xxx_intrusives_edwards
      Publication_Information:
        Publication_Place: Denver, Colorado
        Publisher: U.S. Geological Survey
      Online_Linkage: http://pubs.usgs.gov/sir/2007/5191/
      Larger_Work_Citation:
        Citation_Information:
          Originator: David V. Smith
          Originator: Robert R. McDougal
          Publication_Date: Unpublished Material
          Publication_Time: Unknown
          Title: Distribution of Igneous Rocks in Medina and Uvalde Counties, Texas, as Inferred from Aeromagnetic Data
          Geospatial_Data_Presentation_Form: document
          Series_Information:
            Series_Name: Scientific Investigations Report
            Issue_Identification: 2007-5191
          Publication_Information:
            Publication_Place: Denver, Colorado
            Publisher: U.S. Geological Survey
          Online_Linkage: http://pubs.usgs.gov/sir/2007/5191/
  Description:
    Abstract: The outlines of igneous rock occurance were produced from the 2001 aeromagnetic data by separating shallow equivalent sources using matched bandpass filtering with layer depth of 264 meters.  The shallow source layer was processed to obtain a horizontal gradient grid, which was contoured using a threshold set by interpretive modeling of isolated, discrete anomalies.  Closed contours corresponding to validated anomalies were included in the final transparancy layer.
    Purpose: The distribution and aereal extent of igneous rocks in the Edwards aquifer are of interest in understanding the influence of igneous intrusive rocks on the limestone aquifer at regional and local scales.
    Supplemental_Information:
      This electronic report was subjected to the same review standard that applies to all U.S. Geological Survey reports. Reviewers were asked to check the topological consistency, tolerances, attribute frequencies and statistics, projection and geographic extent. The reviewers checked the metadata and readme files for completeness and accuracy.

      Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology.

      Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  Time_Period_of_Content:
    Time_Period_Information:
      Single_Date/Time:
        Calendar_Date: 2007
    Currentness_Reference: publication date
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: None planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -100.028693
      East_Bounding_Coordinate: -98.814996
      North_Bounding_Coordinate: 29.623855
      South_Bounding_Coordinate: 29.208850
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: American Geological Institute Glossary of Geology
      Theme_Keyword: Airborne magnetic data
      Theme_Keyword: Igneous intrusives
      Theme_Keyword: Aeromagnetic data
      Theme_Keyword: Magnetic anomalies
      Theme_Keyword: Edwards aquifer
    Place:
      Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
      Place_Keyword: Texas
      Place_Keyword: Uvalde County
      Place_Keyword: Medina County
      Place_Keyword: Bexar County
  Access_Constraints: none
  Use_Constraints: none
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: David V. Smith
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Geophysicist
      Contact_Address:
        Address_Type: mailing and physical address
        Address: Denver Federal Center, MS973, bldg. 20
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80225
        Country: USA
      Contact_Voice_Telephone: 303-236-1228
      Contact_Facsimile_Telephone: 303-236-1425
      Contact_Electronic_Mail_Address: dvsmith@usgs.gov
  Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: Attributes vaules were calculated using a GIS and are considered accurate. In addition, attributes were checked and evaluated as part of the review process associated with the publication of the source report.
  Logical_Consistency_Report: Lines forming polygons join at endpoints to completely enclose defined areas. No duplicate polygon features or pseudo nodes exist. Nodes are represented by a single coordinate pair that indicates the starting and (or) ending point of the line forming the polygon. All vertices that define the shapes of the polygons are represented by unique coordinate pairs.
  Completeness_Report: Digitized all of aeromag map. 100% complete.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: The accuracy of the compiled digital line features in the data set is based upon the accuracy of source maps and digital data sets which generally are compiled to meet National Map Accuracy Standards. Horizontal positional accuracy was tested by visually comparing these line features to source maps using a GIS and hardcopy plots.
  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: Miggins, Daniel P.
          Originator: Blome, Charles D.
          Originator: Smith, David V.
          Publication_Date: 2004
          Title: Preliminary 40Ar/39Ar geochronology of igneous intrusions from Uvalde County, Texas: Defining a more precise eruption history for the southern Balcones Volcanic Province
          Geospatial_Data_Presentation_Form: document
          Series_Information:
            Series_Name: Open-File Report
            Issue_Identification: 2004-1031
          Publication_Information:
            Publication_Place: Denver, Colorado
            Publisher: U.S. Geological Survey
          Other_Citation_Details: Figure 2 (B)
          Online_Linkage: http://pubs.er.usgs.gov/usgspubs/ofr/ofr20041031
      Source_Scale_Denominator: 250000
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 2004
        Source_Currentness_Reference: publication date
      Source_Citation_Abbreviation: Smith and others, 2004
      Source_Contribution: Source map
    Process_Step:
      Process_Description: The final interpretive map was produced by creating two overlapping GIS layers. First, the contours identified as shallow igneous bodies were digitized as polygons and attributed as to geographic location and area using the software package ERDAS Imagine v. 8.6 (Leica Geosystems LLC). The GIS coverage was topologically "built" and saved as an ARC coverage (ARC interchange format) and shapefile. Next, the topographic base map was created by mosaicking two U.S.G.S. 1:250,000 scale contour maps of San Antonio and Del Rio, Texas (UTM zone 14, North American Datum 1927). The digital mosaic was georeferenced using fifty control points evenly distributed throughout the image and a second order polynomial warp method. Finally, the coverage of igneous intrusions was adjusted to a transparency of fifty percent and overlaid on the georeferenced digital base map.
      Source_Used_Citation_Abbreviation: Smith and others, 2004
      Process_Date: 2007
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Robert R. McDougal
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Geologist
          Contact_Address:
            Address_Type: mailing and physical address
            Address: Denver Federal Center, MS964D, bldg. 20
            City: Denver
            State_or_Province: Colorado
            Postal_Code: 80225
            Country: USA
          Contact_Voice_Telephone: 303-236-1854
          Contact_Facsimile_Telephone: 303-236-3200
          Contact_Electronic_Mail_Address: rmcdouga@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: G-polygon
      Point_and_Vector_Object_Count: 390
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Grid_Coordinate_System:
        Grid_Coordinate_System_Name: Universal Transverse Mercator
        Universal_Transverse_Mercator:
          UTM_Zone_Number: 14
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: 0.999600
            Longitude_of_Central_Meridian: -99.000000
            Latitude_of_Projection_Origin: 0.000000
            False_Easting: 500000.000000
            False_Northing: 0.000000
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: coordinate pair
        Coordinate_Representation:
          Abscissa_Resolution: 100
          Ordinate_Resolution: 100
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1927
      Ellipsoid_Name: Clarke 1866
      Semi-major_Axis: 6378206.400000
      Denominator_of_Flattening_Ratio: 294.978698
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: Aeromagnetic anomalies
      Entity_Type_Definition: Aeromag anomalies interpreted as Igneous Intrusions for the Edwards Aquifer
      Entity_Type_Definition_Source: Metadata author
    Attribute:
      Attribute_Label: FID
      Attribute_Definition: Internal feature number.
      Attribute_Definition_Source: Environmental Systems Research Institute, Inc. (ESRI)
      Attribute_Domain_Values:
        Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
    Attribute:
      Attribute_Label: Shape
      Attribute_Definition: Feature geometry.
      Attribute_Definition_Source: ESRI
      Attribute_Domain_Values:
        Unrepresentable_Domain: Coordinates defining the features.
    Attribute:
      Attribute_Label: AREA
      Attribute_Definition: Area of intrusive (in meters squared)
      Attribute_Definition_Source: Metadata author
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 21610.59
          Range_Domain_Maximum: 9128956.5
          Attribute_Units_of_Measure: Meters
    Attribute:
      Attribute_Label: PERIMETER
      Attribute_Definition: Perimeter of intrusive (in meters)
      Attribute_Definition_Source: metadata author
      Attribute_Domain_Values:
        Range_Domain:
          Range_Domain_Minimum: 596.96
          Range_Domain_Maximum: 29619.77
          Attribute_Units_of_Measure: meters
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey
      Contact_Address:
        Address_Type: physical address
        Address: Denver Federal Center
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80225
        Country: USA
      Contact_Voice_Telephone: 1-888-275-8747
      Contact_Electronic_Mail_Address: <http://ask.usgs.gov/>
  Resource_Description: Downloadable Data
  Distribution_Liability: Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. These data should be directly acquired from a U.S. Geological Survey server, and not indirectly through other sources that may have altered the data in some way.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: Shapefile
        Format_Version_Number: ARC Version 9.x
        File_Decompression_Technique: no compression applied
        Transfer_Size: 0.128
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://pubs.usgs.gov/sir/2007/5191/
    Fees: none
Metadata_Reference_Information:
  Metadata_Date: 20070607
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Robert R. McDougal
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Geologist
      Contact_Address:
        Address_Type: mailing and physical address
        Address: Denver Federal Center
        Address: MS964D
        Address: bldg. 20
        City: Denver
        State_or_Province: Colorado
        Postal_Code: 80225
        Country: USA
      Contact_Voice_Telephone: 303-236-1854
      Contact_Facsimile_Telephone: 303-236-3200
      Contact_Electronic_Mail_Address: rmcdouga@usgs.gov
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: local time
  Metadata_Access_Constraints: none
  Metadata_Use_Constraints:
    Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data.

    Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcGIS format, this metadata file may include some ArcGIS-specific terminology.
  Metadata_Extensions:
    Online_Linkage: http://www.esri.com/metadata/esriprof80.html
    Profile_Name: ESRI Metadata Profile