Geologic Map of the McGrew Spring 7.5' Quadrangle, Cochise County, Arizona

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Frequently-anticipated questions:

What does this data set describe?
    Title:
    Geologic Map of the McGrew Spring 7.5' Quadrangle, Cochise County, Arizona
    Abstract:
    The McGrew Springs 7.5' Quadrangle is located in northwestern Cochise County about 45 miles southeast of Tucson, Arizona and lies south of the town of Benson. The western portion of the map encompasses a portion of the eastern flank of the Whetstone Mountains which is part of the Coronado National Forest. Kartchner Caverns State Park is located in the northeast corner of the map. The majority of the map area is covered by Quaternary fan and Tertiary basin fill deposits. Bedrock and surficial geology in the study area were mapped between October, 2002 and June, 2003 as part of a multiyear mapping program directed at producing geologic map coverage for the Karchner Caverns State Park and surrounding areas. Quaternary and late Tertiary deposits in the McGrew Springs 7.5' Quadrangle were partially mapped by Gray (1965) however this map does not separate the quaternary deposits from each other. Multiple phases of Quaternary alluvial fans top late Tertiary valley fill. Large outcrops of valley fill are exposed in the southeastern portion of the map which could be related to structure, however, there was no direct evidence for this structure in the mapped deposits.
    Supplemental_Information:
    The mapping was done under the joint State-Federal STATEMAP program, as specified in the National Geologic Mapping Act of 1992, and was jointly funded by the Arizona Geologic Survey and the U.S. Geological Survey under STATEMAP Program Contract #02HQAG0016. The view and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.

  1. How should this data set be cited?

    Shipman, Todd C. , and Ferguson, Charles A. , 20031219, Geologic Map of the McGrew Spring 7.5' Quadrangle, Cochise County, Arizona: Arizona Geological Survey Digital Geologic Map DGM-35, Arizona Geological Survey, Tucson, AZ.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -110.375
    East_Bounding_Coordinate: -110.25
    North_Bounding_Coordinate: 31.875
    South_Bounding_Coordinate: 31.75

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 19-Dec-2003
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: Map

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a raster data set.

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 12
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -111.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using Coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in Meters

      The horizontal datum used is North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4000000.
      The flattening of the ellipsoid used is 1/294.978698.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview:
    This dataset consists of 1 Adobe® PDF file, 1 jpg and 1 Postscript file that represents the geologic map with associated collar text. The map is a detailed, 1:24,000 layout scale geologic map of a portion of the Whetstone Mountains and Kartchner Caverns area.
    Entity_and_Attribute_Detail_Citation: n/a

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Arizona Geological Survey
    GIS Technician or GIS Manager
    416 W. Congress St., # 100
    Tucson, Arizona 85701
    U.S.A.

    520-770-3500 (voice)
    520-770-3505 (FAX)

    Hours_of_Service: 8:00 a.m to 5:00 p.m., M-F

Why was the data set created?
The intention of this investigation is a multiyear mapping program directed at producing geologic map coverage for the Karchner Caverns State Park and surrounding San Pedro River areas. The primary product resulting from new mapping in the study area is a 1:24000 layout-scale geologic map describing rock units and other geologic features.

How was the data set created?
  1. From what previous works were the data drawn?

    Shipman (source 1 of 3)
    Shipman, Todd C., 2003, unpublished field sheets (published here).

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution: map of surficial geology

    Ferguson (source 2 of 3)
    Ferguson, Charles A., 2003, unpublished field sheets (published here).

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution: map of bedrock geology

    aerial photographs (source 3 of 3)
    photographs, aerial, 20031219, published aerial photographs, DOQQs and other aerial photos.

    Type_of_Source_Media: photographs
    Source_Scale_Denominator: 24000
    Source_Contribution: aerial photographs of ground condition at time of flight

  2. How were the data generated, processed, and modified?

    Date: 19-Dec-2003 (process 1 of 1)
    (1) Bedrock geology was hand drafted in the field onto a topographic base; (2) Field sheets were scanned on a table-top scanner; (3) Scans were registered and rectified using ArcGIS 8.3 software; (4) Scans were digitized on-screen and edited as multiple layers using ArcMap; (5) Layers were attributed using ArcMap 8.3; (6) Surficial geology was mapped in the office on mylar over photos; (7) Surficial geology was field verified; (8) Mylar overlays and photos were scanned on a table-top scanner; (9) Scans were rectified using ERDAS Imagine 8.4 and 1992 DOQQ's; (10) Scans were digitized on-screen using ArcMap 8.3; (11) Line locations were adjusted using ArcMap 8.3; (12) Surficial coverage was merged with bedrock coverage; (15) Map unit colors and other cartographic symbology were imported from a palette created in ArcMap; (16) Layouts with associated collar text were created using ArcMap; (17) Layouts were printed to Postscript files then converted to PDF files using Adobe Distiller.

    Person who carried out this activity:

    Arizona Geological Survey
    GIS Technician
    416 W. Congress St., # 100
    Tucson, Arizona 85701
    U.S.A.

    520-770-3500 (voice)
    520-770-3505 (FAX)

    Hours_of_Service: 8:00 a.m to 5:00 p.m., M-F
    Data sources used in this process:
    • Shipman
    • Ferguson
    • aerial photographs

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    Although no formal tests were performed, all attribution was tested for accuracy against the paper source maps from which the source dataset was digitized by direct visual comparison between the source maps and the digital dataset.

  2. How accurate are the geographic locations?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Data completeness reflects the content of the source maps.

  5. How consistent are the relationships among the observations, including topology?

    All attributes are logically consistent.

How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints: Not to be reproduced for commercial purposes

  1. Who distributes the data set? (Distributor 1 of 1)

    Arizona Geological Survey
    Publication Sales Department
    416 W. Congress St., # 100
    Tucson, Arizona 85701
    U.S.A.

    520-770-3500 (voice)
    520-770-3505 (FAX)

    Hours_of_Service: 8:00 a.m to 5:00 p.m., M-F
  2. What's the catalog number I need to order this data set?

    AZGS DGM-35: Geologic Map of the McGrew Spring 7.5' Quadrangle, Cochise County, Arizona

  3. What legal disclaimers am I supposed to read?

    Although these data have been processed successfully on a computer system at the Arizona 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. It is strongly recommended that these data are directly acquired from the Arizona Geological Survey, and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The Arizona Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 19-Dec-2003

Metadata author:
Arizona Geological Survey
GIS Technician
416 W. Congress St., # 100
Tucson, Arizona 85701
U.S.A.

520-770-3500 (voice)
520-770-3505 (FAX)

Hours_of_Service: 8:00 a.m to 5:00 p.m., M-F
Metadata standard:
FGDC CSDGM (FGDC-STD-001-1998)

Generated by mp version 2.7.33 on Fri Dec 19 09:45:46 2003