Preliminary geologic map of the Mesquite quadrangle, Clark and Lincoln Counties, Nevada and Mohave County, Arizona

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Preliminary geologic map of the Mesquite quadrangle, Clark and Lincoln Counties, Nevada and Mohave County, Arizona
Original geologic data mapped by the author in 1995 and 1996 with emphasis on structures in Miocene basin-fill deposits of the Muddy Creek Formation that may control availability and quality of groundwater.
Supplemental_Information: Compilation scale: 1:24000
  1. How might this data set be cited?
    Williams, Van S., 1996, Preliminary geologic map of the Mesquite quadrangle, Clark and Lincoln Counties, Nevada and Mohave County, Arizona: U.S. Geological Survey Open-File Report 96-676, U.S. Geological Survey, Denver, Colorado.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -114.125
    East_Bounding_Coordinate: -114.0
    North_Bounding_Coordinate: 36.875
    South_Bounding_Coordinate: 36.750
  3. What does it look like? (JPEG)
    Reduced-size image of the map sheet, 160x194 pixels, 13k bytes
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 24-Oct-1996
    publication date
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set.
    2. What coordinate system is used to represent geographic features?
      The map projection used is Transverse Mercator.
      Projection parameters:
      Scale_Factor_at_Central_Meridian: 0.9999
      Longitude_of_Central_Meridian: -115.567
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 0
      False_Northing: 0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.001
      Ordinates (y-coordinates) are specified to the nearest 0.001
      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 6378206.4.
      The flattening of the ellipsoid used is 1/294.98.
  7. How does the data set describe geographic features?
    The data is supplied in two formats. The first is the Microsoft-PC based native GSMCAD format and the second is a UNIX based ARC/INFO format.
    DATABASE FILES - GSMCAD (DOS) ====================================
    Text file of the description of map units and discussion of deposits, structure, and geologic history. Unit descriptions can be accessed by selecting map unit symbols displayed on screen.
    Mesquite.lsf, .ndx, and .nod
    The basic database components of line segment file, index file, and node file for the map. Units are degrees of latitude and longitude
    Unitlist.lsf, .ndx, and .nod
    The basic database components for the explanation sheet. Units are inches
    File of plotting parameters for the map
    File of plotting parameters for the explanation sheet
    File of projection parameters for the Transverse Mercator projection of the 1:24,000 scale 7 1/2 ' Mesquite topographic quadrangle basemap
    File of projection parameters for the Universal Transverse Mercator (zone 11) projection of a 1:100,000 scale 1 degree by 30 minute Overton sheet basemap. This can be used in GSMCAD to export UTM ground meters.
    Text file listing all map unit symbols
    Text file listing the explanations of the graphic symbols on the map
    Text file listing all the age names, headers, and other text used on the correlation of map units diagram, except for the map unit symbols
    Text file listing the names of map units
    Text file containing selected field notes that are linked to the observation points in the map database (code 197)
    Table of locations of selected water wells in the map area that can optionally be plotted on the map
    DATABASE STRUCTURE - ARC/INFO ====================================
    The database of the map consists of four coverages (root name Mesquite) and four additional info files. There are also four parallel coverages (rootname mesqexpl) that make up an explanation sheet with a correlation of map units diagram, list of map unit symbols and names, and an explanation of symbols.
    Mesquitepoly coverage: Contains all contact lines and labelpoints for each polygon. The CODE item defines the significance of the lines as listed above and in the gsmcode.lut INFO file. The P1 item defines the category of polygon as listed above and in the gsmunit.lut INFO file.
    Mesquiteline coverage: Contains faults, fold axis, and other non-contact lines. Faults that are contacts also appear in the Mesquitepoly coverage. The CODE item defines the significance of the lines as listed above and in the gsmcode.lut INFO file.
    Mesquitesym coverage: Contains points recording observations, such as strike and dip of bedding, points for posting of dip or plunge values associated with the observation points, and arcs that draw out the symbols associated with the observation points and the symbols used to decorate certain lines. The CODE item defines the type of observation as listed above and in the gsmcode.lut INFO file. For rotational observations (CODE 200 to 299) the P1 item is the azimuth (strike) and the P2 item is the inclination (dip). The item gsmentity contains a unique number for each observation that ties together the observation point, posting point, and arcs that represent a single observation. That number is negative for the posting point to distinguish it from the observation point.
    Mesquitetext coverage: Contains text points that define the position, rotation, and size of text to appear on the face of the map. Also includes arcs that draw leaders from the text to the appropriate polygons. This coverage is for cartographic purposes and does not include data critical to the database information. The P1 item defines rotation of the text, the P2 item the size of text, and the TEXT item the actual text.
    Gsmrelate INFO file: Contains the information that relates the gsmcode.lut and gsmunit.lut to the pat and aat INFO files of the coverages
    Gsmunit.lut INFO file: Contains the first two columns of the table above that lists the number (P1 item) assigned to each category of polygon and the corresponding text symbol used in the map explanation and on the face of the map. The database can be made more useful by expanding this file to include items listing characteristics, age, etc. of each geologic unit, and that should be done before a final version is released.
    Gsmcode.lut INFO file: Contains a text definition of the meaning of the number stored in the CODE item of every entity in all the coverages. INFO file: Assigns a color from shadeset CTR269.shd for each category of polygon according to the P1 item.
    Auxiliary files:
    Gsmdraw.aml and gsmdraw.mnu files are included to constitute an ARC/INFO macro language program that will extract information from the Mesquite coverages to produce a graphics (.gra) file depicting the Mesquite geologic map. The graphics file can be viewed on screen or plotted with appropriate equipment.
    The aml program calls shadeset ctr269.shd, font font003, and lineset alcwrg.lin, so these are also included in the archive file. Other files can be substituted, but special geologic characters may not plot properly with a different font.

    Database root name: MESQUITE
    1,Qfp, Flood-plain alluvium
    2,Qrm, Recent mainstream alluvium
    3,Qim, Intermediate-age mainstream alluvium
    4,Qom, Old mainstream alluvium
    5,Trm, Tertiary mainstream alluvium
    6,Trs, Tertiary sidestream alluvium
    10,Qs, Channel alluvium
    35,Qiz, Intermediate-age mainstream alluvium, sand and silt facies
    46,af, Artificial fill and other land disturbance
    47,Tms, Muddy Creek Formation
    48,Tmc, Muddy Creek Formation conglomerate facies
    53,Qis, Intermediate-age sidestream alluvium
    54,Trs, Tertiary sidestream alluvium
    56,Qos, Old sidestream alluvium
    148,Trs, Tertiary sidestream alluvium (pediment on Muddy Creek Formation)
    150,Qos, Old side-stream alluvium (pediment on Muddy Creek Formation)
    152,Tok, Old Tertiary calcrete
    153,Qe, Windblown sand
    161,Qc, Colluvium
    167,Ql, Landslide deposits
    173,Qrs, Recent sidestream alluvium
    177,Qym, Young mainstream alluvium
    179,Qys, Young sidestream alluvium
    193,Qok, Old Pleistocene calcrete
    200,Tik, Intermediate-age Tertiary calcrete
    201,Trk, Young Tertiary calcrete
    218,Tb, Tertiary basalt lava flow and ash
    219,Tf, Post-Muddy Creek Tertiary basin-fill sediments
    FEATURES IN THE DATABASE-------------------------
    001  | Geologic contacts
    008  | Normal fault -certain
    009  | Normal fault - approximately located
    010  | Normal fault - concealed
    011  | Basaltic ash marker bed line
    020  | Fold axis lines
    054  | Roads
    061  | Map boundary
    197  | Field observation point symbol
    201  | bedding dip symbol
    204  | anticline symbol
    205  | syncline symbol
    207  | ball & bar symbol
    208  | fault dip symbol
    255  | monocline - anticline symbol
    256  | monocline - syncline symbol
    313  | gravel pit symbol
    375  | water well symbol
    501  | geologic unit tag point
    555  | geologic unit tag point and text label
    599  | Map margin text

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Van S. Williams
  2. Who also contributed to the data set?
    Cooperating agencies: Southern Nevada Water Authority and Virgin Valley Water District
  3. To whom should users address questions about the data?

Why was the data set created?

Provides geologic data to support the rapid development and population growth around the town of Mesquite, particularly the siting of municipal water supply wells

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 1996 (process 1 of 2)
    Geology mapped in 1995 and 1996. Compilation completed 9/96. Review and revision completed 10/96. Archive files prepared 2/97.
    The Mesquite geologic database was compiled using the GSMCAD public domain program (USGS Open-File Report 96-007). It was exported to ARC/INFO using the GSMCAD export function to create ARC generate ASCII files and the gsmarc.aml program in ARC to convert the ASCII files to ARC coverages and build polygons. The gsmdraw.aml program was used in ARC to produce a graphics file of the colored map. In addition an explanation sheet was produced that includes a correlation of map units diagram, a list of map unit names and corresponding symbols, and an explanation of graphical map symbols.
    Date: 23-Mar-2010 (process 2 of 2)
    Creation of original metadata record Person who carried out this activity:
    Van S. Williams
    U.S. Geological Survey, National Cooperative Geologic Mapping Team
    MS 913, Box 25046 DFC
    Lakewood, CO

    (303) 236-1289 office (voice)
  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?
    Data was entered and checked by the geologist who made the observations.
  2. How accurate are the geographic locations?
    Lines were primarily positioned by photointerpretation of aerial photographs using a PG-2 photogrammetric plotter that rectified the position and transferred it to a basemap. Lines were digitized from the basemap using a digitizer tablet with resolution of 0.001 inch. Additional lines and point observations were added in the field using positions determined by a PLGR-95 GPS unit with accuracy of about 10 meters. Most positions on the map are estimated to be accurate closer than 30 m horizontally. There is no elevation data in the database.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the observations, including topology?
    Map elements were visually checked by the author for overshoots, undershoots, duplicate features, and other errors. The report is preliminary and has not been thoroughly reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. The map was reviewed by another geologist for consistency with basic geologic principles and general conformity to USGS mapping standards.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
none. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey, National Cooperative Geologic Mapping Team
    MS 913, Box 25046 DFC
    Lakewood, CO

    (303) 236-1289 office (voice)
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Although this digital spatial data has been subjected to rigorous review and is substantially complete, it is released on the condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.
    This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards and stratigraphic nomenclature. Data is complete: no features were eliminated or generalized. There is no cross section and the ARC/INFO database lacks a unit properties table, although unit properties are described in the text explanation. A base map coverage is not included but is available separately.
  4. How can I download or order the data?

Who wrote the metadata?

Last modified: 05-Feb-2016
Last Reviewed: 26-Sep-2003
Metadata author:
Peter N Schweitzer
USGS Midwest Area
Collection manager, USGS Geoscience Data Clearinghouse,
Mail Stop 954
12201 Sunrise Valley Dr
Reston, VA

703-648-6533 (voice)
703-648-6252 (FAX)
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <>
Generated by mp version 2.9.48 on Tue Jul 03 20:06:44 2018