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


U.S. Geological Survey

Cooperating agencies: Southern Nevada Water Authority and Virgin Valley Water District

Author or compiler: Van S. Williams

Publication_Date: 1996

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

Series_Name: Open-File Report
Issue_Identification: 96-0676

Publication_Place: Denver, Colorado

Publisher: U.S. Geological Survey


Abstract: 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.

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

Map political location: Clark and Lincoln counties, Nevada and Mohave county, Arizona Compilation scale: 1:24000 Geology mapped in 1995 and 1996. Compilation completed 9/96. Review and revision completed 10/96. Archive files prepared 2/97.

Calendar_Date: 19961024

Currentness_Reference: publication date

Progress: Complete

Maintenance_and_Update_Frequency: Irregular. Mapping is continuing in adjacent areas and a more complete final map of this area may eventually be produced. Lacks a cross section.

West_Bounding_Coordinate: -114.125
East_Bounding_Coordinate: -114.0
North_Bounding_Coordinate: 36.875
South_Bounding_Coordinate: 36.750

Theme_Keyword_Thesaurus: Geology
Theme_Keyword: Geologic map
Theme_Keyword: Stratigraphy
Theme_Keyword: Quaternary alluvium

Theme_Keyword: Tertiary basin-fill sedimentary rocks
Theme_Keyword: Tertiary volcanic rocks
Theme_Keyword: Normal faults

Place_Keyword_Thesaurus: none
Place_Keyword: Nevada
Place_Keyword: Arizona
Place_Keyword: Mohave County, Arizona
Place_Keyword: Clark County, Nevada
Lincoln County, Nevada

Access_Constraints: none

none. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data.

Attribute_Accuracy_Report: Data was entered and checked by the geologist who made the observations.


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.


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.


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.


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.

Process_Date: 1996

Direct_Spatial_Reference_Method: Vector

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_Coordinate_Encoding_Method: coordinate pair
Abscissa_Resolution: 0.001
Ordinate_Resolution: 0.001
Planar_Distance_Units: METERS

Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.98


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

Contact_Organization: U.S. Geological Survey, National Cooperative Geologic Mapping Team

Address_Type: mailing address
Address: U.S. Geological Survey
Address: MS 913, Box 25046 DFC
City: Lakewood
State_or_Province: CO
Postal_Code: 80225-0046
Contact_Voice_Telephone: (303) 236-1289 office
Contact_Voice_Telephone: (303) 236-7880 secretary

Distribution_Liability: 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.

Format_Name: GSMCAD
Format_Version_Number: all
Format_Version_Date: 1993
File_Decompression_Technique: PKZIP self-extracting archive, MS-DOS or Windows
Fees: none

Metadata_Date: 19970218
Metadata_Review_Date: 19970219
Contact_Person: Van S. Williams
Contact_Organization: U.S. Geological Survey, National Cooperative Geologic Mapping Team

Address_Type: mailing address
Address: U.S. Geological Survey
Address: MS 913, Box 25046 DFC
City: Lakewood
State_or_Province: CO
Postal_Code: 80225-0046
Contact_Voice_Telephone: (303) 236-1289 office
Contact_Voice_Telephone: (303) 236-7880 secretary

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: 19940608

Generated by mp on Thu Feb 27 14:51:30 1997