Open-File Report 96-676: README file

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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. A more complete description of the characteristics of the database is given in the metadata document (mesquite.mda). The project is the result of cooperation between the U.S. Geological Survey, the Southern Nevada Water Authority, and the Virgin Valley Water District.

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.

PC format:
The of96-676.exe file is a self extracting archive. When executed it will create a directory named mesquite and place the uncompressed and separated components of the database in that directory. The data in these files can be converted into ARC/INFO generate, DXF, and other ASCII formats by using free GSMCAD software.

File in the archive are:

This text file

Text file of the discription of map units and discussion of deposits, structure, and geologic history. Unit descriptions can be accessed by selecting map unit unit symbols displayed on screen.

Text file of the metadata document describing the Mesquite database

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

Unix format:
The Mesquite.tar.gz file is an archive compressed with the GNU utility gzip, which is available from various GNU source sites.

To uncompress the data in UNIX enter:
gunzip mesquite.tar

To separate the components enter:
tar vxf mesquite.tar

The result should be a directory named ofr96-676 containing all necessary ARC/INFO coverages and infor files for the Mesquite (map) and mesqexpl (explanation sheet) databases. Included is the AML program gsmdraw.aml that will extract data from the database to produce a graphics file (.gra) that can be viewed on the screen and converted to printable format (RTL, Postscript, HPGL2). For information on the contents of the various files review the mesquite.mda metadata document.

Printable map image files:
In addition to the data, directly printable files of the map and explanation sheet are provided for direct production of a paper copy. These files are in RTL format, the native language for several types of inkjet plotters such as the Hewlett Packard designjet series. The printer files have been combined and compressed into the file Mesqrtl.tar.gz using tar and gzip as described above. logo