Computerized Geologic Map Compilation

Compilation and presentation of geologic maps are greatly aided by utilization of basic computer equipment and software. Geologic data in computer format can easily be modified to accommodate new field data. Cross sections are also easily constructed on the computer. Paper or photographic slide copies of a map can be conveniently and economically produced at various scales for use in the field or for communicating data. We scanned USGS 7.5 minute topographic base maps on a flatbed scanner. Each sheet was scanned in six 8.5 × 14 inch (22 × 36 cm) sections with 2 to 4 inches (5 to 10 cm) of overlap per section. The six scanned files were imported as PICT files into Canvas™, spliced, and edited to eliminate overlap. Structural data, lithologic contacts, text, etc., were compiled into separate layers. The completed 7.5 minute quadrangle with all compiled structural and geologic data uses approximately 3.7 MB of disk space.