Geology and Resource Assessment of the Venezuelan ... - USGS

PROJECT OVERVIEW
Conversion of the Venezuela maps to a computerized digital format was
undertaken for the following reasons:
1) The digital format facilitates the presentation and analysis of earth-science data.
Digital maps can be displayed at any scale or projection, whereas a paper map has a
fixed scale and projection. However, the maps on this disc are not intended to be used
at any scale more detailed than 1:500,000.
A geographic information system (GIS) allows combining and overlaying of
layers for analysis of spatial relations not readily apparent in the standard paper
publication. Digital data on geology, geophysics, and geochemistry can be combined
to create useful derivative products.
2) The digital format was used to facilitate publication in both paper and electronic
form. For the Río Caura paper map publication (Brooks and others, 1995), digital
images were sent to the Gerber plotter, a vector-to-film processor. The other
1:500,000-scale MF maps were reproduced photographically from electrostatic plotter
output on clear mylar. The published digital formats include this CD-ROM and
ARC/INFO Export files to be located on the World Wide Web on the Internet.