Geology of the Conterminous United States at 1:2,500,000 Scale -- A Digital Representation of the 1974 P.B. King and H.M. Beikman Map

Conversion of the geologic map of the U.S. to a digital format was undertaken
to facilitate 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 geology on this disc is not intended
to be used at any scale finer than 1:2,500,000.

This CD-ROM contains a digital version of the Geologic Map of the United
States, originally published at a scale of 1:2,500,000 (King and Beikman,
1974b). It excludes Alaska and Hawaii. In addition to the graphical formats,
the map key is included in ASCII text.

A geographic information system (GIS) allows combining and overlaying of layers
for analysis of spatial relations not readily apparent in the standard paper
publication. This disc contains only geology. However, digital data on
geology, geophysics, and geochemistry can be combined to create useful
derivative products-- for example, see Phillips and others (1993).

This CD-ROM contains a copy of the text and figures from Professional Paper 901
by King and Beikman (1974a). This text describes the historical background of
the map, details of the compilation process, and limitations to interpretation.
The digital version of the text can be searched for keywords or phrases.

For DOS users, the CD-ROM contains menu-driven analytical software, in which
the user selects from an array of topics. The CD-ROM also contains MAPPER
display software, a user-friendly package that displays the interactive vector
map. The raster image of the geologic map can be displayed with VIEWLBL.

For other types of computer users, the map must be converted from one of the
following formats included on the CD-ROM:

ARC/INFO 6.1.1 Export
Digital Line Graph (DLG) Optional
Drawing Exchange File (DXF)
Map Overlay Statistical System (MOSS)