Digital Cartographic Standard for Geologic Map Symbolization

Document number


Maintainance authority



This standard is intended to provide to the Nation's producers and users of geologic-map information a single, modern standard for the digital cartographic representation of geologic features. The objective in developing this national standard for geologic map symbols, colors, and patterns is to aid in the production of geologic maps and related products, as well as to help provide maps and products that have a consistent appearance.


The standard provides descriptions, examples, cartographic specifications, and notes on usage for a wide variety of symbols that may be used on a typical digital geologic map or related product (for example, cross sections). To the extent possible, symbols and specifications were retained from previous informal and draft standards (the USGS "Technical Cartographic Standards", ca. 1975; and USGS Open-file Report 95-525). However, the map symbols have been reorganized and the number of symbols has increased from about 800 to almost 1200. This draft standard also includes a newly revised CMYK color chart, a chart of commonly used geologic map patterns, a geologic age symbol font, and a variety of bar scales, mean declination arrows, and quadrangle location maps.


The standard is designed for use by anyone who either produces or uses digital geologic-map information. The standard applies to geologic-map information published by the Federal government in both offset-print and plot-on-demand formats. It also is suitable for use in electronic publications (for example, in a Portable Document Format (PDF) file) and for display by computer monitors. The standard is scale-independent, meaning that the symbols are appropriate for use on geologic maps at any scale. Non-Federal agencies and private companies that produce geologic-map information are urged to adopt this standard as well.

Sponsored by

FGDC Geological Data Subcommittee

Project history

Public review draft 2000-06 FGDC Secretariat
Final draft 2005-12 FGDC Standards Working Group
Final draft 2006-07 FGDC Coordination Group
FGDC-endorsed standard 2006-08 USGS