The Geologic Data Subcommittee (GDS) of the Federal Geographic Data Committee (FGDC) is responsible for coordination of geologic data-related activities

FGDC Digital Cartographic Standard for
Geologic Map Symbolization

Questions, comments, suggestions?
Please contact Dave Soller and Taryn Lindquist.

What is this Standard?

The Federal Geographic Data Committee (FGDC) has endorsed this document as the National Standard for the digital cartographic representation of geologic map features. The standard is intended to support the Nation's producers and users of geologic map information by providing line symbols, point symbols, and colors and patterns that can be used to portray the various features on geologic maps. The objective is to aid in the production of geologic maps and related products, as well as to help provide geologic maps and products that are more consistent in both their appearance and their underlying database content.

The standard contains descriptions, examples, cartographic specifications, and notes on usage for a wide variety of symbols that may be used on typical, general-purpose geologic maps and related products such as cross sections. However, the standard also can be used for different kinds of special-purpose or derivative map products and databases that may be focused on a specific geoscience topic (for example, slope stability) or class of features (for example, a fault map). The standard is scale-independent, meaning that the symbols are appropriate for use with geologic mapping compiled or published at any scale. It is designed to be useful to anyone who either produces or uses geologic map information, whether in analog or digital form.

Who should use it?

This standard is applicable to all geologic map information (in other words, geologic maps and databases) published by the Federal Government and its Federally funded contractors and collaborators. Non-Federal agencies and private firms that produce geologic map information also are urged to adopt the standard. The standard applies to all forms of geologic map publications, whether they are released as (1) hard-copy products, in either offset-print or plot-on-demand format, or (2) digital products, either as files for spatial analysis in Geographic Information Systems (GIS), as Portable Document Format (PDF) files in online publications, or as browse-graphic files for display on the World Wide Web. In particular, the standard applies to all geologic map products archived within the National Geologic Map Database (NGMDB), which is administered by the USGS: geologic map products submitted to and incorporated within the NGMDB will conform to this standard.