Federal Geographic Data Committee

Geologic Data Subcommittee

PROJECT TITLE: FGDC Standard for Geologic Map Symbolization

DATE OF PROPOSAL: April 18, revised on July 14, 1997

TYPE OF STANDARD PROPOSED: Data Symbology

SUBMITTING ORGANIZATION: FGDC Geologic Data Subcommittee

POINT OF CONTACT: David R. Soller, USGS

OBJECTIVES: The objective is to provide a national standard for geologic map symbols, colors, and patterns in order to provide geologic map products that have a standard appearance.

SCOPE: The scope of this project covers cartographic symbols and patterns that are on geologic maps. The scope includes colors that are used to convey areas of particular formation, age, or lithology.

JUSTIFICATION/BENEFITS: Geologic maps are produced by various State and Federal agencies, according to various locally-developed guidelines for content and form. National or regional standards for symbolizing geologic map elements do not exist. Locally developed standards or guidelines used by a geologic mapping agency have not been widely adopted. A national standard is needed to provide a standard cartographic product to the end-user. Because most new maps are produced from digital files, this standard must be robust enough to be implemented in digital form on a variety of hardcopy output devices.

DEVELOPMENT APPROACH: This standard will be based on symbolization contained in USGS Open-file Report 95-525 "(draft) Cartographic and digital standard for geologic map information." The approach will be as follows:

• Conduct a review of USGS OFR95-525 to determine elements of the document that should be further developed as a FGDC draft standard (this review was released as USGS Open-file Report 96-725 and is available on-line at http://ngmdb.usgs.gov/Info/standards/carto/OFR95-525review.html).
• The review concluded that the symbols, colors, and patterns in the document should be converted to digital form for consideration as a FGDC standard and for general use within the USGS. This conversion is underway within the USGS.
• The digital symbols will form the basis of a draft standards document to be prepared by the Geologic Data Subcommittee late in 1997.
• The document will then be submitted to FGDC for review.

RELATED STANDARDS: The proposed standard will be based on symbolization contained in USGS Open-file Report 95-525 "(draft) Cartographic and digital standard for geologic map information." Potential relation to ISO Standard 710, 1974, Parts 1-7 will be evaluated.

DEVELOPMENT AND COMPLETION SCHEDULE:

• In late summer, 1997, the USGS will finish a first draft of the digital symbols to be contained in the standard.
• The Geologic Data Subcommittee will evaluate those symbols, and in late 1997, the Geologic Data Subcommittee will begin compiling the digital symbols into a draft FGDC standards document.
• In the first quarter of 1998, the document will be submitted to FGDC for review.

RESOURCES REQUIRED: The USGS is supporting development of the standards document and the implementation.

POTENTIAL PARTICIPANTS: The USGS, the Association of American State Geologists, the Geologic Data Subcommittee, professional societies, and private companies.

OTHER TARGETED AUTHORIZATION BODIES: None.