In 2014-2017, this database design was extensively reviewed and test-implemented by the
U.S. Geological Survey and the State Geological Surveys. During this process, certain modifications and
clarifications were made to the now-superceded version, NCGMP09v1.1. The current version was formally
published by the USGS in September of 2020 and given a new, more pronounceable name —
"GeMS" (Geologic Map Schema). Questions or comments may be directed here.
Documentation and Tools
Documentation
GeMS Toolbox
Resources
Delivery
Symbology
Standard
ArcGIS styles
-
ArcGIS Pro style
implementation of FGDC Standard — Comprehensive and authoritative implementation of the
standard created by the South Carolina Geological Survey for the NGMDB.
-
AK GeMS symbology — ArcMap style file and report
from the Alaska Division of Geological & Geopysical Surveys. Contains the majority of symbols in the
standard.
Fonts (required for style files)
-
FGDCGeoAge.otf — OpenType version of special
geologic age characters.
-
FGDCGeoSym — five TrueType font files
of geologic marker symbols used for decorating line symbols and symbolizing points. These are
required for the style files above.
Example databases
GeoMaterials vocabulary
-
GeoMaterials — terms and definitions from
Appendix 1 of the GeMS documentation, in spreadsheet form.
Miscellaneous
-
Guidance on datums — what
datum(s) should be used for our geologic map GIS databases?
-
AK GeMS Data Dictionary — a description of the
Alaska geologic mapping schema. Alaska Division of Geological & Geophysical Surveys.
-
AZGS Geomapmaker — GitHub repository for an ArcGIS
Pro ribbon tab/toolbar to help create GeMS-compliant data during the digitization process. Arizona
State Geological Survey.
-
MapMerger — GitHub repository for a tool for
merging GeMS map databases. Ryan Crow, USGS.
-
Monthly Collaborative Database Effort for Geology (CDEFG)
meetings on the development of a multi-map, multi-user database based on GeMS at the Alaska
Division of Geological and Geophysical Surveys. Many general GeMS topics discussed in addition to
building an enterprise database.
-
Workflows, tools, and documentation for working with GeMS
databases by the Wisconsin Geological & Natural History Survey.
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FGDCcmyk — ArcMap and ArcGIS Pro style files
containing only the polygon fill colors shown in the FGDC CMYK Color Chart. Also known as
wpgcmyk.style and derived from the ArcINFO shadeset wpgcmyk.shd.
-
FGDC_GSC_20100414 — ArcMap and ArcGIS Pro style files of the
Canadian Geological Survey's partial implementation of FGDC symbols; mostly point, line, and text
symbols. Requires installation of the FGDCGeoSym font files described above.
-
GSC_FGDC_GeologicMapSymbols — ArcMap and ArcGIS Pro style files containing both FGDCcymk and FGDC_GSC_20100414 symbols. Requires installation
of the FGDCGeoSym font files described above.
Get help
Collaborate
-
If your project or agency has tools, workflows, or documentation you would like to share, please
consider having links posted here. Write to gems@usgs.gov to
discuss.
-
Development of the python scripts in the geoprocessing toolboxes is handled through GitHub. If you
would like to offer changes or enhancements, the best way is through the GitHub flow but you can also send files and/or documentation for the tools and they will be
considered for incorporation.
-
If you find a bug in a toolbox tool or would like to request an enhancement, please submit an issue
at the appropriate repository (see Documentation and Tools).
-
For informal discussion of all aspects of using the schema, you can join the Gitter chat room or send an email to request to join the Digital Mapping
Techniques community listserv.
Background
GeMS ("Geologic Map Schema", formerly "NCGMP09") is the standard schema for geologic map publications
funded by the U.S. Geological Survey's National Cooperative Geologic Mapping Program (NCGMP). Its design
specifies encoding the content analogous to that contained in a traditional geologic map published by
the USGS and by State Geological Surveys. Implementation in ESRI software is described in GeMS, in order
to adhere to USGS policy and because this is the GIS most commonly used in the USGS, in the State
Geological Surveys, and in the larger community.
This schema is an outcome of nearly two decades of work among numerous individuals and projects, in the
NCGMP and in other programs and in many agencies. In particular, during this period the National
Geologic Map Database project (NGMDB) has been charged under the Geologic Mapping Act to support the
development of geologic map standards and guidelines. Throughout this time, it has been clear that there
is no single "right" approach, database needs vary from project to project, and these needs may contrast
markedly with the long-term requirements for the national database. This schema, as noted, is intended
to address the needs of geologic mapping projects particularly for data delivery, and so we sought
consensus on a design that met those needs.
NCGMP09 was introduced at the Digital Mapping Techniques '09 meeting (May, 2009), as version 0.8.2, in
order to solicit preliminary comments and testing. Version 1.0 was released October 14, 2009, for
presentation at the Geological Society of America's Annual Meeting. In the months following, more
extensive evaluations were received, and in response the design evolved. A revised version was published
in the DMT'09 Proceedings as NCGMP09 (version 1.1). During that timeframe, NCGMP09 development was
supported by the USGS/AASG National Geologic Map Database Project and the USGS Pacific Northwest
Geologic Mapping Project (Ralph Haugerud, Stephen Richard, David Soller, and Evan Thoms). Since then,
implementation and potential revisions or enhancements to NCGMP09 have been conducted by a wider group
of colleagues (see Progress
Report of Sept. 25, 2013). In 2014-2017, the schema and documentation were extensively reviewed
and test-implemented by the U.S. Geological Survey and the State Geological Surveys. During this
process, the need for certain modifications and clarifications, including renaming the schema to GeMS,
was identified and in 2018, a draft of a new peer-reviewed, but still provisional, release was made
available. This was formally published on September 2, 2020 by the USGS as a Techniques and Methods
series report (number 11-B10) and is now the documentation for the current release of GeMS.
Regarding availability and maintenance of this database design, under the authority of the Geologic
Mapping Act of 1992 (and subsequent reauthorizations), the National Geologic Map Database project will
function on behalf of the NCGMP as coordinator of database design changes and maintenance. This activity
will be conducted in cooperation with NCGMP projects and other identified stakeholders (e.g., the
Association of American State Geologists). Long-terms plans include proposing GeMS as the standard
supported by the Federal
Geographic Data Committee. Please note that the schema and documentation, and the software tools
that support it will evolve over time, in response to the needs of users and geologic mappers, and to
advances in technology.
Archive of previous versions and
related information
-
Provisional release of
current version (GeMS) — superceded by USGS Techniques and Methods 11-B10 (above)
-
NCGMP09 v. 1.1 — .zip file
[4.6 MB] containing documentation, standard vocabulary, ESRI style file, and toolbox (for Arc 10.1
only)
-
NCGMP09v1_Toolbox3b.zip — Toolbox
of ArcGIS scripts for working with NCGMP09 schema
-
NCGMP09v1.1_Tools2_Arc10.1.zip
— outdated version (9/16/2103) of scripts to create and validate NCGMP09 database structure in Arc
10.1
-
NCGMP09_Toolbox_1-9-11.zip —
outdated version (1/9/2011) of scripts to create and validate NCGMP09 database structure
-
GeneralLithology_1-1.xls —
Terms, definitions, and hierarchy key
-
NCGMP09_ERdiagrams-Fig2.zip
-
NCGMP09 Migration Pilot
Project — Washington State Division of Geology and Earth Resources.
-
ESRI recommendation to Alaska DGGS, for Enterprise data model (2014; for information, contact Trish Gallagher)
-
Discrepancies noted in
NCGMP09 implementation (Arizona Geological Survey, 2014)
-
Managing multiple-attribute
lines in NCGMP09 (Ralph Haugerud, USGS, 11/18/2013)
-
Progress Report on the
evaluation and implementation of NCGMP09 (Sept. 25, 2013).
-
Geologic map
toolbar (Arizona Geological Survey)
-
Documentation of
NCGMP09 design (from DMT'09 Proceedings)
-
DMT'09 presentation (May 12, 2009;
PDF version of .ppt file)
-
DMT'09 poster (May 12, 2009; PDF
version of .ppt file)
-
NCGMP09 Version 1.1 (January
15, 2011) | Readme
-
NCGMP09 Version 1.0 (October
15, 2009) | Readme
-
NCGMP09 Version 0.8.2b (July
23, 2009; minor revisions after DMT'09) | Readme
-
NCGMP09 Version 0.8.2 (May 15,
2009; for presentation at DMT'09) | Readme
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