Geologic map and lithology patterns as defined in the FGDC Digital Cartographic Standard for Geologic Map Symbolization by the U.S. Geological Survey and the Geologic Data Subcommittee (GDS) of the Federal Geographic Data Committee (FGDC). deeptime::geo_grob() and
deeptime::geo_pattern() should be used to retrieve and modify an individual
pattern as a grob object or GridPattern
object, respectively.
Format
A list, where each item corresponds to a geologic pattern stored as a
gTree object as returned by grImport2::pictureGrob().
The names of the list correspond to the pattern codes.
Source
https://ngmdb.usgs.gov/fgdc_gds/geolsymstd.php via https://github.com/davenquinn/geologic-patterns
Details
For specific pattern codes, see the "pattern numbers" in the full pattern chart.
Daven Quinn has also assembled more accessible documentation of the map patterns/codes
and lithology patterns/codes.
rmacrostrat::def_lithologies() can also be used to look up pattern codes
for various lithologies (see the "fill" column). Note that patterns
associated with color variants (e.g., "101-M") are not included but can be
created using deeptime::geo_grob().
These patterns were originally processed and optimized by Daven Quinn and are hosted on GitHub.