Geologic Map of the Grand Canyon 30' x 60' Quadrangle

Polylines and polygons USGS Geologic Investigations Series I-2688. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:100,000 or smaller.