What does the Exploring Time and Space map portray?
The map used here was created by the US Geological Survey in Menlo Park. Through computer processing and enhancement, they wove together the topography and the geology of the United States into a single image. The new map, http://tapestry.usgs.gov/features/features.html, portrays a 3-D perspective of the land surface with the addition of the fourth dimension of geologic time, shown in color. The colors correspond to those used in the stratigraphic column representing the eras and periods of the Geological Time Scale.
