Fittingly titled, "A Tapestry of Time and Terrain," the map weaves together, in vivid colors and shadings, the topographical and geological components of the lower 48 states, as well as the geologic age of those components. This union of topographic texture with the patterns defined by units of geologic time creates a visual synthesis that has escaped most prior attempts to combine shaded relief with a second characteristic shown by color.

The colorful map is an excellent teaching tool, and comes with an interpretive booklet that explains how the map was made, and describes in brief narrative, 48 of the physical features portrayed on the map.

"A Tapestry of Time and Terrain," by Jose Vigil, Richard Pike and David Howell, is available over the counter at USGS Earth Science Information Centers in Menlo Park, Calif.; Spokane, Wash.; Denver, Colo.; and Reston, Va., for $7. It can be ordered by calling 1-888-ASK-USGS (275-8747).

The map can be previewed at tapestry.usgs.gov, which is an interactive website featuring various ways to learn more about the map and the "Rocks of Ages" depicted on it.

The geologic map used is: King, P.B., and Beikman, H.M., compilers, 1974, Geologic map of the United States (exclusive of Alaska and Hawaii): Reston, Va., U.S. Geological Survey,three sheets, scale 1:2,500,000.

The map is available online in two places:

As ARC/INFO 7 and ArcView files
In EPS format

Thanks to Joseph J. Kerski, Ph.D., Geographer - Outreach, USGS
jjkerski@usgs.gov