Washington : Dept. of the Interior, U.S. Geological Survey : U.S. G.P.O. ; Denver, CO : For sale by the Books and Open-File Reports Section, U.S. Geological Survey, 1987.
Map displays bedrock formations at or near the surface of the land, on the sea floor above the continental crust, and oceanic crust surrounding the landmass. The bedrock units are grouped and colored acording to geological age and composition; also shows major faults and a variety of special geological features.