A Tapestry of Time and Terrain

This stunning new map of the United States from the USGS 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. By mutually enhancing the landscape and its underlying structure, the map outlines the geologic story of continental collision and break-up, mountain-building, river erosion and deposition, glaciation, volcanism and other events and processes that have shaped the region over the past 2.6 billion years.