Geologic Provinces of the United States: Records of an Active Earth
Digital shaded relief map of the United States. Click here to enlarge.
Records of an active Earth
The richly textured landscape of the United States is a product of the dueling forces of plate tectonics, weathering and erosion. Over the 4.5 billion-year history of our Earth, tectonic upheavals and colliding plates have raised great mountain ranges while the forces of erosion and weathering worked to tear them down. Even after many millions of years, records of Earth's great upheavals remain imprinted as textural variations and surface patterns that define distinctive landscapes or provinces.
The diversity of our nation's landscapes can be easily seen on the shaded relief image to the left. The stark contrast between the rough' texture of the western US and the smooth' central and eastern regions is immediately apparent. Differences in roughness (topographic relief) result from a variety of processes acting on the underlying rock. As you might guess, the plate tectonic history of a region strongly influences the rock type and structure exposed at the surface, but differing rates of erosion that accompany changing climates can also have profound impacts on the land. If you spend a moment observing the map above you will probably be able to distinguish the boundaries between several geologic provinces (Click here to test your observational skills).
Each province has its own fascinating geologic history and unique features. Our National Parks preserve some of the most scenic elements of our country's rich geological heritage. Click on either the map below or the links at the bottom of the page to explore each region. There will also be a link to lists of National Parks showcasing each geologic province's geology.