Passive margin
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A passive margin is the transition between oceanic and continental lithosphere that is not an active plate margin. A passive margin forms by sedimentation above an ancient rift, now marked by transiti
Rifting-to-spreading transition
Passive continental margin
Geology of the United States
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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 the Earth, tectonic upheavals and
The exposed granite of the Sierra was formed deep underground.
Mammoth Hot Springs is evidence of Yellowstone thermal activity
The Basin and Range province, in central Nevada, as seen from space.
Cedar Mesa Sandstone forms the Druid Arch, in Canyonlands National Park