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Geology of National Parks, 3D and Photographic Tours

Pinnacles National Monument
The volcanic rocks of The Pinnacles are riddled with vertical joints (fractures in the bedrock). The surfaces of the joints are exposed to water and air, both of which enhance chemical weathering. Weathered bedrock is more susceptible to erosion than unweathered rock. In this landscape, the result has been the formation of spires and pinnacles of spheroidally weathered rock.
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