Canyonlands is a place of relative geologic order. Layers of sedimentary deposits systematically record chapters in the park's past. With some exceptions, these layers have not been altered, tilted or folded significantly in the millions of years since they were laid down by ancient seas rivers or winds.
Upheaval Dome is quite a different story. In an area approximately three miles across, rock layers are dramatically deformed. In the center, the rocks are pushed up into a circular structure called a dome, or an anticline. Surrounding this dome is a downwarp in the rock layers called a syncline. Geologists don't know for sure what caused these folds at Upheaval Dome, two main theories are debated.
Salt Dome Theory - a thick layer of salt, formed by the evaporation of ancient seas, lies under most parts of of southeastern Utah and Canyonlands National Park. When under pressure from thousands of feet of overlying rock, the salt can flow plastically, like ice moving at the bottom of a glacier. In addition, salt is less dense than sandstone. As a result, over millions of years salt can flow up through rock layers as a "salt bubble", rising to the surface and creating salt domes that deform the surrounding rock.
Impact Crater Theory - when meteorites collide with the earth, they leave impact craters. Some geologists estimate that roughly 60 million years ago, a meteorite with a diameter of approximately one-third of a mile hit at what is now the Upheaval Dome. The impact created a large explosion, sending dust and debris high into the atmosphere. The impact initially created an unstable crater that partially collapsed. As the area around Upheaval Dome reached equilibrium, the rocks underground heaved upward to fill the void left by the impact. Erosion since the impact has washed away any meteorite debris, and now provides a glimpse into the interior of the impact crater, exposing rock layers once buried thousands of feet underground.
Directions
Starting at the Island In The Sky visitor center, follow the main road (Grand View Point Road) for about 6 miles. Then turn right and continue for another 5 miles until you reach the end of the road.
From the parking area, a short path (the Crater View Trail) climbs to the top of the rim to a viewpoint above the steepest section of the crater walls, and another branch continues half mile westwards to a second overlook, perched right on the edge of the cliffs and giving an excellent view of the crater.
