Upheaval Dome is an enigmatic geological structure in San Juan County, Utah, United States, that has been variously interpreted as a meteorite impact structure or a salt dome. The structure lies southwest of the city of Moab, Utah, in the Island in the Sky section of Canyonlands National Park.

Description

thumb| Aerial [[orthophoto, 2011. Note scale at lower right.]]

Upheaval Dome is around in diameter and the crater is known to be less than 170 million years old (Jurassic or younger, but how much younger is not established.) The crater is clearly visible on the surface as light and dark brown concentric rings.

Stratigraphically, the oldest formation exposed in the center of the dome is the Permian Organ Rock Shale. This is overlain by the Permian White Rim Sandstone. Both are sometimes considered part of the Cutler Formation. Overlying these are the Triassic Moenkopi Formation (which is bounded top and bottom by unconformities), the Chinle Formation, the cliff-forming Wingate Sandstone, the Kayenta Formation, and the crossbedded Triassic-Jurassic Navajo Sandstone.

Structurally, the dome is anomalous. Most of the rock strata of Canyonlands National Park are flat-lying or gently dipping with the exception of a series of linear salt walls and associated synclines. Upheaval Dome is a circular, dome-shaped structure. Some strata near the center are nearly vertical in orientation. Dips of 70 degrees have been measured in the Kayenta Formation on the U-shaped plateau surrounding the center of the structure. A syncline surrounds the center, where the axis forms a complete circle approximately two miles across. The syncline is primarily visible in the Navajo Sandstone. Another anticline has been mapped to the north of this ring syncline, which is also concentric with it. In 2008, it was announced that shocked quartz was discovered in addition to the numerous impact-related features described by Kriens et al. in 1998.

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Image:Upheaval_Dome_air.jpg|Oblique air photo facing southeast from around 30,000&nbsp;feet

Image:Upheaval Dome.jpg|Upheaval Dome as seen from the rim of the structure

Image:Upheaval_Syncline_campsite.jpg|Syncline in Navajo Sandstone visible from the Syncline Campsite on the northwest side of the structure, facing south

Image:Upheaval_center.jpg|Steeply dipping rock strata near the center of the dome

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References

  • Upheaval dome on PASSC Earth Impact Database
  • U.S. Dept. of the Interior, National Park Service Upheaval Dome
  • Shocked Quartz discovery
  • Aerial Exploration of the Upheaval Dome impact crater