Upheaval Dome in Canyonlands National Park
by Eric Woodward and Rob Hollis
Upheaval Dome is located in South Eastern Utah, in Canyonlands National Park. It consists of a bulls eye of concentric deformed layers, dipping away from the circular anticline or dome, in the middle. The strata date from the Cambrian/Mississippian to the Mid-Jurassic. The surrounding layers in CanyonlandsNational Park are relatively flat-lying.
The mode of formation of the dome has been debated for many years. At the beginning it was proposed to be a volcano but lacking any evidence of volcanism it was rejected. Recently the idea of a salt diaper punching through flat laying strata has been suggested or that the diaper was pinched off from the stem and later eroded (Jackson and Schultz, 1998). On the other hand, studies in the last 10 mostly agree on Upheaval Dome forming due to a meteor impact (Kanbur et al., 2012, Okubo and Schultz 2007) . Recent evidence of deformation bands, seismic reflection surveys, and two stishovite grains support the theory of an impact (Kanbur et al., 2012, Okubo and Schultz 2007). Due to the rough terrain and remote location it has been difficult to gather definitive supporting data, allowing for some mystery surrounding the origin of Upheaval Dome.
A Pennsylvanian Sea was closed off by uplift of the Uncompahgre ranges and the subsidence of the Paradox Basin. The trapped body of water rapidly evaporated leaving mostly halite deposits called the Paradox Formation. During the Permian Period, the erosion of the Uncompahgre highlands deposited fine-grained clastic materials. All the while, transgressions and regressions of the Western Sea produced alternating layers of beach dune sandstones, which interfinger with the more distal fine-grained sediment eroded from highlands. This history is revealed in the three units of the Cutler Group deposited in early Permian times (Cedar Mesa, Organ Rock, and White Rim Sandstone that contain cross-stratified sandstones).
The Triassic was dominated by marine transgression, producing the formation of the Moenkopi, which consists of a fluctuating shallow marine and fluvial environment. Three divisions of the Moenkopi formation represent the facies found in each environment and are referred to as Upper, Middle and Lower Moenkopi. The Chinle Formation blanketed the uplifted terrain and deposited brightly colored shales, mudstones and siltstones. Petrified wood is also found in this unit in abundance. These sediments were deposited by river channel systems and aeolian processes. The Chinle Formation dates all the way to the latest Triassic system (Canyonlands National Park: Upheaval Dome, 2014). Early to middle Jurassic times consisted of depositing sandstones which display distinctive lithologic properties. The Wingate Sandstone represents central to back ranging erg cross-stratified facies. The Kayenta Formation represents fluvial system deposits. The Navajo is the last member deposited at the Upheaval Dome locality. The Navajo mainly consists of pure quartz cross-stratified sandstone (Jackson 1998).
To get a good idea just how large CanyonlandsNational Park is, drive to upheaval dome in the northern section of the park. Spontaneous cow crossings and sing-alongs over the radio are to be shared by all. For our trip we hiked up “Whale Rock” to get an better view of Upheaval Dome. Surprisingly enough Whale Rock actually did resemble a whale quite well. The view from the “blowhole” showed the concentric rings of different formations as well as the anticline dome in the middle. Atop the whale we discussed the various hypotheses surrounding the formation of the dome. The dome looked like a weathered formation that was hard to comprehend without an overhead view. We felt the best view of the formation would come from a bird’s eye view. You could see the anticline dome in the center quite well, and got an idea from the amount of weathering why Upheaval Dome’s origin is still being debated today.
Kanbur, Z., et al., 2012, Seismic reflection study of Upheaval Dome, Canyonlands National Park, Utah: [abs.]: Journal of Geophysical Research: Planets (1991-2012), v. 105, p. 9489-9505.
Jackson M.P.A. and Schultz-Ela D.D., 1998, Structure and Evolution of Upheaval Dome: A Pinched-Off Salt Diapir, gsabulletin.gsapubs.org pages 1547-1573
Okubo, C., and Schultz, R., 2007, Compactional deformation bands in Wingate Sandstone; additional evidence of an impact origin for Upheaval Dome, Utah: Elsevier, Earth and Planetary Science Letters, v. 256, p. 169-181.
CanyonlandsNational Park: Upheaval Dome, 2014, National Park Service: http://www.nps.gov/cany/naturescience/upheavaldome.htm