Upheaval Dome is a circular geological structure located in the San Rafael Swell of south‑central Utah, United States. It lies within the boundaries of Canyonlands National Park, near the junction of the Green River and the Colorado River. The feature measures approximately 5 kilometres (3 mi) in diameter and is up to 300 metres (1,000 ft) deep.
Geological description
The dome consists of steeply‑dip‑ingrafted sedimentary rocks ranging from Cambrian to Jurassic age that have been uplifted and deformed in a roughly concentric pattern. The surrounding region is characterized by the Chinle Formation, Morrison Formation, and other units typical of the Colorado Plateau. The exposed strata display a pattern of folding, faulting, and brecciation that is not typical of the surrounding plateau topography.
Interpretations of origin
Two principal hypotheses have been proposed to explain the origin of Upheaval Dome:
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Impact hypothesis – Some geologists argue that the dome is an eroded impact crater formed by the collision of a meteorite with the Earth's surface during the late Cretaceous to early Paleogene period. Supporting evidence cited includes shatter cones, shocked quartz, and high‑pressure mineral phases identified in drill cores and surface samples.
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Salt‑dome hypothesis – An alternative interpretation attributes the uplift to the diapiric ascent of a deep salt layer (gypsum or halite) that forced the overlying sedimentary rocks upward, creating a dome‑like structure. This model emphasizes the regional presence of evaporite deposits and the lack of definitive impact markers in some sections of the dome.
Both hypotheses remain subject to ongoing research, and the scientific community has not reached a consensus on a single definitive origin.
Discovery and study
Upheaval Dome was first noted by early 20th‑century explorers and later mapped in detail by the United States Geological Survey (USGS). In the 1970s, a drill core project conducted by the USGS and the University of Utah retrieved subsurface samples that have been central to the impact versus salt‑dome debate. Subsequent field investigations, remote‑sensing analyses, and geophysical surveys have continued to refine the understanding of the structure.
Significance
The feature is of interest to geologists, planetary scientists, and planetary impact specialists because it presents a well‑preserved example of a large, deeply eroded structure whose origin can illuminate processes of impact cratering, diapirism, and landscape evolution on Earth. Its location within a protected national park also makes it accessible for educational and interpretive activities.
Conservation
As part of Canyonlands National Park, Upheaval Dome is protected under federal law, and any scientific field work requires permits and compliance with park regulations to preserve the integrity of the site.
