Aerial view of Upheaval Dome from the south. It is marked by a 500
m-deep, 1500 m-wide central depression of soft, deformed rocks eroded down
by a tributary of the Green River.
Part of the central depression of Upheaval Dome, viewed from the north
rim. The greenish rocks are highly deformed Moenkopi Formation, having
a unique coloring and uplifted more than 500 m stratigraphically.
Park Service plaque at the Upheaval Dome overlook explaining the salt
dome hypothesis for its origin.
This attached-dome hypothesis would produce only extension in the overlying
rocks. A piercement-dome hypothesis has been proposed, requiring radial
compression after the detached salt diapir has risen to the surface and
eroded away. However, no one has ever found the slightest scrap of salt
or any part of the Paradox formation in the Dome's center.
Example of a piercement salt dome (D) in a seismic reflection section,
including a ring syncline (R) from slumping into escaped salt. Note that
the stratigraphic uplift, driven from below, must be less than the uplift
of the salt. In a salt dome, deformation increases with depth.
Park Service plaque at the overlook giving an impact hypothesis. Erosion
of the central depression must have followed impact, so Upheaval Dome would
expose the roots of impact deformation.
The Lunar crater Alfrancus represents a simple impact blast excavation.
Tycho is a larger, more complex crater that was modified by radially-inward
detachment and slumping of the walls of the transient cavity excavated
by the impact. The radial compression raises a central peak.
Topography of a formation below the crater Mjolnir in the Barents Sea,
from a 3-d seismic reflection survey. Radial slump blocks create a central
uplift, leaving an extended ring syncline.
Map of Upheaval Dome and the surrounding mesas and canyons, with the
4 km-radius ring syncline shaded in purple, refraction source points (yellow
stars), refraction recorders (blue triangles), and the reflection survey
route shaded in blue-green. The well in the ring syncline is complemented
by a well a few kilometers off the map to the southwest at Willow Flat.
Aerial view NW from the west end of Buck Mesa toward the Green River,
showing the extreme topography.
Radial-axis folds at the base of the Wingate exposed on the north edge
of the central depression.
These ``napkin-ring'' folds evidence the radially-inward compression
that created the central peak uplift.
Note that, in the impact hypothesis, driven from above, deformation
should decrease with depth.
