Steven Dutch, Professor Emeritus, Natural and Applied Sciences, Universityof Wisconsin - Green Bay
Black Box Dolomite
Honaker Trail Formation
|Pinkerton Trail Formation|
|Above: Moab, Utah
Left: looking upstream up the Colorado River Canyon just north of Moab.
|Left and below: The highway north of Moab follows the Moab Fault. The fault is downdropped to the east; the Wingate Sandstone that makes up the cliff west of the fault is far below the surface on the east.|
|Moab Fault stratigraphy. The cliffs at the top are Wingate Sandstone (Jurassic). The somewhat greenish unit below the cliffs is the Chinle Formation. The Moenkopi is below the Chinle and thin in this area (both are Triassic), and the red beds in the foreground are the Cutler Group (Permian)|
|Nice view of the Moab Fault stratigraphy, with the cliff-forming Wingate at the top, the greenish Chinle below, with perhaps a bit of brown Moenkopi at the base, and the red Cutler group forming the bottom half of the slope.|
|Looking west on the highway to Canyonlands.|
|Another nice view of the stratigraphy, with the cliff-forming Wingate at the top, the greenish Chinle below, brown Moenkopi at the base, and the red Cutler group forming the bottom half of the slope.|
|The Merrimac (left) and Monitor (right) are two buttes north of Canyonlands, made of Entrada Sandstone, with the Carmel and Dewey Bridge Formations forming the basal slopes. The white rock below is Navajo Sandstone.|
Opposite the Visitor Center is a spectacular view. The road at the bottom and the road clinging to a ledge on the canyon rim are, amazingly, the same road.
|The Visitor Center lies just north of a narrow neck that forms the entrance to Island In The Sky, an otherwise almost inaccessible mesa. Island in the Sky is actually hard to identify on a topographic map because because there are so many deep re-entrants in the cliffs. This view, looking northwest, shows hills of Navajo Sandstone, with thin-bedded reddish Kayenta below, and the distant gorge shows cliffs of Wingate.|
|Telephoto view of the inner gorge.|
|The bluffs are Navajo Sandstone. The white color of the Navajo Sandstone is attributed to bleaching, probably by hydrocarbons. The flats below the bluffs are Kayenta with a thin veneer of Navajo in places.|
Upheaval Dome was long held to be a place where a salt dome rose, dissolved away, and the rocks collapsed into the void. It is now widely considered to be the remnant of a Jurassic impact crater. The original crater has long since been eroded away. It would have been about twice the diameter of the present structure and probably had a central peak. The present structure is the eroded remnant of the central uplift. Resistant Wingate Sandstone forms the cliffs around the structure. Dark brown Moenkopi Formation and White Rim Sandstone (Cutler Group) make up the central hills. Some geologists still prefer the collapsed salt dome interpretation.
|Distant view west from the rim of Upheaval Dome, with light Navajo Sandstone on the horizon. The Kayenta Formation underlies the vegetated bench on the far side. The lower cliffs are Wingate Sandstone with lighter Chinle Formation at the base of the talus slopes.|
|Close parallel fractures in Navajo Sandstone near the rim of Upheaval Dome, possibly related to the formation of the structure.|
|Looking west from just outside the rim, with rounded outcrops of Navajo Sandstone making up the hills.|
|Rounded light outcrops of Navajo Sandstone on the horizon. The Kayenta Formation underlies the vegetated bench on the far side and makes up the thin-bedded upper parts of the cliffs. The lower cliffs are Wingate Sandstone.|
|Views west into the canyon of the Green River.|
|Left: Inner canyon of the Green River.
Below: Desert vegetation.
|Looking east and south into the canyon of the Colorado River. The river itself is not visible.|
|The flat table land is the top of the Cutler Formation. The light sandstone unit forming the canyon edge is called, logically enough, the White Rim Sandstone Member.|
|Looking southeast over the LaSal Mountains.|
|Distant view of closely-jointed sandstone in the southern part of Canyonlands, with the La Sal Mountains beyond.|
Created 7 April 2003, Last Update 06 June 2020