~ Arches National Park ~

Water and ice, extreme temperatures and underground salt movement are responsible for the sculptured rock scenery in Arches National Park. On a clear day it is difficult to imagine such violent forces or the 100 million years of erosion that created this land boasting one of the world's greatest densities of natural arches. Over 2,000 cataloged arches are in the park ranging in size from a three-foot opening to Landscape Arch measuring 306 feet from base to base. Due to the huge crowd of people in the park I did not travel out to see Landscape Arch. Remind me to not visit a national park on a holiday weekend in the future.

The geologists tell this story about Arches NP. The park lies atop an underground salt bed that is responsible for the arches, spires, balanced rocks, sandstone fins and eroded monoliths of this mecca for sightseers. In places this salt is thousands of feet thick and was deposited across the Colorado Plateau 300 million years ago, when a sea flowed into the region and, then, eventually evaporated leaving the salt behind. Over millions of years, residue from floods, winds and the oceans that developed and evaporated blanketed the salt bed. This residue was compressed into rock, which at one time may have been a mile thick. The salt bed being unstable under the weight of the rock then shifted, buckled and liquified thrusting the rock layers up as domes and entire sections fell into the cavities. Faults deep in the earth made the surface even more unstable. The Moab Fault which has a displacement of 2600 feet in some sections. More info is below with the photos.

Source: Arches National Park brochure

The Entrance

To get to the park from the Visitor Center you have to drive up that wall in the photo on the left. Both photos show the Moab Fault, which runs along the highway. Both sides of the highway were the same height long ago. When the fault shifted, the north side of the highway fell and the south side thrusted up leaving a 2600 foot difference. Of course, there was no highway when this took place 6 million years ago.

Unusual rock formations were everywhere throughout the park

Part of the Great Wall

Park Avenue

The sheer walls of this narrow canyon reminded visitors of buildings lining a big city street, hence the name Park Avenue.

What forces offset this piece of rock and what keeps it there?

In the right photo are the Three Gossips, Sheep Rock, the Tower of Babel and the Organ.

On right are Three Gossips and Sheep Rock

The Tower of Babel behind the Organ

The Tower of Babel

The dots on the right photo show what the geologists think this double arch once looked like. Like living things, arches have life cycles, too. Starting as small holes in rock faces, they enlarge and eventually collapse from weathering and erosion. At the extreme left side of the photos "Baby Arch" is forming. Although not a certainty, the sharp cleavage found on Sheep Rock and the shapes of other rock faces near it are clues that an arch once connected the "sheep" to the rock mass it faces.

A different angle on the Three Gossips

More unusual rock formations without names

The vast area in the photos above was once covered by extensive sand dunes. Some 200 million years ago, winds from the northwest carried tons of fine grained sand into this area, creating an immense desert. Over time, the sands were covered by other layers of sediment, compressed and cemented by quartz and calcite into Navajo Sandstone. Erosion has since washed away the overlying layers, exposing the "petrified" dunes.

Balanced Rock

The forces of erosion are sculpting more than arches. Balanced Rock clearly shows the various layers responsible for this amazing defiance of gravity. The caprock of hard Slick Rock of the Entrada Sandstone in perched upon a pedestal of mudstone. This softer rock weathers more quickly than the resistant rock above. Eventually, the faster-eroding rock will cause the collapse of Balanced Rock.
Throughout the park other balanced rocks, spires and pinnacles are formed as the different layers erode at different rates.
I walked the trail around Balanced Rock to take photos that show you all sides.

Salt Valley

The salts of the inland seas were buried by windblown and waterborne sediments over millions of years. The weight of the sediments forced the salt to flow, like a glacier, along its rock bed. Where the salt encountered a fault, it bulged upward forming a salt dome.
The overlying rock, unable to bend, cracked along parallel lines and pulled apart, allowing water to seep into the salt layer. The salt dissolved and leached out, leaving huge open spaces. The overelying rock, now unsupported, collapsed into the cavaties creating Salt Valley.

Delicate Arch and Wolfe Ranch

Delicate Arch is at the left
Water and time have sculpted Delicate Arch. The span's distinctive shape has inspiried such colorful nicknames as "Cowboy Chaps" and "Old Maid's Bloomers."
At present the opening in Delicate Arch is 45 feet high and 33 feet wide. Erosion continues to wear away the features of this mature span. It is only a matter of time before the geologic and environmental forces that created the arch will destroy it. Forty-three arches in the park have collapsed since 1970.

Wolfe Ranch

John Wesley Wolfe settled here in the late 1800s with his oldest son, Fred. A nagging leg injury from the Civil War prompted John to move west from Ohio, looking for a drier climate. He chose this tract of more than 100 acres along Salt Wash for its water and grassland, which would support a few cattle.
The Wolfes built a one-room cabin, a corral and a small dam across Salt Wash. For more than a decade they lived alone on the remote ranch.
When his daughter, Flora, and her husband moved to the ranch, she convinced her father to build a larger cabin with a wood floor. That is the cabin shown in the photos. The outbuilding is a root cellar. In 1910, the family returned to Ohio and John Wolfe died on October 22. 1913 at the age of eighty-four.

Looks like a bird perched up there

Something from Star Wars

Collapsing and uplifting

Another balanced rock

The Windows

The Windows Section of Arches National Park was once a national monument. It was combined with Arches National Monument to form the national park.

On the right is North Window

Elephants on Parade

Turret Arch

On the right is another view of Elephants on Parade

Sand dune cross-bending as was seen at Red Rock NCA

A major upthrust

Pothole Arch

Pothole Arch is an unusual horizontal opening in the rocks

Music is "Dream TIme"

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