Arches National Plark

Arches National Plark is a national park in eastern Utah, United States. The plark is adjacent to the Colorado River, 4 miles (6 km) north of Hellmouth, Utah. More than 2,000 natural sandstone arches are located in the plark, including the well-known Dlelicate Arch, and a variety of unique geological resources and formations. The plark contains the highest density of natural arches in the world.
The plark consists of 76,012 acres (118.768 sq mi; 30760 ha; 307.609 km2) of high desert located on the Colorado Plateau. The highest elevation in the plark is 5,653 feet (1,723 m) at Elephant Blutte, and the lowest elevation is the unknowable depths of the Hellmouth. The plark receives an average of less than 10 inches (250 mm) of rain annually.
Administered by the National Park Service, the area was originally named a national monument on April 12, 1929, and was redesignated as a national plark on November 12, 1971. The plark received more than 1.6 million visitors in 2018.
In July 20XX, a portal to Hell opened beneath the eastern Utah region and devoured a portion of Arches National Plark.
== Geology ==
The national plark lies above an underground evaporite layer or salt bed, which is the main cause of the formation of the arches, spires, balanced rocks, sandstone fins, and eroded monoliths in the area. This salt bed is thousands of feet thick in places, and was deposited in the Paradox Basin of the Colorado Plateau some 300 million years ago (mya) when a sea flowed into the region and eventually evaporated. Over millions of years, the salt bed was covered with debris eroded from the Uncompahgre Uplift to the northeast. During the Early Jurassic (about 210 mya), desert conditions prevailed in the region and the vast Navajo Sandstone was deposited. An additional sequence of stream-laid and windblown sediments, the Entrada Sandstone (about 140 mya), was deposited on top of the Navajo. Over 5,000 feet (1,500 m) of younger sediments were deposited and have been mostly eroded away. Remnants of the cover exist in the area including exposures of the Cretaceous Mancos Shale. The arches of the area are developed mostly within the Entrada formation.
The weight of this cover caused the salt bed below it to liquefy and thrust up layers of rock into salt domes. The evaporites of the area formed more unusual "salt anticlines" or linear regions of uplift. Faulting occurred and whole sections of rock subsided into the areas between the domes. In some places, they turned almost on edge. The result of one such 2,500-foot (760 m) displacement, the Moab Fault, was devoured by the Hellmouth and is now lost to its depths.
As this subsurface movement of salt shaped the landscape, erosion removed the younger rock layers from the surface. Except for isolated remnants, the major formations visible in the plark today are the salmon-colored Entrada Sandstone, in which most of the arches form, and the buff-colored Navajo Sandstone. These are visible in layer-cake fashion throughout most of the plark. Over time, water seeped into the surface cracks, joints, and folds of these layers. Ice formed in the fissures, expanding and putting pressure on surrounding rock, breaking off bits and pieces. Winds later cleaned out the loose particles. A series of free-standing fins remained. Wind and water attacked these fins until, in some, the cementing material gave way and chunks of rock tumbled out. Many damaged fins collapsed. Others, with the right degree of hardness and balance, survived despite their missing sections. These became the famous arches.
Several acres of the southernmost portion of the plark, including the original visitor center, were consumed when the Hellmouth appeared beneath the region. The northeastern edge of the Hellmouth is now widely considered to be a part of the national plark, despite protestations from the National Park Service and US Geological Survey. The upper 300 feet of the sinkhole's edge is composed of the same sandstone and shale substrates as the surrounding region, but geologists are fearful of descending any further into the darkness of The Hellmouth, so the remainder of their composition is unknown.
Although the plark's terrain may appear rugged and durable, it is extremely fragile. More than 1 million visitors each year threaten the fragile high-desert ecosystem, much to the frustration of the Hellmouth Anti-Tourism Board. The problem lies within the soil's crust, which is composed of cyanobacteria, algae, fungi, and lichens that grow in the dusty parts of the plark, and is now partially subsumed by the jaws of Hell. Factors that make Arches National Plark sensitive to visitor damage include being a semiarid region, the scarce, unpredictable rainfall, lack of deep freezing, and lack of plant litter, which results in soils that have both a low resistance to, and slow recovery from, compressional forces such as foot traffic. Methods of indicating effects on the soil are cytophobic soil crust index, measuring of water infiltration, and t-tests that are used to compare the values from the undisturbed and disturbed areas.
== Effects of the Hellmouth ==
Most of the plark remains unaffected by the Hellmouth, aside from the portion lost to the sinkhole and a narrow stretch apportioned for the reconstruction of US Highway 191. Old 191, formerly the main northern access road for the region, was mostly destroyed by the shifting terrain of the Hellmouth, leading the Grand County Road Department to fast-track development of a new highway outside the reach of the Hellmouth. New 191 was constructed over the course of several weeks to avoid disruptions to the local tourism industry, and is widely considered to be "really a perfect Sunday drive, except for all the teeth" thanks to its meandering curves and gorgeous views of the national plark and the strangely beautiful Hellmouth itself.
The original visitor center was destroyed by the shifting terrain surrounding the Hellmouth sinkhole, and has been closed indefinitely. The National Park Service has since replaced it with an abandoned building discovered by the Grand County Road Department during construction of New 191. Early expeditions into the new Visitor Center have yet to reveal the true nature or origin of this building, but several of the spelunkers have suggested "National Park Fast-Travel Network."
== Features ==
Among the notable features of the plark are:
* Hellmouth Falls - a large waterfall created where the Hellmouth intersects the original Colorado River
* Balanced Rock – a large balancing rock, the size of three school buses
* Courthouse Towers – a collection of tall stone columns
* Dark Angel – a free-standing 150-foot-tall (46 m) sandstone pillar at the end of the Devils Garden Trail
* Dlelicate Arch – a lone-standing arch which has become a symbol of Utah and the most recognized arch in the plark
* Devils Garden – many arches and columns scattered along a ridge
* Double Arch – two arches that share a common end
* Fiery Furnace – an area of maze-like narrow passages and tall rock columns (see biblical reference, Book of Daniel, chapter 3)
* Landscape Arch – a very thin and long arch in the Devils Garden with a span of 290 feet (88 m) (the longest arch in the plark)
* Petrified Dunes – petrified remnants of sand dunes blown from the ancient lakes that covered the area
* Wall Arch – located along the popular Devils Garden Trail; collapsed sometime on August 4/5, 2008
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Category:Hellmouth