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94-600: Other formations were also formed but were mostly eroded following uplift from the Laramide orogeny which started around 70  million years ago ( Mya ). This event raised the Rocky Mountains far to the east and caused the retreat of the sea that covered the Bryce Canyon area. After Laramide mountain building came to an end, about 15 mya, a large part of western North America began to be stretched into

188-429: A glacial armor . Ice can not only erode mountains but also protect them from erosion. Depending on glacier regime, even steep alpine lands can be preserved through time with the help of ice. Scientists have proved this theory by sampling eight summits of northwestern Svalbard using Be10 and Al26, showing that northwestern Svalbard transformed from a glacier-erosion state under relatively mild glacial maxima temperature, to

282-426: A considerable depth. A gully is distinguished from a rill based on a critical cross-sectional area of at least one square foot, i.e. the size of a channel that can no longer be erased via normal tillage operations. Extreme gully erosion can progress to formation of badlands . These form under conditions of high relief on easily eroded bedrock in climates favorable to erosion. Conditions or disturbances that limit

376-408: A fall in sea level, can produce a distinctive landform called a raised beach . Chemical erosion is the loss of matter in a landscape in the form of solutes . Chemical erosion is usually calculated from the solutes found in streams. Anders Rapp pioneered the study of chemical erosion in his work about Kärkevagge published in 1960. Formation of sinkholes and other features of karst topography

470-485: A glacier-armor state occupied by cold-based, protective ice during much colder glacial maxima temperatures as the Quaternary ice age progressed. These processes, combined with erosion and transport by the water network beneath the glacier, leave behind glacial landforms such as moraines , drumlins , ground moraine (till), glaciokarst , kames, kame deltas, moulins, and glacial erratics in their wake, typically at

564-464: A homogeneous bedrock erosion pattern, curved channel cross-section beneath the ice is created. Though the glacier continues to incise vertically, the shape of the channel beneath the ice eventually remain constant, reaching a U-shaped parabolic steady-state shape as we now see in glaciated valleys . Scientists also provide a numerical estimate of the time required for the ultimate formation of a steady-shaped U-shaped valley —approximately 100,000 years. In

658-423: A large river can remove enough sediments to produce a river anticline , as isostatic rebound raises rock beds unburdened by erosion of overlying beds. Shoreline erosion, which occurs on both exposed and sheltered coasts, primarily occurs through the action of currents and waves but sea level (tidal) change can also play a role. Hydraulic action takes place when the air in a joint is suddenly compressed by

752-492: A mountain mass similar to the Himalaya into an almost-flat peneplain if there are no significant sea-level changes . Erosion of mountains massifs can create a pattern of equally high summits called summit accordance . It has been argued that extension during post-orogenic collapse is a more effective mechanism of lowering the height of orogenic mountains than erosion. Examples of heavily eroded mountain ranges include

846-402: A much slower rate, and consequently protects the weaker limestone underneath. However, the same processes that create hoodoos will also eventually destroy them. In the case of Bryce Canyon, the hoodoos' rate of erosion is 2–4 feet (0.6–1.3 m) every 100 years. As the canyon continues to erode to the west it will eventually capture (in perhaps 3 million years) the watershed of

940-592: A shortcut to the sea by flowing into the new gulf. This significantly decreased the distance from the river's headwaters and its delta at the sea. Water in the Colorado and its tributaries moved faster as a result and cut down deeper, creating the canyonland topography. Formation of approximately the current depth of the Colorado River's Grand Canyon by 1.2 mya further caused its tributaries to cut down even deeper. Headward erosion of one of those tributaries,

1034-432: A surface is eroded. Typically, physical erosion proceeds the fastest on steeply sloping surfaces, and rates may also be sensitive to some climatically controlled properties including amounts of water supplied (e.g., by rain), storminess, wind speed, wave fetch , or atmospheric temperature (especially for some ice-related processes). Feedbacks are also possible between rates of erosion and the amount of eroded material that

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1128-501: A wave closing the entrance of the joint. This then cracks it. Wave pounding is when the sheer energy of the wave hitting the cliff or rock breaks pieces off. Abrasion or corrasion is caused by waves launching sea load at the cliff. It is the most effective and rapid form of shoreline erosion (not to be confused with corrosion ). Corrosion is the dissolving of rock by carbonic acid in sea water. Limestone cliffs are particularly vulnerable to this kind of erosion. Attrition

1222-412: A weak bedrock (containing material more erodible than the surrounding rocks) erosion pattern, on the contrary, the amount of over deepening is limited because ice velocities and erosion rates are reduced. Glaciers can also cause pieces of bedrock to crack off in the process of plucking. In ice thrusting, the glacier freezes to its bed, then as it surges forward, it moves large sheets of frozen sediment at

1316-644: Is a sequence of sedimentary rock layers, first defined in the 1870s, that stretch south for 100 miles (160 km) from Bryce Canyon National Park through Zion National Park and into the Grand Canyon . Bryce Canyon is located within the Pink Cliffs, the highest and youngest rise within the Grand Staircase. In the Cretaceous , a shallow seaway spread into the interior of North America from

1410-546: Is already carried by, for example, a river or glacier. The transport of eroded materials from their original location is followed by deposition, which is arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10–40 times the rate at which soil erosion is occurring globally. At agriculture sites in the Appalachian Mountains , intensive farming practices have caused erosion at up to 100 times

1504-494: Is also more prone to mudslides, landslides, and other forms of gravitational erosion processes. Tectonic processes control rates and distributions of erosion at the Earth's surface. If the tectonic action causes part of the Earth's surface (e.g., a mountain range) to be raised or lowered relative to surrounding areas, this must necessarily change the gradient of the land surface. Because erosion rates are almost always sensitive to

1598-484: Is an example of extreme chemical erosion. Glaciers erode predominantly by three different processes: abrasion/scouring, plucking , and ice thrusting. In an abrasion process, debris in the basal ice scrapes along the bed, polishing and gouging the underlying rocks, similar to sandpaper on wood. Scientists have shown that, in addition to the role of temperature played in valley-deepening, other glaciological processes, such as erosion also control cross-valley variations. In

1692-409: Is distinguished from changes on the bed of the watercourse, which is referred to as scour . Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times. Thermal erosion is the result of melting and weakening permafrost due to moving water. It can occur both along rivers and at

1786-579: Is found as a lithified blanket sand that probably accumulated on beaches , in lagoons , and vast coal-producing swamps as the Cretaceous Seaway transgressed (advanced inland) over the region and later retreated. It sits unconformably on much older Jurassic formations that are not exposed in the immediate area (see geology of the Zion and Kolob canyons area for a discussion about these older sediments). Mud and silt were deposited on top of

1880-405: Is of two primary varieties: deflation , where the wind picks up and carries away loose particles; and abrasion , where surfaces are worn down as they are struck by airborne particles carried by wind. Deflation is divided into three categories: (1) surface creep , where larger, heavier particles slide or roll along the ground; (2) saltation , where particles are lifted a short height into

1974-625: Is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution . Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall ; bedrock wear in rivers ; coastal erosion by the sea and waves ; glacial plucking , abrasion , and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows . The rates at which such processes act control how fast

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2068-404: Is sparse and soil is dry (and so is more erodible). Other climatic factors such as average temperature and temperature range may also affect erosion, via their effects on vegetation and soil properties. In general, given similar vegetation and ecosystems, areas with more precipitation (especially high-intensity rainfall), more wind, or more storms are expected to have more erosion. In some areas of

2162-457: Is the main climatic factor governing soil erosion by water. The relationship is particularly strong if heavy rainfall occurs at times when, or in locations where, the soil's surface is not well protected by vegetation . This might be during periods when agricultural activities leave the soil bare, or in semi-arid regions where vegetation is naturally sparse. Wind erosion requires strong winds, particularly during times of drought when vegetation

2256-499: Is this process of chemical weathering that rounds the edges of hoodoos and gives them their lumpy and bulging profiles. In the winter, melting snow seeps into cracks and joints and freezes at night. The force of the expanding ice helps to erode the rock of the Claron Formation. Over 200 of these freeze/thaw cycles occur each year in Bryce Canyon. Frost wedging exploits and widens the nearly vertical joint planes that divide

2350-400: Is where particles/sea load carried by the waves are worn down as they hit each other and the cliffs. This then makes the material easier to wash away. The material ends up as shingle and sand. Another significant source of erosion, particularly on carbonate coastlines, is boring, scraping and grinding of organisms, a process termed bioerosion . Sediment is transported along the coast in

2444-664: The Great Plains , it is estimated that soil loss due to wind erosion can be as much as 6100 times greater in drought years than in wet years. Mass wasting or mass movement is the downward and outward movement of rock and sediments on a sloped surface, mainly due to the force of gravity . Mass wasting is an important part of the erosional process and is often the first stage in the breakdown and transport of weathered materials in mountainous areas. It moves material from higher elevations to lower elevations where other eroding agents such as streams and glaciers can then pick up

2538-608: The Gulf of Mexico in the south into Utah and later to the Arctic Ocean in the far north. Geologists call this shallow sea the Cretaceous Seaway or Western Interior Seaway. The seaway divided North America into two halves: an eastern portion dominated by the already ancient Appalachian Mountains and a western part composed primarily of the still growing Sevier Mountains; formed from shallow thrust faulting caused by

2632-625: The Paria River , eroded north-northwestward toward what is now Paria Amphitheater. The river took a route roughly parallel to and east of the Paunsaugunt Fault. Erosion from snow and rain that fall directly on the east-facing rim of the Paunsaugunt Plateau forms gullies that widen into alcoves and amphitheaters while differential erosion and frost wedging create the hoodoos . Streams on the plateau do not contribute to

2726-617: The Paunsaugunt that the park sits astride. Long, north–south-trending normal faults were either newly created or reactivated from older pre-existing faults; a plateau rose on one side of each fault while valleys subsided on the other as the crust was extended in an east–west direction. Two of these faults bound the Paunsaugunt Plateau; the Sevier on the west and the Paunsaugunt on the east. Movement along these two faults has displaced

2820-578: The Pine Hollow , sit on top of the Kaiparowits elsewhere in the region but are absent in the Bryce Canyon area. The sandstones and conglomerates of these formations record stream and river deposition starting in the Paleocene epoch. Uplift caused by a mountain -building episode called the Laramide orogeny lasted from the late Cretaceous around 70 mya to the early Paleocene. This hoisted

2914-503: The Sevier orogeny . As the shoreline moved back and forth, the Bryce area alternated from being part of the Sevier landmass to being under the Cretaceous Seaway. Alternating layers of nonmarine, intertidal, and marine sediments lay on top of each other as a result. Conglomerate , siltstone , and fossil -rich sandstone that together are up to 300 feet (90 m) thick mark the arrival of

Geology of the Bryce Canyon area - Misplaced Pages Continue

3008-737: The Timanides of Northern Russia. Erosion of this orogen has produced sediments that are now found in the East European Platform , including the Cambrian Sablya Formation near Lake Ladoga . Studies of these sediments indicate that it is likely that the erosion of the orogen began in the Cambrian and then intensified in the Ordovician . If the erosion rate exceeds soil formation , erosion destroys

3102-416: The accumulation zone above the glacial equilibrium line altitude), which causes increased rates of erosion of the mountain, decreasing mass faster than isostatic rebound can add to the mountain. This provides a good example of a negative feedback loop . Ongoing research is showing that while glaciers tend to decrease mountain size, in some areas, glaciers can actually reduce the rate of erosion, acting as

3196-551: The hadrosaurs . A flood plain crossed by rivers and lakes developed in the area. Mud and sand accumulated in this setting to become the gray sandstones and mudstones of the Kaiparowits Formation . This formation is up to 100 feet (30 m) thick in the Bryce Canyon area, but other parts of the Kaiparowits in the region are several hundreds of feet (tens of meters) thick. Two formations, the Canaan Peak and

3290-405: The impact of a falling raindrop creates a small crater in the soil , ejecting soil particles. The distance these soil particles travel can be as much as 0.6 m (2.0 ft) vertically and 1.5 m (4.9 ft) horizontally on level ground. If the soil is saturated , or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs. If

3384-455: The lower crust and mantle . Because tectonic processes are driven by gradients in the stress field developed in the crust, this unloading can in turn cause tectonic or isostatic uplift in the region. In some cases, it has been hypothesised that these twin feedbacks can act to localize and enhance zones of very rapid exhumation of deep crustal rocks beneath places on the Earth's surface with extremely high erosion rates, for example, beneath

3478-407: The surface runoff which may result from rainfall, produces four main types of soil erosion : splash erosion , sheet erosion , rill erosion , and gully erosion . Splash erosion is generally seen as the first and least severe stage in the soil erosion process, which is followed by sheet erosion, then rill erosion and finally gully erosion (the most severe of the four). In splash erosion ,

3572-499: The 21st century, a strong link has been drawn between the increase in storm frequency with an increase in sediment load in rivers and reservoirs, highlighting the impacts climate change can have on erosion. Vegetation acts as an interface between the atmosphere and the soil. It increases the permeability of the soil to rainwater, thus decreasing runoff. It shelters the soil from winds, which results in decreased wind erosion, as well as advantageous changes in microclimate. The roots of

3666-642: The Claron Formation by 2,000 feet (600 m) relative to the Paria and Sevier valleys. The Hurricane Fault marks the west edge of the Markagunt Plateau and is the topographic boundary between the Basin and Range and the Colorado Plateaus provinces. Cedar Breaks National Monument , which shares almost the same exposed geology and erosional features as Bryce Canyon National Park, sits on

3760-584: The Cretaceous Seaway. Called the Dakota Sandstone , it is the oldest formation exposed in the Bryce Canyon area but the youngest one exposed in the Zion and Kolob canyons area to the southwest. Abundant amounts of petrified wood , oyster beds containing millions of fossils, and coal are all found in the Dakota. In the Bryce Canyon area, this formation can be seen in the Paria Valley where it

3854-646: The Dakota Formation as the seaway became deeper and calmer in the area. The resulting dark gray to black Tropic Shale records the maximum transgression of the seaway into Utah and is 1,000 feet (300 m) thick in the Paria Amphitheater. It forms the unvegetated badlands seen in the Tropic Valley and is perhaps the most fossil-rich formation in the area; containing numerous straight-shelled and coiled ammonites . The Cretaceous Seaway

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3948-656: The East Fork of the Sevier River . Once this river flows through Bryce Amphitheater it will dominate the erosional pattern; replacing hoodoos with a V-shaped canyon and steep cliff walls typical of the weathering and erosional patterns created by rivers. A foreshadowing of this can be observed in Water Canyon while hiking the Mossy Cave Trail. A diversion canal has been taking a portion of the East Fork of

4042-537: The Paleocene to mid Oligocene but did not spread to the Bryce Canyon area until Eocene time. Large quantities of lakebed sediments were laid down in this system during the 20 million years of its existence from about 60 to 40 mya. Climate change and cycles caused the lakes in the system to expand and shrink through time. As they did so, they left beds of differing thickness and composition stacked atop one another; The limey oozes and mud were later lithified into

4136-463: The Pink Member of the Claron Formation. Internal layers of mudstone, conglomerate and siltstone interrupt the limestone horizontally. These layers are more resistant to attack by carbonic acid and they can therefore act as protective capstones of fins, windows and hoodoos. Many of the more durable hoodoos are capped with a type of magnesium -rich limestone called dolomite . Dolomite dissolves at

4230-713: The Sevier River Formation were laid down in valleys that were part of the ancestral Sevier River drainage system. Around 15 mya in Miocene time, tensional forces in Nevada to the west were so great that the crust was spread thin, creating the Basin and Range Province . These same forces segmented what is now the western part of the Colorado Plateau into nine different smaller plateaus, including

4324-559: The Sevier River through this section of the park for over 100 years. Erosion Erosion is the action of surface processes (such as water flow or wind ) that removes soil , rock , or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited . Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment

4418-433: The air, and bounce and saltate across the surface of the soil; and (3) suspension , where very small and light particles are lifted into the air by the wind, and are often carried for long distances. Saltation is responsible for the majority (50–70%) of wind erosion, followed by suspension (30–40%), and then surface creep (5–25%). Wind erosion is much more severe in arid areas and during times of drought. For example, in

4512-470: The base along with the glacier. This method produced some of the many thousands of lake basins that dot the edge of the Canadian Shield . Differences in the height of mountain ranges are not only being the result tectonic forces, such as rock uplift, but also local climate variations. Scientists use global analysis of topography to show that glacial erosion controls the maximum height of mountains, as

4606-522: The coast. Rapid river channel migration observed in the Lena River of Siberia is due to thermal erosion, as these portions of the banks are composed of permafrost-cemented non-cohesive materials. Much of this erosion occurs as the weakened banks fail in large slumps. Thermal erosion also affects the Arctic coast , where wave action and near-shore temperatures combine to undercut permafrost bluffs along

4700-409: The coastline. Where there is a bend in the coastline, quite often a buildup of eroded material occurs forming a long narrow bank (a spit ). Armoured beaches and submerged offshore sandbanks may also protect parts of a coastline from erosion. Over the years, as the shoals gradually shift, the erosion may be redirected to attack different parts of the shore. Erosion of a coastal surface, followed by

4794-411: The direction of the prevailing current ( longshore drift ). When the upcurrent supply of sediment is less than the amount being carried away, erosion occurs. When the upcurrent amount of sediment is greater, sand or gravel banks will tend to form as a result of deposition . These banks may slowly migrate along the coast in the direction of the longshore drift, alternately protecting and exposing parts of

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4888-405: The extremely steep terrain of Nanga Parbat in the western Himalayas . Such a place has been called a " tectonic aneurysm ". Human land development, in forms including agricultural and urban development, is considered a significant factor in erosion and sediment transport , which aggravate food insecurity . In Taiwan, increases in sediment load in the northern, central, and southern regions of

4982-582: The flood regions result from glacial Lake Missoula , which created the channeled scablands in the Columbia Basin region of eastern Washington . Wind erosion is a major geomorphological force, especially in arid and semi-arid regions. It is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage—especially after being increased far above natural rates by human activities such as deforestation , urbanization , and agriculture . Wind erosion

5076-407: The formation of alcoves or amphitheaters because they flow away from the rim. Erosion continues in this fashion today. The Pink Member of the Claron Formation is largely composed of easily eroded and relatively soft limestone. When rain combines with carbon dioxide it forms a weak solution of carbonic acid . This acid helps to slowly dissolve the limestone in the Claron Formation grain by grain. It

5170-660: The formation of vertical joints which were later preferentially eroded to form the free-standing pinnacles called hoodoos , badlands , and monoliths we see today. The formations exposed in the area of the park are part of the Grand Staircase . The oldest members of this super sequence of rock units are exposed in the Grand Canyon , the intermediate ones in Zion National Park , and its youngest parts are laid bare in Bryce Canyon area. A small amount of overlap occurs in and around each park. The Grand Staircase

5264-417: The growth of protective vegetation ( rhexistasy ) are a key element of badland formation. Valley or stream erosion occurs with continued water flow along a linear feature. The erosion is both downward , deepening the valley , and headward , extending the valley into the hillside, creating head cuts and steep banks. In the earliest stage of stream erosion, the erosive activity is dominantly vertical,

5358-411: The island can be tracked with the timeline of development for each region throughout the 20th century. The intentional removal of soil and rock by humans is a form of erosion that has been named lisasion . Mountain ranges take millions of years to erode to the degree they effectively cease to exist. Scholars Pitman and Golovchenko estimate that it takes probably more than 450 million years to erode

5452-598: The limestone and interbedded siltstone of the up-to-300 foot (90 m)-thick White Member of the Claron. This member erodes into white-colored monoliths that are found only at the highest elevations of the Paunsaugunt Plateau . Fossils are rare in the White Member and consist mainly of freshwater snails and clams , indicating that the lakes supported little life. Most arches and natural bridges in

5546-409: The local slope (see above), this will change the rates of erosion in the uplifted area. Active tectonics also brings fresh, unweathered rock towards the surface, where it is exposed to the action of erosion. However, erosion can also affect tectonic processes. The removal by erosion of large amounts of rock from a particular region, and its deposition elsewhere, can result in a lightening of the load on

5640-523: The lower parts of the formation. Lakes and east-flowing rivers became the dominant resting place for sediment following the retreat of the Cretaceous Seaway. The shales and sandstones of the locally 700 feet (200 m) thick Wahweap Formation were deposited in moving water (fluvial setting). This formation is part of the Grey Cliffs of the Grand Staircase mentioned previously. It contains abundant fossils of vertebrates , including dinosaurs such as

5734-418: The material and move it to even lower elevations. Mass-wasting processes are always occurring continuously on all slopes; some mass-wasting processes act very slowly; others occur very suddenly, often with disastrous results. Any perceptible down-slope movement of rock or sediment is often referred to in general terms as a landslide . However, landslides can be classified in a much more detailed way that reflects

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5828-407: The material has begun to slide downhill. In some cases, the slump is caused by water beneath the slope weakening it. In many cases it is simply the result of poor engineering along highways where it is a regular occurrence. Surface creep is the slow movement of soil and rock debris by gravity which is usually not perceptible except through extended observation. However, the term can also describe

5922-438: The mechanisms responsible for the movement and the velocity at which the movement occurs. One of the visible topographical manifestations of a very slow form of such activity is a scree slope. Slumping happens on steep hillsides, occurring along distinct fracture zones, often within materials like clay that, once released, may move quite rapidly downhill. They will often show a spoon-shaped isostatic depression , in which

6016-484: The morphologic impact of glaciations on active orogens, by both influencing their height, and by altering the patterns of erosion during subsequent glacial periods via a link between rock uplift and valley cross-sectional shape. At extremely high flows, kolks , or vortices are formed by large volumes of rapidly rushing water. Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called rock-cut basins . Examples can be seen in

6110-404: The most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone that erodes: suspended abrasive particles, pebbles , and boulders can also act erosively as they traverse a surface, in a process known as traction . Bank erosion is the wearing away of the banks of a stream or river. This

6204-531: The natural rate of erosion in the region. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes ) ecological collapse , both because of loss of the nutrient-rich upper soil layers . In some cases, this leads to desertification . Off-site effects include sedimentation of waterways and eutrophication of water bodies , as well as sediment-related damage to roads and houses. Water and wind erosion are

6298-592: The nearby Basin and Range topography. The greater Bryce area was uplifted as part of the High Plateaus by the same forces. Uplift of the Colorado Plateaus and the opening of the Gulf of California by 5 mya changed the drainage of the Colorado River and its tributaries, including the Paria River , which is eroding headward between two plateaus adjacent to the park. The uplift caused

6392-512: The northern part of the park and in a few places on the plateau rim. Among these are the 50-to-100-foot (20 to 30 m) thick Oligocene or Miocene -aged Boat Mesa Conglomerate and the Pliocene to early Pleistocene -aged Sevier River Formation . The Boat Mesa is made mostly of conglomerates with minor amounts of sandstone and some limestone from lakes, representing stream and overbank flood deposits. The brownish-gray sandstone and gravels of

6486-434: The nutrient-rich upper soil layers . In some cases, the eventual result is desertification . Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses. Water and wind erosion are the two primary causes of land degradation ; combined, they are responsible for about 84% of the global extent of degraded land , making excessive erosion one of

6580-526: The once lower uplands skyward while low-lying basins between them gradually subsided. Compression from the Laramide event deformed the land in the area to form the up to 5° dipping Bryce Canyon Anticline. All of the Canaan Peak, Pine Hollow, Kaiparowits, and Waheap formations, along with part of the underlying Straight Cliffs, were removed from the anticline's crest by erosion before the Claron Formation

6674-411: The order of a few centimetres (about an inch) or less and along-channel slopes may be quite steep. This means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow, removing soil to

6768-525: The order of events were, the High Plateaus region of the Colorado Plateau were by now nearly complete. Drainage of the Colorado Plateau was significantly altered by the opening of the Gulf of California . Rifting tore Baja California Peninsula northwestward from the Mexican mainland starting some 10 to 5 mya. The ancestral Colorado River responded to the regional downwarping by taking

6862-465: The park's fragile and colorful spires called hoodoos . Geologist Clarence Dutton called the iron oxide -rich lower member of the Claron the Pink Cliffs series due to its colorful appearance. A large system of shallow but expansive lakes and associated deltas covered several thousand square miles of what is now northwest Colorado and southwest Utah and Wyoming . These lakes existed from

6956-441: The park, including the famous Natural Bridge , were carved from sandstone beds in the Claron. A gap in the geologic record following deposition of the Claron Formation was interrupted 34 to 31 mya by eruptions from the nearby Marysvale volcanic field , which is located northwest of the park. Volcanic ash and lava from these flows are found less than 20 miles (30 km) from Bryce Canyon but at least some volcanic material

7050-656: The plains. Erosion incised these deposits between flood events and plant growth was abundant. Oxidation of the iron in the mud and silt turned the soil into hematite , giving it a pink and red hue. These sediments were later lithified into the up-to- 700 feet (200 m)-thick Pink Member of the locally Eocene-aged Claron Formation (previously called the Wasatch Formation). Channelized conglomerates of this member can be easily seen in Red Canyon along State Route 12 while its silt and mudstones compose most of

7144-556: The plants bind the soil together, and interweave with other roots, forming a more solid mass that is less susceptible to both water and wind erosion. The removal of vegetation increases the rate of surface erosion. The topography of the land determines the velocity at which surface runoff will flow, which in turn determines the erosivity of the runoff. Longer, steeper slopes (especially those without adequate vegetative cover) are more susceptible to very high rates of erosion during heavy rains than shorter, less steep slopes. Steeper terrain

7238-413: The relief between mountain peaks and the snow line are generally confined to altitudes less than 1500 m. The erosion caused by glaciers worldwide erodes mountains so effectively that the term glacial buzzsaw has become widely used, which describes the limiting effect of glaciers on the height of mountain ranges. As mountains grow higher, they generally allow for more glacial activity (especially in

7332-828: The rolling of dislodged soil particles 0.5 to 1.0 mm (0.02 to 0.04 in) in diameter by wind along the soil surface. On the continental slope , erosion of the ocean floor to create channels and submarine canyons can result from the rapid downslope flow of sediment gravity flows , bodies of sediment-laden water that move rapidly downslope as turbidity currents . Where erosion by turbidity currents creates oversteepened slopes it can also trigger underwater landslides and debris flows . Turbidity currents can erode channels and canyons into substrates ranging from recently deposited unconsolidated sediments to hard crystalline bedrock. Almost all continental slopes and deep ocean basins display such channels and canyons resulting from sediment gravity flows and submarine canyons act as conduits for

7426-515: The runoff has sufficient flow energy , it will transport loosened soil particles ( sediment ) down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of

7520-467: The second interval from the 19 myo Mount Belknap caldera. The Marysvale volcanic field collapsed under its own weight around 20 mya; likely due to weaknesses in the evaporites of the Carmel Formation some 5,000 feet (2,000 m) below. Folding and faulting of the Claron Formation from the collapse created Ruby's Inn thrust. A slight downwarp running east–west and perpendicular to

7614-586: The shore of the seaway. While the alternating layers of shale and sandstone mixed with massive coal deposits of the John Henry Member were laid down in swamps, lagoons and fluvial environments, one member, the Drip Tank, is not found in the Bryce Canyon area. This formation erodes into almost unclimbable cliffs and escarpments of whitish to yellow-gray sandstones with comparatively thin interbedded layers of shale and mudstone. Shark teeth are found in

7708-538: The shoreline and cause them to fail. Annual erosion rates along a 100-kilometre (62-mile) segment of the Beaufort Sea shoreline averaged 5.6 metres (18 feet) per year from 1955 to 2002. Most river erosion happens nearer to the mouth of a river. On a river bend, the longest least sharp side has slower moving water. Here deposits build up. On the narrowest sharpest side of the bend, there is faster moving water so this side tends to erode away mostly. Rapid erosion by

7802-593: The soil. Lower rates of erosion can prevent the formation of soil features that take time to develop. Inceptisols develop on eroded landscapes that, if stable, would have supported the formation of more developed Alfisols . While erosion of soils is a natural process, human activities have increased by 10-40 times the rate at which erosion occurs globally. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes ) ecological collapse , both because of loss of

7896-433: The terminus or during glacier retreat . The best-developed glacial valley morphology appears to be restricted to landscapes with low rock uplift rates (less than or equal to 2mm per year) and high relief, leading to long-turnover times. Where rock uplift rates exceed 2mm per year, glacial valley morphology has generally been significantly modified in postglacial time. Interplay of glacial erosion and tectonic forcing governs

7990-668: The thrust motion called the Bryce syncline was also created. Volcanic activity in the Marysvale and Bryce area ceased some 500,000 years ago. Basaltic rocks of the same age can be seen along the Sevier Fault near the entrance to Red Canyon; the dark colored volcanic rocks have been displaced by the fault some 900 feet (300 m) and are now in direct contact with the much older Claron Formation. Younger rock units were laid down but were mostly removed by subsequent uplift-accelerated erosion. Outcrops of these formations can be found in

8084-409: The transfer of sediment from the continents and shallow marine environments to the deep sea. Turbidites , which are the sedimentary deposits resulting from turbidity currents, comprise some of the thickest and largest sedimentary sequences on Earth, indicating that the associated erosional processes must also have played a prominent role in Earth's history. The amount and intensity of precipitation

8178-563: The two primary causes of land degradation ; combined, they are responsible for about 84% of the global extent of degraded land, making excessive erosion one of the most significant environmental problems worldwide. Intensive agriculture , deforestation , roads , anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall , and

8272-427: The valleys have a typical V-shaped cross-section and the stream gradient is relatively steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain. The stream gradient becomes nearly flat, and lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far

8366-473: The west edge of the Markagunt. The entire Colorado Plateau then started to uplift from near sea level to several thousand feet (over a kilometer) in elevation. An alternate theory is that the Laramide orogeny uplifted what is today the Basin and Range and the Colorado Plateau and that the tensional forces that formed the Basin and Range caused that region to subside relative to the Colorado Plateau. Whatever

8460-554: The world (e.g. western Europe ), runoff and erosion result from relatively low intensities of stratiform rainfall falling onto the previously saturated soil. In such situations, rainfall amount rather than intensity is the main factor determining the severity of soil erosion by water. According to the climate change projections, erosivity will increase significantly in Europe and soil erosion may increase by 13–22.5% by 2050 In Taiwan , where typhoon frequency increased significantly in

8554-491: The world (e.g. the mid-western US ), rainfall intensity is the primary determinant of erosivity (for a definition of erosivity check, ) with higher intensity rainfall generally resulting in more soil erosion by water. The size and velocity of rain drops is also an important factor. Larger and higher-velocity rain drops have greater kinetic energy , and thus their impact will displace soil particles by larger distances than smaller, slower-moving rain drops. In other regions of

8648-708: Was already retreating east and to the south by the time the locally 1,700 feet (500 m) thick Straight Cliffs Formation was deposited. Its members represent various stages in this process. The cliff-forming sandstone of the Tibbet Canyon Member was conformably deposited on top of the Tropic Shale in shallow marine and later near shore environments. Shale and sandstone from the Smoky Hollow Member were deposited on top of its basal layer of coal-rich mudstone in coastal swamps and lagoons on

8742-556: Was deposited. An angular unconformity therefore exists along the anticline's crest. The park also sits on the western gently dipping flank of the much larger Kaibab uplift , which was also formed as a result of the Laramide. Uplift from the Laramide paused briefly in the Eocene . Meandering streams flowed slowly over the resulting broad and almost featureless plains. Periodic but extensive floods inundated large areas perhaps once every 1,000 years; spreading mud, cobbles and fine silt over

8836-617: Was likely deposited directly in the park area only to be later removed by erosion. Most of the activity at the Marysvale volcanic field occurred during three separate intervals; ~34–22 mya, 22–14 mya and 9–5 mya. Dacites and andesites were erupted above an evolving batholith in the first interval. Crystal-rich ash from the 27-million-year-old (myo) Three Creeks caldera, 24 myo Big John caldera and 23 myo Monroe Peak caldera hardened into tuff . The second and third intervals saw eruptions of great quantities of rhyolites . Alkali -rich rhyolite erupted in

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