Yearly, the plateau area of the canyon receives about 19 inches 48 centimeters of rain, which often falls in fierce thunderstorms. Unable to be absorbed by the normally dry soil, the water washes off in sheets and flash floods, eroding much of the soil and rock in its path.
Water in the form of ice, however, is the greater erosive force in the canyon. In addition to rain, approximately inches centimeters of snow falls on the canyon per year.
Water from the snow runs into cracks and joints in the canyon's rocks, then freezes at night. As water freezes into ice, it expands. The expanding ice in the cracks eventually breaks off portions of the rock, leaving behind a changed rock shape.
This process is known as frost wedging. The composition of the rocks of the hoodoos plays a further part in their bizarre-looking form. The hoodoos are composed of four different types of rock, each of which varies in hardness and erodes at a different rate.
As different parts of the hoodoos erode at different times, the rock columns take on their wavy and pockmarked shape. When a continental plate and an oceanic plate converge, the oceanic plate which is denser slides beneath the continental plate in a process known as subduction. As a plate subducts beneath another, its leading edge begins to melt because of high temperature and pressure in the mantle.
This forms thick, flowing magma molten rock beneath the planet's surface. Less dense than the rock that surrounds it deep underground, the magma rises toward Earth's surface, forcing its way through weakened layers of rock. In most instances, the magma collects in underground reservoirs called magma chambers. It remains there until enough pressure builds up to eject it onto the planet's surface through vents called volcanoes. For further information, see the Volcano chapter.
Sometimes the magma does not collect in a chamber, but rises beneath a large, stable landmass. Unable to break through any cracks or vents, the magma exerts pressure on the land, causing it to rise upward in one piece. Geologists believe this uplifting process formed the Colorado Plateau about five million years ago. A lava plateau also called a basalt plateau or flood basalt is a special type of plateau, formed neither by the collision of continental plates nor by uplift.
Instead, this layered plateau is built up over millions of years by lava repeatedly pouring forth through fissures, or long narrow cracks in the ground. Lava is what magma is called once it reaches Earth's surface. The cracks could be where tectonic plates are separating or where pressure from magma underneath the crust has created cracks in it.
The most abundant element found in magma is silicon, in the form of the oxide silica. An oxide is a compound of an element and oxygen.
As magma cools, the silica crystallizes to become the mineral quartz. The amount of silica in magma determines how easily the magma flows. The higher the silica content, the slower the magma lava flows. Temperature also affects the flow rate of magma: the higher the magma's temperature, the more readily it flows.
The lava that floods the landscape to create a lava plateau is composed primarily of basalt, a hard, often glassy, black volcanic rock. Basalt has low silica content, and the lava it creates has a high temperature. These two properties combine to produce lava that flows quite rapidly. Erupting from cracks in the ground in thin sheets, basalt lava floods over the landscape, building up to form deposits thousands of feet thick. The most famous example of a lava plateau in the United States is the Columbia Plateau.
It covers most of southern Washington from its border with Idaho west to the Pacific Ocean and south into Oregon. The lava flows that accumulated to form the plateau occurred within the last seventeen million years. More than 40, square miles , square kilometers of lava covers the plateau.
In places, it measures 5, feet 1, meters thick. Roughly circular, the Colorado Plateau sprawls across southeastern Utah, northern Arizona, northwestern New Mexico, and western Colorado. It covers a land area of , square miles , square kilometers. Only the states of Alaska, California, Montana, and Texas cover a larger area.
While tectonic forces thrust the nearby Rocky Mountains into existence some forty to eighty million years ago, the Colorado Plateau remained structurally stable. Originally close to sea level, the plateau was slowly uplifted as a single mass approximately five million years ago.
Elevations on the plateau range from 3, to 14, feet to 4, meters. The average elevation is 5, feet 1, meters. An area of the state of Tamil Nadu in the western portion of the Deccan Plateau. The Deccan Plateau, which is largely made up of basalt lava, covers some , square miles in west-central India. Average yearly precipitation on the plateau is about 10 inches 25 centimeters. Because of the plateau's elevation and arid dry climate, there is limited plant cover.
Erosion by wind and water has resulted in the creation of many dramatic landforms. Rivers have cut thousands of miles of canyons within the plateau. Among these many canyons is the Grand Canyon, sculpted by the Colorado River. The pinnacles and spires of red rock in southwestern Utah's Bryce Canyon are among the most remarkable sights in the country. The Deccan Plateau of west-central India is the oldest and most stable area of land in India.
It is a lava plateau that formed over a period of one million or more years. Deccan comes from the Sanskrit work dakshina , meaning "south. The relatively flat plateau covers some , square miles , square kilometers , encompassing the states of Andhra Pradesh, Karnataka, Kerala, and Tamil Nadu. Two mountain ranges, the Western and Eastern Ghats, flank it. In spots, the basalt lava flows that created it accumulated to a thickness of 6, feet 1, meters.
In its western regions, the plateau averages about 2, feet meters in elevation; in its eastern parts, it averages 1, feet meters. As a result of this difference in elevation from one side to the other, almost all rivers on the plateau flow from west to east and drain into the Bay of Bengal. The largest volcanic eruptions in Earth's history occurred about million years ago in present-day central Russia.
In these eruptions, which scientists believe lasted for , to 1 million years, basalt lava flowed out of cracks in the ground, forming what is now known as the Siberian Traps.
An enormous stretch of rolling land, it covers about , square miles 1,, square kilometers. Heights on this vast plateau range from 1, to 2, feet to meters. The lava that created the Siberian Traps would form a layer 10 feet 3 meters thick if spread out evenly across the planet. Scientists speculate that the lava on the plateau came from magma that originated some 1, miles 3, kilometers beneath Earth's crust.
Some scientists have even argued that the rapid volcanic event behind the plateau's formation also brought about the largest extinction of animals in Earth's history. As many as 95 percent of all animal species on the planet were wiped out in an extinction that occurred around the same time period. The scientists point out that the dust and ash released by the lava flows could have blocked out the Sun's light, killing off plant life around the world, a necessary food source for animals.
Or great amounts of carbon dioxide released by the flows could have encircled the planet, trapping the Sun's heat and raising temperatures worldwide, killing many life forms. The Tibetan Plateau is the highest and most widespread plateau in the world. Many believe it is probably the largest and highest area ever to exist in Earth's history.
The plateau covers some , square miles 2. The Tibetan Plateau is the highest and most widespread plateau in the world, with an average altitude of 16, feet.
It also contains the two highest peaks in the world, Mount Everest and Mount K2, and has the deepest canyon in the world, the Yarlung Zangbo. Referred to as the "roof of the world," the plateau has an average elevation over 16, feet 5, meters. It contains fourteen mountains that rise higher than 26, feet 8, meters and hundreds that rise more than 22, feet 7, meters. The plateau itself is still geologically active and continues to rise, gaining an average of 0. Approximately forty to fifty million years ago, the northward-moving Indian Plate rammed into the Eurasian Plate, creating what would eventually become the Himalayan Mountains and the Tibetan Plateau.
Geologists have long known that the crust beneath the plateau measures approximately 40 miles 65 kilometers in depth, roughly twice that of the average continental crust.
Only recently have scientists discovered that the plateau is supported by a bed of hot magma molten rock. Since magma is less dense lighter than cold, crustal rock, this bed of magma has helped raise the plateau as a single mass to such a great height. Baars, Donald L.
Ladd, Gary. Williams, David B. A Naturalist's Guide to Canyon Country. Dissected plateaus are also highly eroded by rivers and broken by deep narrow valleys. Intermontane plateaus are bordered by mountains and are the highest in the world. Continental plateaus are bordered by the plains or oceans on all sides forming away from mountains.
Example: the Antarctic Plateau in East Antarctica. Piedmont plateaus are bordered by a plain or a sea on one side and by mountains on the other. It is formed out of the collision of the Indo-Australian and Eurasian tectonic plates. Mexican Plateau is another high altitude plateau in North America. The Deccan Plateau is the largest Indian plateau in western and southern India located between two mountain ranges, the Eastern Ghats and the Western Ghats.
Extending over eight states of India including significant parts of Andhra Pradesh, Karnataka, Maharashtra, and Telangana, the Deccan Plateau encompasses a wide range of habitats and is rich in mineral ores like iron ore and mica in Chotanagpur region, and diamonds, gold, and others in the Golconda region.
It is the northernmost part of Western Australia and formed due to the volcanic eruption. This plateau is rich in mineral deposits such as iron, gold, silver, diamond, pearl, lead, zinc, kimberlite diamond-bearing rock and oil. The Colorado Plateau or the Colorado Plateau Province is the largest plateau in America lying in its southwestern part. Outside the Washington, DC metropolitan area, this plateau is the greatest attraction of U.
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