US Geochemical provides the most cost effective soil geochemical analysis available to the oil and gas exploration industry. Incomprehensible terms in geography make reading and understanding really boring. This Buzzle article lists the comprehensive compilation of geography definitions. Ocean Basin The shape of the land, Forces and changes, Spotlight on famous forms, For More Information. Photo by Onkelchen. Plateaus, plains, valleys, rolling hills, and volcanic. Yet the largest underwater mountains are higher than. About the Authors REE D WICANDE R is a geology professor at Central Michigan University where he teaches physical geology, historical geology, prehistoric life, and. How radiometric dating works in general Radioactive elements decay gradually into other elements. The original element is called the parent, and the result of the. These oceanscapes,. The shape of the land. Ocean basins are that part of Earths surface that extends seaward. The Cracks Between The Plates Of The Lithosphere Are Called A Mixture' title='The Cracks Between The Plates Of The Lithosphere Are Called A Mixture' />Chapter 13 Evolution of Continents and Oceans. The theory of plate tectonics is nowadays more or less universally accepted by geologists, and I have mentioned the. Retrouvez toutes les discothque Marseille et se retrouver dans les plus grandes soires en discothque Marseille. ENVIRONMENTAL SCIENCE DEMYSTIFIED. LINDA D. WILLIAMS. McGRAWHILL New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul. Continental Margins. Zones separating the part of a continent above sea level from the deepsea floor. The true geologic margin of a continent where continental. The Cracks Between The Plates Of The Lithosphere Are Called A Mixture' title='The Cracks Between The Plates Of The Lithosphere Are Called A Mixture' />Basins lie. From there. they drop steeply down into the deepest trenches. The oceans and seas of. Earths surface. Ocean basins occupy more than 7. Many sources include the continental margins as part of the ocean basins. They are part of. Earth that forms the. The transition between continental crust and oceanic crust. Continental crust is composed mostly of. Although they differ in. Granite forms when magma with a high silica content cools. Earths surface basalt forms when magma with a. Earths. surface. For. Canning Basin, western Australia. Ocean basins are that part of. Earths surface that extends seaward from the continental. PHOTOGRAPH REPRODUCED BY PERMISSION OF THE. CORBIS CORPORATION. Continental margin. By ocean basins, this discussion is referring to what may be termed the. The four main ocean. Pacific, Atlantic, Indian, and Arctic Oceans. The. Pacific Ocean, which occupies about one third of Earths surface. Its basin also has the greatest average depth at. The Atlantic Ocean basin is half. Pacific Ocean and is not quite as deep, averaging. While slightly smaller in size than the. Atlantic Ocean basin, the Indian Ocean basin sits at a lower average. The Arctic Ocean basin is less than 1. Pacific Ocean basin and lies at an average depth. All ocean basins contain certain primary features mid ocean ridges. BISS ul plains, trenches, and seamounts. Perhaps the most impressive features found on all ocean basins are long. These. elevated ridges mark the area where sections of oceanic crust are pulling. As they do, hot magma liquid rock emerges from. The lava cools and attaches to the trailing. Additional lava is deposited by the thousands of. The large depression that is created between the spreading sections is. Mid ocean ridges are divided into three groups. Ridges that. spread slowly, from 0. The valley may be 6 miles 1. Ridges that are. classified as medium spread at a rate of 2 to 4 inches 5 to 1. The valleys of these ridges may be up to 3 miles 5. Street Fighter Ii Champion Edition Pc Engine Duo. Finally, fast spreading ridges open up at a rate of 4 to 8 inches. Their rift valleys are much smoother in. On average, these small valleys are only 3. In most locations, mid ocean ridges are 6,5. In a few places, however, they actually. Iceland in the North Atlantic. Azores west of the coast of Portugal, and Tristan de Cunha in the. Atlantic midway between southern Africa and South America are. The most studied mid ocean ridge in the world is the Mid Atlantic Ridge. It begins at the tip of Greenland and runs down the center of the Atlantic. Ocean between the Americas on the west and Europe and Africa on the east. It ends its course at the southern tip of the African continent. At that. point, the ridge continues around the eastern edge of Africa as the. Southwest Indian Ridge. That ridge then divides near the center of the. Indian Ocean basin into the Central Indian Ridge that runs north into the. African continent and the Southeast Indian Ridge that runs east below the. Australian continent. The ridge continues eastward along the southern. Pacific Ocean basin as the Pacific Antarctic Ridge. It. eventually heads northward along the western coastline of South and. Central America as the East Pacific Rise. These mid ocean ridges combine to form a global undersea mountain system. Extending more than 4. Earth. Snaking its way between the continents, the ridge system encircles. Whereas the seams form a. The. offsets are called fracture zones. These breaks in the ridge line are. Earths crust along which. Ocean crust on. either side of a fault in a fracture zone slides in opposite directions. This helps relieve tension created when different sections of a mid ocean. The faults form deep, linear gouges. Crust in a fracture zone looks like it. The largest fracture zone occurs. Mid Atlantic Ridge, offsetting it by 5. The relatively flat areas of ocean basins between continental margins and. They are generally found at. Likely the most. level places on Earth, they are far flatter than any plain on dry land. They have gentle slopes of less than 1 foot 0. The flatness of abyssal plains is due to an accumulation of layers of. Much of this rock debris has been washed off. It is. carried down continental slopes by turbidity currents, turbulent mixtures. Pulled by gravity, these currents may surge. When the currents reach the ocean basin, they slow and the sediment they. In many areas, these sediment layers. The sediments cover many of. In places where the layers of sediment are thinner, gently sloping hills. Known as abyssal hills, these low, oval shaped hills are. The deepest parts of ocean basins are trenches, which may descend over. These long. narrow, canyonlike structures are formed where sections of oceanic crust. Thus, trenches. are often found parallel to continental margins and the seaward. Ocean basin Words to Know. Abyssal hill. A gently sloping, small hill, typically of volcanic origin, found on. Abyssal plain. The relatively flat area of an ocean basin between a continental. Asthenosphere. The section of the mantle immediately beneath the lithosphere that is. Continental drift. The hypothesis proposed by Alfred Wegener that the continents are not. Earth over time. Continental margin. The submerged outer edge of a continent, composed of the continental. Convection current. The circular movement of a gas or liquid between hot and cold areas. Crust. The thin, solid outermost layer of Earth. Fault. A crack or fracture in Earths crust along which rock on one. Fracture zone. An area where faults occur at right angles to a main feature, such as. Guyot. An undersea, flat topped seamount. Hot spot. An area beneath Earths crust where magma currents rise. Lithosphere. The rigid uppermost section of the mantle combined with the crust. Mantle. The thick, dense layer of rock that lies beneath Earths crust. Mid ocean ridge. A long, continuous volcanic mountain range found on the basins of all. Paleomagnetism. The study of changes in the intensity and direction of Earths. Plates. Large sections of Earths lithosphere that are separated by. Plate tectonics. The geologic theory that Earths crust is composed of rigid. Rift valley. The deep central crevice in a mid ocean ridge also, a valley or. Seafloor spreading. The process by which new oceanic crust is formed by the upwelling of. Seamount. An isolated volcanic mountain that often rises 3,2. Subduction zone. A region where two plates come together and the edge of one plate. Trench. A long, deep, narrow depression on the ocean basin with relatively. Turbidity current. A turbulent mixture of water and sediment that flows down a. Japan, the Philippines, and the Aleutian. Islands. Of the twenty two trenches that have been identified around the. Pacific Ocean basin, three in the. Atlantic Ocean basin, and one in the Indian Ocean basin. Seamounts are isolated volcanic mountains that often rise 3,2. Sometimes. seamounts rise above sea level to create islands. Geologists estimate that. Seamounts usually form near mid ocean ridges or. Earths. crust to form volcanoes. Hot spot plumes may exist for millions of years. As a section of oceanic crust moves over the hot spot, a chain of. The Hawaiian Islands are an example of such. When volcanic activity ceases, a seamount begins to erode and collapse. If wave action and weathering continue long enough. An undersea, flat topped seamount is called a guyot pronounced GHEE oh. These types of seamounts are common in the western Pacific Ocean. Glomar Challenger. In 1. 96. 8, the oceanographic drilling and coring vessel. Glomar Challenger. Earth. From its platform, it was possible to lower up to 2. During her fifteen years of operation, the.