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A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term 'rock formation' can also refer to specific sedimentary strata or other rock unit in stratigraphic and petrologic studies. A rock structure can be created in any rock type or combination: *Sedimentary rocks are created by a variety of processes but usually involving deposition, grain by grain, layer by layer, in water or, in the case of terrestrial sediments, on land through the action of wind or sometimes moving ice. Erosion later exposes them in their current form. An example is Bryce Canyon National Park in Utah. *Metamorphic rocks are created by rocks that have been transformed into another kind of rock, usually by some combination of heat, pressure and chemical alteration. An example are the Seneca Rocks in West Virginia. *Igneous rocks are created when molten rock cools and solidifies, with or without crystallization. They may be either plutonic bodies or volcanic extrusives. Again, erosive forces sculpt their current forms. An example is Half Dome in Yosemite National Park. Geologists have created a number of terms to describe different rock structures in the landscape that can be formed by natural processes: *Inselberg or monadnock is a residual relief feature. It can be an isolated hill, a knob, ridge or small mountain that rises abruptly, like an island, from a gently sloping or virtually level surrounding plain. ''Inselberg'' is a German word that means "island mountain". Uluru/Ayers Rock in Australia is a noted example. *Peak *Stack *Mesa *Butte *Escarpment *Gorge *Sea cliff *River cliff *Stone run *Crag *Tor *Promontory is a prominent mass of land which overlooks lower lying land or a body of water. Here is a list of rock formations by continent. ==Asia== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「List of rock formations」の詳細全文を読む スポンサード リンク
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