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Types Of Volcanoes
Mountains and hills can be characterized in several ways. Some mountains are volcanoes and can be characterized by the type of lava and eruptive history. Other mountains are shaped by glacial processes and can be characterized by their shape. Finally, many mountains can be characterized by the type of rock that make up their composition. Types of mountains according to geology Glacially sculpted mountains and hills * Arête * Drumlin * Esker * Flyggberg * Nunatak * Pyramidal peak * Whaleback mountain Volcanic mountains * Cinder cone * Complex volcano * Guyot * Lava cone * Lava dome * Mud volcano * Pancake dome * Pyroclastic cone * Pyroclastic shield * Shield volcano * Stratovolcano * Subglacial mound * Submarine volcano * Somma volcano * Tuya * Volcanic field * Volcanic plug Mountains with structure-controlled form * Bornhardt * Cuesta * Dome * Fault-block mountain * Fold mountain * Hogback * Homoclinal ridge * Table and mesa **Tepui (Guiana Highlands) * Traprock mount ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least above the surrounding land. A few mountains are inselberg, isolated summits, but most occur in mountain ranges. mountain formation, Mountains are formed through tectonic plate, tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through Slump (geology), slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce Alpine climate, colder climates than at sea level at similar latitude. These colder climates strongly affect the Montane ecosystems, ecosystems of mountains: different elevations hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Cone
Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption. Types of volcanic cones include stratocones, spatter cones, tuff cones, and cinder cones. Stratocone Stratocones are large cone-shaped volcanoes made up of lava flows, explosively erupted pyroclastic rocks, and igneous intrusives that are typically centered around a cylindrical vent. Unlike shield volcanoes, they are characterized by a steep profile and periodic, often alternating, explosive eruptions and effusive eruptions. Some have collapsed craters called calderas. The central core of a stratocone is commonly dominated by a central core of intrusive rocks that range from around to over several kilometers in diameter. This central core is surrounded by multiple generations of lav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault-block Mountain
Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by Tectonics, tectonic and localized stresses in Crust (geology), Earth's crust. Large areas of bedrock are broken up into blocks by Fault (geology), faults. Blocks are characterized by relatively uniform lithology. The largest of these fault blocks are called crustal blocks. Large crustal blocks broken off from tectonic plates are called terranes. Those terranes which are the full thickness of the lithosphere are called microplates. Continent-sized blocks are called variously ''microcontinents, continental ribbons, H-blocks, extensional allochthons and outer highs.'' Because most stresses relate to the tectonic activity of moving Plate tectonics, plates, most motion between blocks is horizontal, that is parallel to the Earth's crust by Fault (geology)#Strike-slip faults, strike-slip faults. However vertical movement of blocks produces much more dramatic results. Landforms (mounta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dome (geology)
A dome is a feature in structural geology where a circular part of the Earth's surface has been pushed upward, tilting the pre-existing layers of earth away from the center. In technical terms, it consists of symmetrical anticlines that intersect each other at their respective wikt:apex, apices. Intact, domes are distinct, rounded, sphere, spherical-to-ellipsoidal-shaped protrusions on the Earth's surface. A slice parallel to Earth's surface of a dome features concentric rings of stratum, strata. If the top of a dome has been eroded flat, the resulting structure in Multiview_orthographic_projection#Plan, plan view appears as a Bullseye_(target), bullseye, with the youngest rock layers at the outside, and each ring growing progressively older moving inwards. These strata would have been horizontal at the time of Deposition_(geology), deposition, then later deformed by the Tectonic uplift, uplift associated with dome formation. Formation mechanisms There are many possible mechani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuesta
A cuesta () is a hill or ridge with a gentle slope on one side, and a steep slope on the other. In geology, the term is more specifically applied to a ridge where a harder sedimentary rock overlies a softer layer, the whole being tilted somewhat from the horizontal. This results in a long and gentle backslope called a dip slope that conforms with the dip of resistant strata, called caprock. Where erosion has exposed the frontslope of this, a steep slope or escarpment occurs. The resulting terrain may be called scarpland. Definition In general usage, a cuesta is a hill or ridge with a gentle slope (backslope) on one side, and a steep slope (frontslope) on the other. The word is from Spanish: "flank or slope of a hill; hill, mount, sloping ground". In geology and geomorphology, cuesta refers specifically to an asymmetric ridge with a long and gentle backslope called a dip slope that conforms with the dip of a resistant stratum or strata, called caprock. The outcrop of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bornhardt
A bornhardt () is a dome-shaped, steep-sided, bald rock outcropping at least in height and several hundred metres in width. They are named after Wilhelm Bornhardt (1864–1946), a German geologist and explorer of German East Africa, who first described the feature. While ''bornhardt'' was originally used to sometimes denote a type of inselberg (literally island mountain—an isolated dome in an otherwise flat landscape), the term ''bornhardt'' is used in modern literature to refer to domed hills and mountains regardless of isolation; thus, not all bornhardts are inselbergs and not all inselbergs are bornhardts. Bornhardts are commonly composed of igneous rocks, often granites, but examples of gneiss, quartzite and arkose bornhardts exist. The Sugarloaf Mountain of Rio de Janeiro is a typical example of this landform and is the origin of the common bornhardt nickname "sugar loaf". Bornhardts are most easily seen in arid and semi-arid regions, but occur over a wide range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Plug
A volcanic plug, also called a volcanic neck or lava neck, is a volcano, volcanic object created when magma hardens within a Volcanic vent, vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising Volatile (astrogeology)#Igneous petrology, volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. In a plinian eruption the plug is destroyed and ash is ejected. Glaciation, Glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail. If a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform. Examples of volcanic plugs Africa Near the village of Rhumsiki in the Far North Region (Cameroon), Far North Province of Cameroon, Kapsiki Peak is an example of a volcanic plug and is one of the most phot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Field
A volcanic field is an area of Earth's Earth's crust, crust that is prone to localized volcano, volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes such as cinder cones. Lava flows may also occur. They may occur as a monogenetic volcanic field or a polygenetic volcanic field. Description Alexander von Humboldt observed in 1823 that geologically young volcanoes are not distributed uniformly across the Earth's surface, but tend to be clustered into specific regions. Young volcanoes are rarely found within cratons, but are characteristic of subduction zones, rift zones, or in ocean basins. Intraplate volcanoes are clustered along hotspot (geology), hotspot traces. Within regions of volcanic activity, volcanic fields are clusters of volcanoes that share a common magma source. Unlike a large volcano with satellite or subsidiary vents, a volcanic field's vents have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuya
A tuya is a flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet. They are rare worldwide, being confined to regions which were covered by glaciers and had active volcanism during the same period. As lava that erupts under a glacier cools very quickly and cannot travel far, it piles up into a steep-sided hill. If the eruption continues long enough, it either melts all the ice or emerges through the top of the ice and then creates normal-looking lava flows that make a flat cap on top of the hill. Discovering and dating the lava flows in a tuya has proven useful in reconstructing past glacial ice extents and thicknesses. Formation Tuyas are a type of subglacial volcano that consists of nearly horizontal beds of lava capping outward-dipping beds of fragmental volcanic rocks, and they often rise in isolation above a surrounding plateau. Tuyas are found in Iceland, British Columbia, the Santiam Pass region in Oregon, the Tuva, Tyva Republic i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somma Volcano
A somma volcano, also known as a sommian, is a volcanic caldera that has been partially filled by a new central cone. The type is named after Mount Somma ("Summit"), a stratovolcano in southern Italy with a summit caldera in which the upper cone of Mount Vesuvius has grown. Other examples of somma volcanoes can be found on Russia's Kamchatka Peninsula and the Kuril Islands, stretching south from Kamchatka to Hokkaidō, Japan. Some examples of somma volcanoes are the following: * Africa ** Mount Meru (Arusha Region, Tanzania) ** Pico do Fogo ( Fogo Island, Cape Verde) ** Piton de la Fournaise (Réunion, France) ** Teide, Pico Viejo, Montaña Blanca, and Las Canadas Crater (Tenerife, Canary Islands, Spain) * Americas ** Cosigüina (Chinandega, Nicaragua) ** Tecapa (Usulután Department, El Salvador) ** Mount Mazama (Crater Lake) and Wizard Island (Oregon, United States) ** Mount St. Helens and associated lava domes, ( Washington, United States) * Asia ** Ebeko ( Param ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Volcano
Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges alone are estimated to account for 75% of the magma output on Earth.Martin R. Speight, Peter A. Henderson, "Marine Ecology: Concepts and Applications", John Wiley & Sons, 2013. . Although most submarine volcanoes are located in the depths of seas and oceans, some also exist in shallow water, and these can discharge material into the atmosphere during an eruption. The total number of submarine volcanoes is estimated to be over one million (most are now extinct) of which some 75,000 rise more than above the seabed. Only 119 submarine volcanoes in Earth's oceans and seas are known to have erupted during the last 11,700 years. Hydrothermal vents, sites of abundant biological activity, are commonly found near submarine volcanoes. Effect of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subglacial Mound
A subglacial mound is a type of subglacial volcano formed when lava erupts beneath a thick glacier or ice sheet. The magma forming these volcanoes was not hot enough to melt a vertical pipe right through the overlying glacial ice, instead forming hyaloclastite and pillow lava deep beneath the glacial ice field. Once the glaciers had retreated, the subglacial volcano would be revealed, with a unique shape as a result of their confinement within glacial ice. They are somewhat rare worldwide, being confined to regions which were formerly covered by continental ice sheets and also had active volcanism during the same period. They are found throughout Iceland, Antarctica and the Canadian province of British Columbia. Subglacial mounds can be mistaken for cinder cones because they may have a similar shape. An example of this confusion is Pyramid Mountain in the Wells Gray-Clearwater volcanic field The Wells Gray-Clearwater volcanic field, also called the Clearwater Cone Group, is a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
