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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] |
Mayon Volcano As Of March 2020
Mayon (; , ), also known as Mount Mayon and Mayon Volcano is an active stratovolcano in the Provinces of the Philippines, province of Albay in Bicol Region, Bicol, Philippines. A popular tourist spot, it is renowned for its "perfect cone" because of its symmetric Volcanic cone, conical shape, and is regarded as sacred in Philippine mythology. The volcano with its surrounding landscape was declared a national park on July 20, 1938, the first in the nation. It was reclassified as a Nature park, natural park and renamed the Mayon Volcano Natural Park in 2000."Protected Areas in Region 5" . Protected Areas and Wildlife Bureau. Retrieved on October 15, 2011. It is the centerpiece of the Albay Biosphere Reserve, declared by UNESCO in 2016, and is currently being nominated as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, fault (geology), fault or tectonics, tectonic breccia, igneous breccia, Impact event, impact breccia, and Hydrothermal circulation, hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like Conglomerate (geology), conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from Conglomerate (geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit of rock or an unconsolidated deposit is called an ''aquifer'' when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the ''water table''. Groundwater is Groundwater recharge, recharged from the surface; it may discharge from the surface naturally at spring (hydrosphere), springs and Seep (hydrology), seeps, and can form oasis, oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction water well, wells. The study of the distribution and movement of groundwater is ''hydrogeology'', also called groundwater hydrology. Typically, groundwater is thought o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Country Rock (geology)
In geology, country rock is the rock native to an area, in contrast to any intrusion of viscous geologic material, commonly magma, or perhaps rock salt (in salt domes) or unconsolidated sediments. Magma is typically less dense than the rock it intrudes, widening and filling existing cracks, sometimes melting the already-existing country rock. The term "country rock" is similar to, and in many cases interchangeable with, the terms basement and wall rocks. Country rock can denote the widespread lithology of a region in relation to the rock which is being discussed or observed. Geologic settings Settings in geology when the term ''country rock'' is used include: Igneous intrusions When describing a pluton or dike, the igneous rock can be described as intruding the surrounding ''country rock'', the rock into which the pluton has intruded.Newfoundland and LabradorGlossary of Geological Terms Accessed June 2018. When country rock is intruded by a dike, perpendicular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palagonite
Palagonite is an alteration product from the interaction of water with volcanic glass of chemical composition similar to basalt. Palagonite can also result from the interaction between water and basalt melt. The water flashes to steam on contact with the hot lava and the small fragments of lava react with the steam to form the light-colored palagonite tuff cones common in areas of basaltic eruptions in contact with water. An example is found in the pyroclastic cones of the Galapagos Islands. Charles Darwin recognized the origin of these cones during his visit to the islands. Palagonite can also be formed by a slower weathering of lava into palagonite, resulting in a thin, yellow-orange rind on the surface of the rock. The process of conversion of lava to palagonite is called ''palagonitization.'' Palagonite soil is a light yellow-orange dust, comprising a mixture of particles ranging down to sub-micrometer sizes, usually found mixed with larger fragments of lava. The color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phreatic Eruption
A phreatic eruption, also called a phreatic explosion, ultravulcanian eruption or steam-blast eruption, occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from ) causes near-instantaneous evaporation of water to steam, resulting in an explosion of steam, water, ash, rock, and volcanic bombs. At Mount St. Helens in Washington state, hundreds of steam explosions preceded the 1980 Plinian eruption of the volcano. A less intense geothermal event may result in a mud volcano. Phreatic eruptions typically include steam and rock fragments; the inclusion of liquid lava is unusual. The temperature of the fragments can range from cold to incandescent. If molten magma is included, volcanologists classify the event as a phreatomagmatic eruption. These eruptions occasionally create broad, low-relief craters called '' maars''. Phreatic explosions can be accompanied by carbon dioxide or hydrogen sulfide gas-emissions. Carbon diox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koko Crater
Koko Crater ( Hawaiian: ''Kohelepelepe'' or ''Puʻu Mai'') is an extinct tuff cone located on the Hawaiian island of Oʻahu near Hawaiʻi Kai. It is northeast of Hanauma Bay and south of the Koʻolau Range. Geology Koko Crater is a part of the Honolulu Volcanics, which were craters that formed as vents of the Koʻolau Volcano during its rejuvenation stage. Other notable landmarks within the Honolulu Volcanics include nearby Hanauma Bay and the well-known Diamond Head crater. Koko Crater, Hanauma Bay and other nearby tuff cones form the Koko Rift Zone, which marks the latest episode of volcanic activity on the island of Oahu. Radiocarbon dating suggests that the latest eruption within the Koko Rift Zone occurred 7,000 years ago, although the validity of these results are disputed. Its elevation is 1,208 ft (368 m), making it the tallest and most preserved tuff cone in the area. Trail During World War II, the US military built bunkers on top of Koko Crater with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taffy (candy)
Taffy is a type of candy invented in the United States, made by stretching or pulling a sticky mass of a soft candy base, made of Boiling, boiled sugar, butter, vegetable oil, flavorings, and Food coloring, colorings, until it becomes Aeration, aerated (tiny air bubbles produced), resulting in a light, fluffy and chewy candy. When this process is complete, the taffy is rolled, cut into small pieces and wrapped in wax paper to keep it soft. It is usually pastel (color), pastel-colored and fruit-flavored, but other flavors are common as well, including molasses and the "classic" (unflavored) taffy. Definition and etymology The word ''taffy'', referring to the boiled candy, is first known to have appeared in the United States circa 1817. The word is also used metaphorically to refer to insincere flattery. The ''Oxford English Dictionary'' dates the first written record of the word ''toffee'' in the forms ''tuffy, toughy'' to 1825 and identifies it as a southern British dialecta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase feldspar. Mafic materials can also be described as ferromagnesian. History The term ''mafic'' is a portmanteau of "magnesium" and "ferric" and was coined by Charles Whitman Cross, Joseph P. Iddings, Louis V. Pirsson, and Henry Stephens Washington in 1912. Cross' group had previously divided the major rock-forming minerals found in igneous rocks into ''salic'' minerals, such as quartz, feldspars, or feldspathoids, and ''femic'' minerals, such as olivine and pyroxene. However, micas and aluminium-rich amphiboles were excluded, while some calcium minerals containing little iron or magnesium, such as wollastonite or apatite, were included in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Fountain
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is often also called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. Etymology The word ''lava'' comes from Italian and is probably derived from the Latin wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puu Oo Cropped
Puu or Pu'u is a Hawaiian word for any protuberance, from a pimple to a hill, and can refer to: * Puu Kukui, mountain peak in Hawaii * Pu'u Huluhulu (Hawaii Route 200) * Puʻu ʻŌʻō (Puu Oo), volcanic cone in Hawaii * Setsuna Meioh (Sailor Pluto), ''Sailor Moon'' character * Puu (YuYu Hakusho), a major secondary character from Yu Yu Hakusho {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
