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Ceboruco
Ceboruco is a dacitic stratovolcano located in Nayarit, Mexico, northwest of the Trans-Mexican Volcanic Belt. The largest eruption, the Jala Plinian eruption, was around 930 AD ±200, VEI 6, releasing of tephra. The most recent and best documented eruption from Ceboruco lasted from 1870–1875, with fumarole activity lasting well into the 20th century. The mountain features one large caldera, created during the Jala eruption, with a smaller crater nested inside that formed when the Dos Equis lava dome collapsed during the Coapales eruption around 1100 AD. Within both of these craters, are several explosive volcanic features, including scoria deposits, lava domes, and pyroclastic domes, or cinder cone volcanoes. Cooled lava flows preserved around the volcano keep a record of the recent eruptions. Before the Jala eruption, there is record of one major lava flow, called the Destiladero flow. During the 500 years after the Jala eruption, the volcano was at its most a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jala, Nayarit
Jala () is both a municipality and a town in the Mexican state of Nayarit. the population of the municipality was 16,071, in a total area of 364.60 square kilometers. The population of the municipal seat of the same name was 9,631. The name Jala—place where there is a lot of sand—is derived from the Nahuatl word ''xali'', which means ''sand'', and the variant ''tla'', which means ''place with an abundance of''. The municipality of Jala is located in the southern part of the state of Nayarit; between parallels 21° 5’ and 21° 20’ latitude north and meridians 104° 18’ and 104° 31’ longitude west. It is bounded in the north by the municipalities of Santa María del Oro and La Yesca; in the south by the municipalities of Ahuacatlán and Ixtlán del Río; in the east with Ixtlán del Río and in the west with Santa María del Oro. The Rio Grande de Santiago passes in the north of the municipality. The economy is based on agriculture with the main crops being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nayarit
Nayarit (), officially the Free and Sovereign State of Nayarit ( es, Estado Libre y Soberano de Nayarit), is one of the 31 states that, along with Mexico City, comprise the Federal Entities of Mexico. It is divided in 20 municipalities and its capital city is Tepic. It is bordered by the states of Sinaloa to the northwest, Durango to the north, Zacatecas to the northeast and Jalisco to the south. To the west, Nayarit has a significant share of coastline on the Pacific Ocean, including the islands of Marías and Marietas. The beaches of San Blas and the so-called "Riviera Nayarit" are popular with tourists. Besides tourism, the economy of the state is based mainly on agriculture and fishing. It is also one of two states where the tarantula species ''Brachypelma klaasi'' is found, the other being Jalisco. Home to Uto-Aztecan indigenous peoples such as the Huichol and Cora, the region was exposed to the ''conquistadores'', Hernán Cortés and Nuño de Guzmán, in the 16t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Nayarit
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landforms Of Nayarit
A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great ocean basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, stratification, rock exposure and soil type. Gross physical features or landforms include intuitive elements such as berms, mounds, hills, ridges, cliffs, valleys, rivers, peninsulas, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodies and sub-surface features. Mountains, hills, plateaux, and plains are the fou ... [...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 Valentine 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dacite
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz. Dacite is relatively common, occurring in many tectonic settings. It is associated with andesite and rhyolite as part of the subalkaline volcanic rock, subalkaline tholeiite, tholeiitic and calc-alkaline magma series. Composition Dacite consists mostly of plagioclase feldspar and quartz with biotite, hornblende, and pyroxene (augite or enstatite). The quartz appears as rounded, corroded phenocrysts, or as an element of the ground-mass. The plagioclase in dacite ranges from oligoclase to andesine and labradorite. Sanidine occurs, although in small proportions, in some dacites, and when abundant gives rise to rocks that form rhyodacite, transitions to the rhyolites. The rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhyodacite
Rhyodacite is a volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of those plutonic rocks that are intermediate in composition between monzogranite and granodiorite. Rhyodacites form from rapid cooling of lava relatively rich in silica and low in alkali metal oxides. Description Under IUGS guidelines, rhyodacites are not formally defined in either the QAPF classification, used to classify igneous rocks by their mineral content, or the TAS classification, used to classify volcanic rocks chemically. However, the IUGS allows the use of the term to describe rocks close to the boundary between the rhyolite and dacite fields in each classification scheme. Rhyodacite then describes a fine-grained igneous rock containing between 20% and 60% quartz and in which plagioclase makes up about two-thirds of the total feldspar content. Such a rock will contain between 69% and 72% silica by weight. The U.S. Geological Survey defines rhyodacite ... [...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 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 gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andesitic
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust. The name ''andesite'' is derived from the Andes mountain range, where this rock type is found in abundance. It was first applied by Christian Leopold von Buch in 1826. Description Andesite is an aphanitic (fine-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the feldsp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trachyandesite
Trachyandesite is an extrusive igneous Rock (geology), rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by Sodium, sodic plagioclase and alkali feldspar. It is formed from the cooling of lava enriched in alkali metals and with an intermediate content of silica. The term ''trachyandesite'' had begun to fall into disfavor by 1985 but was revived to describe extrusive igneous rocks falling into the S3 field of the TAS classification. These are divided into sodium-rich benmoreite and potassium-rich latite. Trachyandesitic magma can produce explosive Plinian eruptions, such as happened at Mount Tambora, Tambora in 1815. The 2010 eruptions of Eyjafjallajökull, Eyjafjallajökull 2010 eruption (VEI4), which disrupted European and transatlantic air travel from 14–18 October 2010, for some time was dominated by trachyandesite. Petrology Trachyandesite is characterized by a silica content near 58% and a total alkali oxide cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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