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Felsic. In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz. [1] It is contrasted with mafic rocks, which are relatively richer in magnesium and iron. Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen ...
Eruptions can last anywhere from hours to days, with longer eruptions being associated with more felsic volcanoes. Although they are usually associated with felsic magma, Plinian eruptions can occur at basaltic volcanoes, if the magma chamber differentiates with upper portions rich in silicon dioxide, [40] or if magma ascends rapidly. [42]
List of largest volcanic eruptions. The 1991 eruption of Mount Pinatubo, the largest eruption since 1912, is dwarfed by the eruptions in this list. In a volcanic eruption, lava, volcanic bombs, ash, and various gases are expelled from a volcanic vent and fissure. While many eruptions only pose dangers to the immediately surrounding area, Earth ...
Taal Volcano (IPA:; Tagalog: Bulkang Taal) is a large caldera filled by Taal Lake in the Philippines. [1] Located in the province of Batangas about 50 kilometers (31 mi) south of Manila, the volcano is the second most active volcano in the country with 38 recorded historical eruptions, all of which were concentrated on Volcano Island, near the middle of Taal Lake. [3]
Rhyolite (/ ˈraɪ.əlaɪt / RY-ə-lyte) [1][2][3][4] is the most silica -rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase.
Mechanism of formation. Bimodal volcanism is normally explained as a result of partial melting of the crust, creating granitic magmas, during the emplacement of large volumes of relatively hot basaltic magma from a mantle source. The two magma types then form separate magma chambers giving rise to periodic eruption of both types of lava. [7][8]
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate ...
Cinder cone. A cinder cone (or scoria cone[1]) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. [2][3] The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent.