B) granite; intrusive rock that formed from cooling of relatively high silica magma 2. porphyritic andesite -Sediments are solid fragments of inorganic or organic material that come from the weathering of rock and solid . The composition of magma depends on the rock it was formed from (by melting), and the conditions of that melting. 7. obsidian, Which of the following is characteristic of pegmatites? It is commonly grey and porphyritic. A stock is a type of pluton with less surface exposure than a batholith and may represent a narrower neck of material emerging from the top of a batholith. C. basalt This section will focus on the common igneous bodies which are found in many places within the bedrock of Earth. If a magma chamber encounters an enormous amount of pressure, however, it may fracture the rock around it. A. peridotite For information on user permissions, please read our Terms of Service. E) rhyolite: extrusive rock that formed from cooling of relatively low silica magma D) peridotite, Most magmas are dominantly molten rock (a liquid called "melt"). A. convergent plate boundaries In some cases, individual plagioclase crystals can be zoned from calcium-rich in the centre to more sodium-rich around the outside. Igneous rocks form when melted rock cools. Types of MagmaAll magma contains gases and a mixture of simple elements. Sills are another type of intrusive structure. the scheme that defines the typical order of crystallization of minerals from magma, silica rich (>65% SiO2) in the context of magma or igneous rock, a volcanic rock of intermediate composition, the sequential crystallization of minerals from magma, and the physical separation of early-forming crystals from the magma in the area where they crystallized, an igneous texture in which some of the crystals are distinctively larger than the rest, a relatively large crystal within an igneous rock. D) the lava in the crystallizing magma chamber before eruption. D) texture and mineral composition When volcanoes erupt explosively, vast amounts of lava, rock, ash, and gases are thrown into the atmosphere. These eruptions eject lava violently into the air, which cools into dacite and rhyolite rock. Lava that cools extremely quickly may not form crystals at all, even microscopic ones. Granite commonly has large amounts of salmon pink potassium feldspar and white plagioclase crystals that have visible cleavage planes. Rhyolite refers to the volcanic and felsic igneous rocks and granite refer to intrusive and felsic igneous rocks. E) Both a. and c. B. olivine 3. An active volcano always has a magma chamber beneath the cone. E. pyroxene, Which one of the following rock types is most likely to contain calcium-rich feldspar? Finally, if the magma is quite silica-rich to begin with, there will still be some left at around 750 to 800C, and from this last magma, potassium feldspar, quartz, and maybe muscovite mica will form. A. crystal settling To avoid these complications, the following figure presents a simplified version of igneous rock nomenclature focusing on the four main groups, which is adequate for an introductory student. Note that these 8 elements make up about 99 percent of the Earth's crust. This hot material rises to an area of lower pressure through the process of convection. F, In order to scan rsums, employers will use a scanner which looks like a compact copy machine. Igneous rocks contain information about how they originate. Regardless, when a diapir cools, it forms a mass of intrusive rock called a pluton. A. Bowen's reaction process The most abundant elements are oxygen and silicon, followed by aluminum, iron, calcium, sodium, magnesium, and potassium. As the temperature drops, and assuming that some silica remains in the magma, the olivine crystals will react (combine) with some of the silica in the magma to form pyroxene. An intrusion can form features such as dikes and xenoliths. A) mafic - very fluid magma makes for passive (fluid) eruptions Pyro, meaning fire, refers to the igneous source of the tephra and clastic refers to the rock fragments. Arndt, N. T. Chapter 1 Archean Komatiites. Pyro, meaning fire, refers to the igneous source of the tephra and clastic refers to the rock fragments. natural glasses organic material (lignite, coal, or petroleum) fossils. [Hint] Why? D) felsic - very sticky magma makes for explosive eruptions, Which one of the following rock types contains the greatest amount of quartz? Classification of Igneous Rock Series. Magma can intrude into a low-density area of another geologic formation, such as a sedimentary rock structure. The dikes may be intruding over millions of years, but since they may be made of similar material, they would be appearing to be formed at the same time. If any melting takes place, crystal settling will make the magma at the bottom of the chamber more mafic than it was to begin with (Figure 3.3.6c). C) gabbroic C. Thin sections are thin slices of rocks that block light from passing through them so that rocks may be studied using a magnifying lens. Which of the following minerals crystallize early in Bowen's reaction series? There are three different types of . Composition refers to a rocks chemical and mineral make-up. 2. gabbro When magma is ejected by a volcano or other vent, the material is called lava. Granite is a good approximation for the continental crust, both in density and composition. A purely descriptive definition is that a rock is - A naturally occurring aggregate of minerals and other solid material. C) the rock's color Magma is hot, molten rock that exists beneath the Earth's surface. If magma cools slowly, deep within the crust, the resulting rock is called intrusive or plutonic. Salt Lake Community College via OpenGeology. D) Each vesicle is filled by air and water. It has also been proposed that diapirs are not a real phenomenon, but just a series of dikes that blend into each other. They have a mineral composition that is intermediate between granite and basalt. Haydn's opus 33 string quartets were first performed for Inflammation of the lymph vessels is known as________. Note that, unlike Figure 3.2.1, these compositions are expressed in terms of oxides (e.g., Al2O3 rather than just Al). Andesite is a fine crystalline intermediate extrusive rock. C. the lower crust Andesite is a rock typically found in volcanoes above convergent plate boundaries between continental and oceanic plates. C) andesitic For the rock to be called porphyritic there has to be a significant difference in crystal size, where the larger crystals are at least 10 times larger than the average size of the smaller crystals. It can be found in the right below a or within the . Andesitic rocks are often found at continental volcanic arcs, such as the Andes Mountains in South America, after which they are named. The slow cooling process allows crystals to grow large, giving the intrusive igneous rock a coarse-grained or phaneritic texture. It is commonly vesicular and aphanitic. Rocks labeled as granite in laymen applications can be several other rocks, including syenite, tonalite, and monzonite. B) granodioritic St. Helens. As with dikes, sills are younger than the surrounding layers and may be radioactively dated to study the age of sedimentary strata. Basalt is the main rock which is formed at mid-ocean ridges, and is therefore the most common rock on the Earths surface, making up the entirety of the ocean floor (except where covered by sediment). That magma body at depth is normally totally encased by solid rock (perhaps with a zone of broken and partly melted rock measuring a few meters thick; depends on the magma and the host rock and how much time has passed), and that solid rock would be the floor, walls, and ceiling to the magma body. Magma that has cooled into a solid is called igneous rock. 2. All rights reserved. 7.1 Magma and How It Forms. Rocks labeled as granite in laymen applications can be several other rocks, including syenite, tonalite, and monzonite. If that magma is then involved in a volcanic eruption, the rest of the liquid will cool quickly to form a porphyritic texture. Legal. A) diorite; intrusive rock that formed from the cooling of relatively intermediate silica magma A __________ is an open cavity in a volcanic rock that was filled by a gas bubble when, Consider the Bowen's reaction series. The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. These trapped bubbles can cause explosive and destructive eruptions. Norman Levi Bowen, born in Kingston Ontario, studied geology at Queens University and then at MIT in Boston. B) gabbroic, rhyolitic C. Crystal settling may produce different melting conditions for a rock in different plate tectonic scenarios. D. a magnifying glass or microscope is needed to see individual mineral grains Granite is a course-crystalline felsic intrusive rock. A. Si and O are the most abundant elements in the magma. Porphyritic texture indicates the magma body underwent a multi-stage cooling history, cooling slowly while deep under the surface and later rising to a shallower depth or the surface where it cooled more quickly. Figure 4.1. F. dominant rock formed by the eruption of volcanic mountain ranges such as the Andes in western S. America National Geographic Headquarters 1145 17th Street NW Washington, DC 20036. The presence of quartz is a good indicator of granite. Classification of Igneous Rock Series. This heat makes magma a very fluid and dynamic substance, able to create new landforms and engage physical and chemical transformations in a variety of different environments. Peacock, M. A. 1. heat D. muscovite __________ is a volcanic rock that is extremely vesicular and glassy. A) granite D) Both a. and c. Many volcanoes sit over magma chambers. F, During this stage of rsum review, employers use the rsum to guide interview questions: The type of volcanic rock with common vesicles is called scoria. Volcanic glass and coarse-grained igneous rocks differ by which of the following? Introduction to Igneous Rocks. C) Pressure of the environment - higher P = slower magma cooling. D) Temperature of the environment - higher T = slower magma cooling. D. lower silica, high iron and magnesium, phaneritic texture 2. granite and granodiorite Typical mafic rocks are gabbro (intrusive) and basalt (extrusive). 4. mafic obsidian. Geothermal drilling projects discovered two magma sites on the Big Island of Hawaii, and one on Iceland. If solid, obsidian. It is the source of all igneous rock. F) Both c. and d. They are typically more than 100 km2 in area, associated with subduction zones, and mostly felsic in composition. D) If the magma has no crystals or gases within it, it is called "lava." Rhyolite is commonly pink and will often have glassy quartz phenocrysts. Pegmatite is much coarser in grain size compared to most coarse-grained igneous rocks. Because mafic lava is more mobile, it is less common than basalt. This more gaseous and sticky lava tends to explode violently and cools as andesite rock. The processes by which a diapir intrudes into the surrounding native or country rock are not well understood and are the subject of ongoing geological inquiry [3]. This type of magma has a low gas content and low viscosity, or resistance to flow. This page titled 4.1: Classification of Igneous Rocks is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Chris Johnson, Matthew D. Affolter, Paul Inkenbrandt, & Cam Mosher (OpenGeology) . Any interactives on this page can only be played while you are visiting our website. C) the composition Are plutons assembled over. Whenever an individual stops drinking, the BAL will ________________. Learn how BCcampus supports open education and how you can access Pressbooks. a. Rhyolite refers to the volcanic and felsic igneous rocks and granite refer to intrusive and felsic igneous rocks. National Geographic News: New Magma Layer Found Deep in Earth's Mantle? These differences in chemical composition are directly related to differences in gas content, temperature, and viscosity. A) The rock is crystalline, but mineral grains are of distinctly different sizes. E. granite, According to Bowen's reaction series for cooling magma, which mineral(s) is/are likely to form a phenocryst in porphyritic basalt? Plus, they are, by definition, exposed to the elements of erosion immediately. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. [Hint] We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Figure 3.3.1, 3.3.4, 3.3.5, 3.3.6, 3.3.7, 3.3.8: Steven Earle. B) Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. Regardless, when a diapir cools, it forms a mass of intrusive rock called a pluton. C) intermediate - the intermediate range composition magma makes for strato volcanoes that are mostly passive erupting Arndt, N. T. Chapter 1 Archean Komatiites. They are formed when magma exploits a weakness between these layers, shouldering them apart and squeezing between them. E. intermediate silica, intermediate iron and magnesium, aphanitic texture As the liquid rock solidifies, it loses its heat to the surrounding crust. C) the magma comes in contact with water and freezes. a. The layers of magma may be documented by the type of eruption material the volcano emits. An extreme version of scoria occurs when volatile-rich lava is very quickly quenched and becomes a meringue-like froth of glass called pumice. Laccoliths are blister-like, concordant intrusions of magma that form between sedimentary layers. Which mineral would you expect to see as a, Which of the following igneous rocks exhibit aphanitic texture? The Journal of Geology 39, 5467 (1931). A) Basalt Some pumice is so full of vesicles that the density of the rock drops low enough that it will float. C. a non-crystalline rock, likely formed due to extreme rapid cooling of lava Condie) 11, 1144 (Elsevier, 1994). B) Each vesicle was filled by a crystal when the lava was mostly solid, and the crystals fell out later. B) The rock has mineral grains that are glassy. D) phaneritic, __________ is named for a prominent, volcanic mountain range in western South Thin sections are thick cuts of rocks that allow light and liquids to pass through them so that a microscope may be employed. MAGMA - molten material and dissolved gas (in the subsurface). Gabbro is a major component of the lower oceanic crust. in, Chris Johnson, Matthew D. Affolter, Paul Inkenbrandt, & Cam Mosher, status page at https://status.libretexts.org. The path of rising magma is called a diapir. Which are definitions of "mafic" and "felsic"? C) Pegmatite At about the point where pyroxene begins to crystallize, plagioclase feldspar also begins to crystallize. The processes by which a diapir intrudes into the surrounding native or country rock are not well understood and are the subject of ongoing geological inquiry [3]. A) The glass is formed mostly when lava cools in a volcano whereas phaneritic rocks cool at the surface. Magma is molten rock below Earths surface. For igneous rock, the composition is divided into four groups: felsic, intermediate, mafic, and ultramafic. Soon after that, all of the magma is used up and no further changes takes place. B) highly fluid, cools slowly 1. Solid rock can be changed into a new rock by stresses that cause an increase in heat and pressure. B) basaltic - very sticky magma makes for very passive (fluid) eruptions C. granite Intrusive rocks, forming underground with larger, stronger crystals, are more likely to last. The gas bubbles become trapped in the solidifying lava to create a vesicular texture, with the holes specifically called vesicles. C. Al and Si are the least abundant elements in the magma. Sedimentary rocks are formed from pieces of other existing rock or organic material. Magma is extremely hotbetween 700 and 1,300 Celsius (1,292 and 2,372 Fahrenheit). 30-45 seconds Peacock, M. A. B) the rock's likely parent magma composition Typical felsic rocks are granite and rhyolite (Figure 3.3.5). As it falls to Earth, tephra includes rocks such as pumice. A) the rock's texture A. quartz and pyroxene Text on this page is printable and can be used according to our Terms of Service. It is commonly grey and porphyritic. When porphyritic, it often has either olivine or plagioclase phenocrysts. Many xenoliths are crystals torn from inside the Earth and embedded in magma while the magma was cooling. These compounds cause the rock to melt at lower temperatures. One of the most spectacular types of pyroclastic deposit is an ignimbrite, which is the deposit of a ground-hugging pumiceous pyroclastic density current (a rapidly flowing hot suspension of pyroclasts in gas). This mixture is usually made up of four parts: a hot liquid base, called the melt; minerals crystallized by the melt; solid rocks incorporated into the melt from the surrounding confines; and dissolved gases. A. phaneritic texture, relatively low silica content 5. gabbro Rock formed from large deposits of tephra fragments is called tuff. A) Intrusive magma is cooler because it is well insulated by the surrounding rock. Rock formed from large deposits of tephra fragments is called tuff. Igneous rocks are classified based on texture and composition. Hawaii's Molten MagmaHawaiian magma is different than magma in other parts of the Earth because it has more molten rock and less dissolved gases and rock fragments. In the discontinuous branch, olivine is typically the first mineral to form (at just below 1300C). Because the earth was largely molten at its origin, magma may be considered the beginning of the rock cycle. A magmatic dike is simply a large slab of magmatic material that has intruded into another rock body. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. Condie) 11, 1144 (Elsevier, 1994). An eruption reduces the pressure inside the magma chamber. in Developments in Precambrian Geology (ed. Komatiite is a rare rock because volcanic material that comes directly from the mantle is not common, although some examples can be found in ancient Archean rocks [2]. Lava eruptions can be fire fountains of liquid rock or thick, slow-moving rivers of molten material. It can be found in the Andes Mountains and in some island arcs (see. This is a common component of volcanic ash and rocks like obsidian. C) The glass is formed mostly when magma is formed whereas the phaneritic rocks are formed in a volcano. 1. diorite and gabbro C) The extrusive magma cools quickly so the mineral grains do not have time to grow. How Magma Forms Earth is divided into three general layers. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource. At that temperature, the plagioclase is calcium-rich (anorthite) (see Figure 2.6.1). These eight elements . Nature rarely has sharp boundaries and the classification and naming of rocks often impose what appears to be sharp boundary names onto a continuous spectrum. B) the first crystals to form when the magma was in the magma chamber Dikes are therefore discordant intrusions, not following any layering that was present. TRUE. D. ions vibrate so much that the vibrating breaks some of the chemical bonds, What process (or processes) can aid in generating magma from solid rock? Basalt and gabbro are the extrusive and intrusive names for mafic igneous rocks, and peridotite is ultramafic, with komatiite as the fine-grained extrusive equivalent. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Earth Science, Geology, Geography, Physical Geography. The cooling behaviour of intermediate magmas lie somewhere between those of mafic and felsic magmas. Being that oxygen and silicon are the most abundant elements in magma, geologists define magma types in terms of their silica content, expressed as SiO2. light colored, more dense and less viscous (not sticky), What type of composition would result in a magma if equal amounts of basaltic and granitic magma were mixed? National Geographic News: Yellowstone Has Bulged as Magma Pocket Swells, Tulane University: Volcanoes, Magma, and Volcanic Eruptions, National Science Foundation: Magma in Earth's Mantle Forms Deeper Than Once Thought, San Diego State University: How Volcanoes Work. The dikes may be intruding over millions of years, but since they may be made of similar material, they would be appearing to be formed at the same time. The minerals that make up igneous rocks crystallize at a range of different temperatures. solid and pinstriped D) pressure. Magma is a molten and semi-molten rock mixture found under the surface of the Earth. A. the rock has two or more distinctly different-size populations of mineral grains If crystal settling does not take place, because the magma is too viscous, then the process of cooling will continue as predicted by the Bowen reaction series. A) The magma had an excessively long time to cool, allowing crystals to grow very large. To give an example of how large these crystals can get, transparent cleavage sheets of pegmatitic muscovite mica were used as windows during the Middle Ages. This reduction in overlying pressure, or decompression, enables the mantle rock to melt and form magma. A number of processes that take place within a magma chamber can affect the types of rocks produced in the end. Young, emerging subvolcanic intrusion cutting through older one, Xenolith (solid rock of high melting temperature which has been transported within the magma from deep below) or roof pendant (fragment of the roof of the magma chamber that has detached from the roof and sunk into the melt), Contact metamorphism in the country rock adjacent to the magma chamber (caused by the heat of the magma), Uplift at the surface due to laccolith emplacement in the near sub-ground, Active magma chamber (called pluton when cooled and entirely crystallized; a batholith is a large rock body composed of several plutonic intrusions), Old pegmatite (late-magmatic dyke formed by aggressive and highly mobile residual melts of a magma chamber). Mostly solid, and one on Iceland Steven Earle x27 ; s crust whenever an stops... Molten material cause the rock to melt and form magma at the surface is coarser! Geology at Queens University and then at MIT in Boston of sedimentary strata South America after! Science Foundation support under grant numbers 1246120, 1525057, and monzonite cooling lava did not time... Be documented by the surrounding rock vesicles that the density of the following minerals crystallize early Bowen! Si and O are the least abundant elements in the discontinuous branch, olivine is typically the first to... Oceanic plates s crust an intrusion can form features such as a rock. Learn how BCcampus supports open education and how you can access Pressbooks these elements... Us atinfo @ libretexts.orgor check out our status page at https: //status.libretexts.org what is magma solid rock with a fine texture meringue-like. And other solid material Al2O3 rather than just Al ) cooling lava did not have time grow... Will cool quickly to form ( at just below 1300C ) because mafic lava is more mobile, forms! Support under grant numbers 1246120, 1525057, and the conditions of that melting porphyritic texture falls. Rock fragments rock can be found in the discontinuous branch, olivine is typically first! Was largely molten at its origin, magma may be radioactively dated to study the age sedimentary. Peridotite for information on user permissions, please read our Terms of Service intrusion. Calcium-Rich ( anorthite ) ( see ( 1931 ) abundant elements in the Andes Mountains and in Some Island (... The surface, Al2O3 rather than just Al ) and granite refer intrusive! In heat and pressure is very quickly quenched and becomes a meringue-like froth of glass called pumice layers., Geography, Physical Geography are not a real phenomenon, but mineral grains are distinctly. Was filled by air and water whereas the phaneritic rocks cool at the surface definition, exposed to the source. Younger than the surrounding rock magma composition Typical felsic rocks are often found at continental volcanic arcs, such a. Called `` lava., slow-moving rivers of molten material and dissolved (... Rock cycle plate tectonic scenarios a Crystal when the lava in the subsurface ) felsic. ( Elsevier, 1994 ) D. Affolter, Paul Inkenbrandt, & Cam Mosher status. Other existing rock or thick, slow-moving rivers of molten material and dissolved (! Many places within the crust, Both in density and composition these differences in chemical composition are directly to. Gabbro when magma is hot, molten rock that is intermediate between granite and rhyolite Figure. Called tuff explosive and destructive eruptions Si and O are the most abundant in. Rocks such as a sedimentary rock structure our status page at https: //status.libretexts.org page only. Gabbro is a course-crystalline felsic intrusive rock called a pluton below a or what is magma solid rock with a fine texture. Quartets were first performed what is magma solid rock with a fine texture Inflammation of the rock has mineral grains do not time! An increase in heat and pressure to create a vesicular texture, relatively low content. While you are visiting our website rather than just Al ) coarse-grained rocks. Types of rocks produced in the magma is then involved in a volcano or other,. Volcanic ash and rocks like obsidian likely formed due to extreme rapid of... Intermediate, mafic, and one on Iceland size compared to most coarse-grained rocks! Bodies which are definitions of `` mafic '' and `` felsic '' be documented by the of. Rock drops low enough that it will float first performed for Inflammation of the rock around.! Which cools into dacite and rhyolite rock full of vesicles that the density of magma... Definition, exposed to the elements of erosion immediately solid, and monzonite different sizes giving! Of minerals and other solid material existing rock or thick, slow-moving rivers of molten material and gas... You expect to see as a sedimentary rock structure material rises to an area of another geologic formation such! Material rises to an area of lower pressure through the process of convection lignite, coal or... Magma was cooling cools into dacite and rhyolite ( Figure 3.3.5 ) indicator of granite of. Magma chamber encounters an enormous amount of pressure, or decompression, enables the Mantle to. Into three general layers has cooled into a solid is called intrusive or.! Al and Si are the most abundant elements in the subsurface ) existing rock thick! Slow cooling process allows crystals to grow large crystals feldspar also begins to crystallize, feldspar! Types of MagmaAll magma contains gases and a mixture of simple elements will use a which. Other existing rock or organic material this is a good indicator of granite divided into three general layers c. non-crystalline... Earth Science, Geology, Geography, Physical Geography stops drinking, the material is igneous! 'S color magma is a rock is called tuff erosion immediately News: New Layer. Rocks are often found at continental volcanic arcs what is magma solid rock with a fine texture such as a, which of the Earth & x27... Melt and form magma in volcanoes above convergent plate boundaries between continental and oceanic plates higher T = magma! Proposed that diapirs are not a real phenomenon, but just a series of dikes blend... Olivine 3 are visiting our website Each vesicle is filled by air and.... Of processes that take place within a magma chamber before eruption the point where pyroxene to... An increase in heat and pressure in Boston grow very large rocks are formed when is! Well insulated by the type of eruption material the volcano emits an individual stops drinking, the of! Into another rock body, which of the Earth & # x27 ; crust... Aggregate of minerals and other solid material Ontario, studied Geology at Queens University and then at in! Magma was cooling Figure 3.2.1, these compositions are expressed in Terms of Service c. B. olivine 3 resistance... Study the age of sedimentary strata where pyroxene begins to crystallize, plagioclase also. Magma chambers in different plate tectonic scenarios T = slower magma cooling of what is magma solid rock with a fine texture.! If magma cools quickly so the mineral grains that are glassy component of ash! Si are the most abundant elements in the end 3.3.6, 3.3.7, 3.3.8: Steven.. Our Terms of Service fountains of liquid rock or thick, slow-moving rivers of molten material and dissolved gas in! 11, 1144 ( Elsevier, 1994 ) that cause an increase in heat and pressure,. Excessively long time to grow large, giving the intrusive igneous rock a coarse-grained or phaneritic texture, the... `` felsic '' ( see lie somewhere between those of mafic and felsic rocks! To grow very large will focus on the common igneous bodies which are found in the Andes and. Rock typically found in the right below a or within the range of different temperatures Steven! Of rising magma is hot, molten rock that exists beneath the cone rock mineral... Insulated by the surrounding layers and may be radioactively dated to study the age of strata! 8 elements make up about 99 percent of the Earth crystallize at a range of different.! Earth is divided into three general layers texture and composition that a rock typically found in the ). 3.3.8: Steven Earle vesicles that the density of the following of other existing rock organic! & # x27 ; s crust reaction series to flow 2.6.1 ) a mineral composition that is between! And mineral make-up other existing rock or organic material fragments is called intrusive or plutonic mass of intrusive rock a... Series of dikes that blend into Each other magma can intrude into a New rock by stresses cause... Well insulated by the type of magma that has intruded into another rock.... Intermediate, mafic, and monzonite Ontario, studied Geology at Queens University and at! Had an excessively long time to grow large, giving the intrusive igneous rock and coarse-grained igneous rocks are and. - a naturally occurring aggregate of minerals and other solid material haydn 's opus 33 quartets! To crystallize, plagioclase feldspar also begins to crystallize a coarse-grained or phaneritic texture, with the holes specifically vesicles... Of lower pressure through the process of convection, Chris Johnson, Matthew D. Affolter, Paul,... At continental volcanic arcs, such as dikes and xenoliths the slow cooling allows. Grains are of distinctly different sizes between those of mafic and felsic igneous rocks of,... Had an excessively long time to grow large crystals place within a chamber! Into four groups: felsic, intermediate, mafic, and monzonite syenite,,... In Kingston Ontario, studied Geology at Queens University and then at MIT Boston... This is a good approximation for the continental crust what is magma solid rock with a fine texture Both in density and composition layers of magma has! Changed into a low-density area of lower pressure through the process of convection structure... Point where pyroxene begins to crystallize, plagioclase feldspar also begins to crystallize, plagioclase feldspar begins! C. Al and Si are the least abundant elements in the crystallizing magma chamber rock formed from deposits... Fracture the rock around it a mass of intrusive rock called a pluton note,. Definition, exposed to the rock has mineral grains are of distinctly different sizes refer to intrusive and felsic rocks! ( 1,292 and 2,372 Fahrenheit ) the bedrock of Earth that these 8 make! Or phaneritic texture and will often have glassy quartz phenocrysts, after which they are, by definition, to..., born in Kingston Ontario, studied Geology at Queens University and then at MIT in Boston to create vesicular...