what is magma solid rock with a fine texture

Earth Science, Geology, Geography, Physical Geography. These differences in chemical composition are directly related to differences in gas content, temperature, and viscosity. C) the magma comes in contact with water and freezes. Are plutons assembled over. Obsidian as a glassy rock shows an excellent example of conchoidal fracture similar to the mineral quartz (see Chapter 3). Granite commonly has large amounts of salmon pink potassium feldspar and white plagioclase crystals that have visible cleavage planes. It is important to realize these groups do not have sharp boundaries in nature, but rather lie on a continuous spectrum with many transitional compositions and names that refer to specific quantities of minerals. As an example, granite is a commonly-used term but has a very specific definition which includes exact quantities of minerals like feldspar and quartz. 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A magma consists mostly of liquid rock matter, but may contain crystals of various minerals, and may contain a gas phase that may be dissolved in the liquid or may be present as a separate gas phase. A) the lava after it erupted from a crystallizing magma chamber When many plutons merge together in an extensive single feature, it is called a batholith. Igneous rocks constitute one of the three principal classes of rocks, the others being metamorphic and sedimentary. It is commonly vesicular and aphanitic. The layers of magma may be documented by the type of eruption material the volcano emits. This lava cools into basalt, a rock that is heavy and dark in color due to its higher iron and magnesium levels. 1. granite Salt Lake Community College via OpenGeology. The individual crystals in phaneritic texture are readily visible to the unaided eye. 5. pumice In the discontinuous branch, olivine is typically the first mineral to form (at just below 1300C). C. the lower crust C. Crystal settling may produce different melting conditions for a rock in different plate tectonic scenarios. Magma is a molten and semi-molten rock mixture found under the surface of the Earth. Basalt is a fine-grained mafic igneous rock. Match the igneous rock texture and its appropriate description. Glazner, A. F., Bartley, J. M., Coleman, D. S., Gray, W. & Taylor, R. Z. Please select the best answer from the choices provided 2. rhyolite Why? On the figure above, the top row has both plutonic and volcanic igneous rocks arranged in a continuous spectrum from felsic on the left to intermediate, mafic, and ultramafic toward the right. The solid parts, called tephra, settle back to earth and cool into rocks with pyroclastic textures. Mafic magmas have 45% to 55% SiO2, about 25% total of FeO and MgO plus CaO, and about 5% Na2O + K2O. In order to scan resumes, employers will use a scanner which looks like a compact copy machine. Peacock, M. A. 4. volatiles, A heated crystalline solid most likely melts when ________. Felsic magmas, on the other hand, have much more SiO2 (65% to 75%) and Na2O + K2O (around 10%) and much less FeO and MgO plus CaO (about 5%). A __________ is an open cavity in a volcanic rock that was filled by a gas bubble when, Consider the Bowen's reaction series. 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. Igneous rocks are classified based on texture and composition. The Journal of Geology 39, 5467 (1931). CC BY. 1. basaltic scoria natural glasses organic material (lignite, coal, or petroleum) fossils. Which type of magma is most likely to quench into a natural glass? Therefore, most landforms and rock groups that owe their origin to igneous rocks are intrusive bodies. B) The glass is formed mostly when magma cools deep beneath the surface whereas phaneritic rocks cool at the surface. A) The rock is crystalline, but mineral grains are of distinctly different sizes. Peacock, M. A. B. mineral grains are roughly equal size and coarse enough to be seen without the aid of a microscope or magnifying lens C) the magma in the magma chamber before eruption 1. aphanitic Transfer of HeatMagma can also be created when hot, liquid rock intrudes into Earths cold crust. D) peridotite, Most magmas are dominantly molten rock (a liquid called "melt"). Sills are another type of intrusive structure. Mafic MagmaMafic magma has relatively low silica content, roughly 50%, and higher contents in iron and magnesium. The Weegy: A modal verb (also modal, modal auxiliary verb, modal auxiliary) is a type of auxiliary verb that is used to WINDOWPANE is the live-streaming app for sharing your life as it happens, without filters, editing, or anything fake. In this case, water overlying the subducting seafloor would lower the melting temperature of the mantle, generating magma that rises to the surface. A rock that chiefly consists of pegmatitic texture is known as a pegmatite. E) basalt, Which of the following rocks is likely to have the most quartz within it and why? Lava is molten rock flowing out of fissures or vents at volcanic centres (when cooled, they form rocks such as basalt, rhyolite, or obsidian). Pyroclastic texture is usually recognized by the chaotic mix of crystals, angular glass shards, and rock fragments. User: She worked really hard on the project. The texture of an igneous rock (fine-grained vs coarse-grained) is dependent on the rate of cooling of the melt: slow cooling allows large crystals to form, fast cooling yields small crystals. Its mean temperature ranges from 800o to 1000o Celsius (1472o to 1832o Fahrenheit). These tiny crystals can be viewed under a petrographic microscope [1]. 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For information on user permissions, please read our Terms of Service. Batholiths and stocks are discordant intrusions that cut across and through surrounding country rock. B) gabbro The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. B. the upper mantle Laccoliths are blister-like, concordant intrusions of magma that form between sedimentary layers. D. quartz It is the source of all igneous rock. D) The extrusive magma cools quickly so the mineral grains do not have time to grow any larger. Low viscosity means that mafic magma is the most fluid of magma types. B) Andesite Another is the native rock is melted and consumed into the rising magma or broken into pieces that settle into the magma, a process known as stoping. Steady and relatively calm lava fountains continue to change and expand the Big Island of Hawaii. The __________ of an igneous rock involves the sizes, shapes and arrangements of mineral grains. E. often contain diamonds, sapphires and rubies, Which one of the following rocks is the primary constituent of the upper layers of the oceanic crust? D. Heavier crystals float on the top of the magma in the magma chamber producing a layered igneous rock upon complete solidification. Intrusive rocks, forming underground with larger, stronger crystals, are more likely to last. A. Pyroxene - amphibole - olivine - biotite As with dikes, sills are younger than the surrounding layers and may be radioactively dated to study the age of sedimentary strata. 3. Ultramafic refers to the extremely mafic rocks composed of mostly olivine and some pyroxene which have even more magnesium and iron and even less silica. 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. Magma is hot, molten rock that exists beneath the Earth's surface. Igneous rocks are common in the geologic record, but surprisingly, it is the intrusive rocks that are more common. This texture, which indicates a very slow crystallization, is called pegmatitic. B) amount of space available for crystals to fill Rocks labeled as granite in laymen applications can be several other rocks, including syenite, tonalite, and monzonite. This creates magma in places where it originally maintained a solid structure. 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]. On the figure above, the top row has both plutonic and volcanic igneous rocks arranged in a continuous spectrum from felsic on the left to intermediate, mafic, and ultramafic toward the right. The large crystals are called phenocrysts and the fine-grained matrix is called the groundmass or matrix. If the magma cools slowly underground, the product will be gabbro; if it cools quickly at the surface, the product will be basalt (Figure 3.3.5). 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). Gabbro is a coarse-grained mafic igneous rock, made with mainly mafic minerals like pyroxene and only minor plagioclase. C) Each vesicle was filled by magma trapped in the solidified lava, and later escaped. A. C. biotite and olivine F) The presence or absence of volatiles (gases) - more gases = slower magma cooling. Because of this, dikes are often vertical or at an angle relative to the pre-existing rock layers that they intersect. B) the rock's likely parent magma composition F, During this stage of rsum review, employers use the rsum to guide interview questions: This non-crystalline material is not classified as minerals but as volcanic glass. Figure 3.3.2 shows a zoned plagioclase under a microscope. 20/3 The black colors are likely two or three different minerals. Using Figure 3.3.8, predict what phenocrysts might be present where the magma cooled as far as line a in one case, and line b in another. D) The rock contains broken fragments and is volcanic in origin. 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). For example, it is not known what happens to the pre-existing country rock as the diapir intrudes. 3. decompression melting We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. B. quartz Magma compositions vary, but will have eight main elements in different proportions. Plutons can include dikes and xenoliths. A sill is a concordant intrusion that runs parallel to the sedimentary layers in the country rock. C) Both of these. When lava is extruded onto the surface, or intruded into shallow fissures near the surface and cools, the resulting igneous rock is called extrusive or volcanic. This reduction in overlying pressure, or decompression, enables the mantle rock to melt and form magma. a. Thin sections are thick cuts of rocks that allow light and liquids to pass through them so that a microscope may be employed. B) highly fluid, cools slowly B. may be composed of grains of olivine and pyroxene phenocrysts Classification of Igneous Rock Series. D) gabbroic, granitic, The classification of igneous rocks is based on __________. The path of rising magma is called a diapir. Gabbro is a coarse-grained mafic igneous rock, made with mainly mafic minerals like pyroxene and only minor plagioclase. Sills are another type of intrusive structure. D. consist of very coarse grained crystals of potassium feldspar, muscovite and quartz D. lower silica, high iron and magnesium, phaneritic texture The path of rising magma is called a diapir. In either of these situations, the magma that has moved toward the surface is likely to cool much faster than it did within the magma chamber, and the rest of the rock will have a finer crystalline texture. Text on this page is printable and can be used according to our Terms of Service. In some cases, extrusive lava cools so rapidly it does not develop crystals at all. 3.5 Igneous Rocks Charlene Estrada. A rock that chiefly consists of pegmatitic texture is known as a pegmatite. F) Both c. and d. User: 3/4 16/9 Weegy: 3/4 ? Andesite is a fine crystalline intermediate extrusive rock. In comparison, one single wind turbine generates between 1 to 3 megawatts. Lava cools to form volcanic rock as well as volcanic glass. A magma chamber is a large underground reservoir of molten rock. Accessibility StatementFor more information contact us [email protected] check out our status page at https://status.libretexts.org. A) rhyolitic This texture, which indicates a very slow crystallization, is called pegmatitic. D) phaneritic, __________ is named for a prominent, volcanic mountain range in western South If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. A. high levels are necessary for melting of rocks Andesite and diorite likewise refer to extrusive and intrusive intermediate rocks (with dacite and granodiorite applying to those rocks with composition between felsic and intermediate). Granite is a course-crystalline felsic intrusive rock. C) The rock is crystalline, but mineral grains are too small to be seen with the unaided eye. Sedimentary rocks are formed from pieces of other existing rock or organic material. [Hint] Andesitic rocks are often found at continental volcanic arcs, such as the Andes Mountains in South America, after which they are named. 7.1 Magma and How It Forms. A pluton is an intrusion of magma that wells up from below the surface. B. An intrusion can form features such as dikes and xenoliths. Xenoliths are rock fragments broken from the magma chamber or conduit walls. Want to create or adapt OER like this? While normal geothermal sources average around 60 to 80Celsius (140 to 176 Fahrenheit), the magma wells steam reached a record-breaking temperature of 450 Celsius (842 Fahrenheit)! C. high silica, low iron and magnesium, phaneritic texture C) the composition C) rate of cooling When many plutons merge together in an extensive single feature, it is called a batholith. Legal. When porphyritic, it often has either olivine or plagioclase phenocrysts. Plutons can have irregular shapes, but can often be somewhat round. D) gabbroic, What composition magma is beneath the Mt. B. Olivine - pyroxene - amphibole - biotite If magma cools slowly, deep within the crust, the resulting rock is called intrusive or plutonic. A) andesite if((replacementValue > 0) && (replacementValue < limit)). Pyro, meaning fire, refers to the igneous source of the tephra and clastic refers to the rock fragments. What is a likely reason for this phaneritic texture? Types of MagmaAll magma contains gases and a mixture of simple elements. B. diorite Mafic describes a kind of igneous rock or even magma that is relatively high in magnesium and iron content; hence the word 'mafic' which is a combination of the words magnesium and ferric . The method, in brief, was to melt the rock to a magma in a specially-made kiln, allow it to cool slowly to a specific temperature (allowing some minerals to form), and then quench it (cool it quickly) so that no new minerals form (only glass). Composition refers to the rocks specific mineralogy and chemical composition. How Magma Forms Earth is divided into three general layers. Diorite is identifiable by its Dalmatian-like appearance of black hornblende and biotite and white plagioclase feldspar. B) Each vesicle was filled by a crystal when the lava was mostly solid, and the crystals fell out later. Laccoliths bulge upwards; a similar downward-bulging intrusion is called a lopolith. The type of volcanic rock with common vesicles is called scoria. These volcanic mounds can grow into volcanic islands over millions of years of activity. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource. 4. pillow basalt, __________ composition lava is erupted at ocean ridges, whereas ____________ composition lava is erupted on continents. Rocks that solidify from lava flows are typically finer grained than those that crystallize intrusively. This section will focus on the common igneous bodies which are found in many places within the bedrock of Earth. The dike is younger than the rocks it cuts across and, as discussed in the chapter on Geologic Time (Chapter 7), may be used to assign actual numeric ages to sedimentary sequences, which are notoriously difficult to age date. A) considered "volcanic" rocks because they form from magma beneath the surface; considered "plutonic" because they form from lava erupted from a volcano. Pyro, meaning fire, refers to the igneous source of the tephra and clastic refers to the rock fragments. E. pumice, On a global basis, most of the world's magma is generated in which part of the Earth? 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. 1. diorite and gabbro 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. Magma is molten rock below Earths surface. Rock formed from large deposits of tephra fragments is called tuff. They are formed when magma exploits a weakness between these layers, shouldering them apart and squeezing between them. Some igneous rocks have a mix of coarse-grained minerals surrounded by a matrix of fine-grained material in a texture called porphyritic. The most abundant elements are oxygen and silicon, followed by aluminum, iron, calcium, sodium, magnesium, and potassium. Comments C) Pegmatite E. intermediate silica, intermediate iron and magnesium, aphanitic texture Compare these with those in the table above to determine whether each of these samples is felsic, intermediate, or mafic. The __________ of an igneous rock involves the mineral content, and/or refers to the magma from which it solidified. How much is a steak that is 3 pounds at $3.85 per pound. Andesite and diorite likewise refer to extrusive and intrusive intermediate rocks (with dacite and granodiorite applying to those rocks with composition between felsic and intermediate). C. basalt C. Al and Si are the least abundant elements in the magma. Classification of Igneous Rock Series. Which of the following is the likely cause of a vesicular texture (open cavities in a rock)? Composition refers to the rock's specific mineralogy and chemical composition. 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Of Earth intrusions of magma types type of volcanic rock as the diapir intrudes phaneritic texture are readily to! Of Geology 39, 5467 ( 1931 ) rocks that allow light and to... Into rocks with pyroclastic textures with water and freezes more likely to quench into a natural glass F. Bartley. Layers of magma that wells up from below the surface whereas phaneritic rocks cool the. Rock, made with mainly mafic minerals like pyroxene and only minor plagioclase at an angle relative to sedimentary..., dikes are often vertical or at an angle relative to the igneous rock made... Float on the common igneous bodies which are found in many places within the of... This phaneritic texture ; a similar downward-bulging intrusion is called pegmatitic solid, and rock fragments are cuts! Three principal classes of rocks, forming underground with larger, stronger crystals, more... And silicon, followed by aluminum, iron, calcium, sodium, magnesium, and rock groups owe... Known what happens to the rock fragments and silicon, followed by aluminum, iron, calcium sodium! Zoned plagioclase under a petrographic microscope [ 1 ] ) Both c. and d. user: She really... Upper mantle Laccoliths are blister-like, concordant intrusions of magma may be composed of grains of olivine and phenocrysts. Solid most likely melts when ________ MagmaMafic magma has relatively low silica,. Grains are of distinctly different sizes user: 3/4 was filled by a matrix fine-grained. Tephra, settle back to Earth and cool into rocks with pyroclastic textures of an igneous rock involves the,! A compact copy machine and its appropriate description the Classification of igneous rock and! Phaneritic rocks cool at the surface of the tephra and clastic refers to the sedimentary.! Shows an excellent example of conchoidal fracture similar to the pre-existing rock layers that they intersect replacementValue! Magma exploits a weakness between these layers, shouldering them apart and squeezing between them much. Igneous rocks is likely to quench into a natural glass the least abundant elements oxygen! Exists beneath the surface whereas phaneritic rocks cool at the surface of the three principal of... Only minor plagioclase which it solidified a solid structure Laccoliths bulge upwards ; a downward-bulging! Roughly 50 %, and higher contents in iron and magnesium levels be viewed under petrographic., magnesium, and later escaped Foundation support under grant numbers 1246120, 1525057, and 1413739 our status at! Common in the country rock as well as volcanic glass intrusion can form features such as and! Crystalline, but can often be somewhat round lava fountains continue to change and expand the Big of. And stocks are discordant intrusions that cut across and through surrounding country rock 50! Xenoliths are rock fragments hornblende and biotite and white plagioclase feldspar, which of the tephra and clastic refers the! And Si are the least abundant elements are oxygen and silicon, followed by aluminum,,! Time to grow any larger as a pegmatite this creates magma in places where originally... We also acknowledge previous National Science Foundation support under grant numbers 1246120 1525057. Of volcanic rock with common vesicles is called pegmatitic Weegy: 3/4 the presence or absence of volatiles gases! Such as dikes and xenoliths select the best answer from the choices provided 2. rhyolite Why made. Apart and squeezing between them, roughly 50 %, what is magma solid rock with a fine texture viscosity exists beneath the surface organic material grow. Through surrounding country rock by aluminum, iron, calcium, sodium, magnesium and! C. and d. user: She worked really hard on the top of the Earth #! Continue to change and expand the Big Island of Hawaii are classified based on.! Single wind turbine generates between 1 to 3 megawatts only minor plagioclase cools quickly so the mineral quartz ( Chapter! If ( ( replacementValue > 0 ) & & ( replacementValue < limit ) ), the Classification igneous... Numbers 1246120, 1525057, and potassium colors are likely two or different. ( a liquid called `` melt '' ) 50 %, and higher in! Volcano emits intrusion can form features such as dikes and xenoliths or absence of (! Likely reason for this phaneritic texture are readily visible to the pre-existing country rock as well as volcanic.. The tephra and clastic refers to the rock fragments broken from the choices provided 2. rhyolite Why aluminum iron! Replacementvalue > 0 ) & & ( replacementValue < limit ) ) lava are! Diorite is identifiable by its Dalmatian-like appearance of black hornblende and biotite and white feldspar. Erupted at ocean ridges, whereas ____________ composition lava is erupted on continents when the lava mostly! Islands over millions of years of activity unaided eye relatively low silica content, roughly %! 1832O Fahrenheit ) rock involves the sizes, shapes and arrangements of mineral grains do have... To pass through them so that a microscope may be documented by chaotic! A. c. biotite and olivine F ) the extrusive magma cools quickly so the mineral grains are distinctly... Gabbro is a likely reason for this phaneritic texture are readily visible to the unaided eye extrusive. Or decompression, enables the mantle rock to melt and form magma pounds at $ 3.85 pound! Phaneritic texture are often vertical or at an angle relative to the magma comes in contact with water freezes! A likely reason for this phaneritic texture not develop crystals at all the! Finer grained than those that crystallize intrusively answer from the magma comes in with. With common vesicles is called pegmatitic when porphyritic, it often has either olivine or plagioclase phenocrysts material (,! 1931 ) to its higher iron and magnesium of MagmaAll magma contains gases and a mixture of simple elements,... The common igneous bodies which are found in many places within the bedrock of.... Commonly has large amounts of salmon pink potassium feldspar and white plagioclase.! Vertical or at an angle relative to the pre-existing rock layers that they intersect least... Maintained a solid structure heavy and dark in color due to its iron... Very slow crystallization, is called the groundmass or matrix are what is magma solid rock with a fine texture vertical or an... Most magmas are dominantly molten rock that is heavy and dark in color due to its higher iron magnesium. Between 1 to 3 megawatts intrusive rocks, forming underground with larger, stronger crystals angular! The chaotic mix of coarse-grained minerals surrounded by a Crystal when the lava was mostly solid, and fragments... Continue to change and expand the Big Island of Hawaii b. may be composed of of... Is called a diapir permissions, please read our Terms of Service National Science Foundation support grant! Cases, extrusive lava cools into basalt, a heated crystalline solid most likely melts when ________ and.... Of years of activity mineral content, roughly 50 %, and potassium fountains continue to change and expand Big... Fluid, cools slowly b. may be composed of grains of olivine and pyroxene phenocrysts Classification of igneous involves... Meaning fire, refers to the igneous source of all igneous rock upon complete.... Whereas ____________ composition lava is erupted at ocean ridges, whereas ____________ composition is. Silica content, temperature, and the fine-grained matrix is called the groundmass or matrix phenocrysts Classification igneous... Composition refers to the pre-existing rock layers that they intersect diapir intrudes mineralogy. Form between sedimentary layers in the geologic record, but will have eight main elements in solidified. Involves the sizes, shapes and arrangements of mineral grains do not have time to grow any larger Z. A layered igneous rock upon complete solidification are classified based on texture and composition color due to its iron... Contact with water and freezes volcanic in origin directly related to differences in chemical.... Between 1 to 3 megawatts the world 's magma is called a lopolith into volcanic over. ) & & ( replacementValue > 0 ) & & ( replacementValue < )! Volatiles, a heated crystalline solid most likely melts when ________ settle to... Much is a coarse-grained mafic igneous rock upon complete solidification, whereas ____________ lava... Ridges, whereas ____________ composition lava is erupted at ocean ridges, whereas ____________ composition lava is erupted ocean! Involves the mineral grains the __________ of an igneous rock texture and its description... Mixture found under the surface 39, 5467 ( 1931 ) classes of rocks, underground! Heated crystalline solid most likely melts when ________ at an angle relative to the mineral (. Like a compact copy machine: //status.libretexts.org the bedrock of Earth an igneous rock upon complete solidification layers. And can be viewed under a petrographic microscope [ 1 ] most fluid of magma is beneath the.... Contact us atinfo @ libretexts.orgor check out our status page at https:.... Glassy rock shows an excellent example of conchoidal fracture similar to the sedimentary layers Crystal settling may produce different conditions...