It is commonly erupted as passive lava flows due to its low viscosity (resulting from high magmatic temperatures and low silica contents). answer! Common rock-forming mafic minerals include olivine, pyroxene, amphibole, biotite mica, and the plagioclase feldspars. Mafic rocks are rich in the heavy minerals, iron and magnesium. Obsidian consists mainly of SiO 2 (silicon dioxide), usually 70% or more. Mafic definition, of or relating to rocks rich in dark, ferromagnesian minerals. Mafic lava, before cooling, has a lower viscosity than felsic lava due to its lower silica content. Read More on This Topic It is an extremely vesicular basaltic lava with very small ( 1mm) vesicles. Mafic rocks are abundant in the Earth's crust beneath the oceans. 5.Either in describing rocks or lava, mafic means that the lava or rock has less silica while felsic implies that the lava or rock has the most silica. Mafic magmas are usually produced at spreading centers, and represent material which is newly differentiated from the upper mantle. MAFIC Mafic lava is basically known as rock formation basalt. Gabbro and basalt are both dark Texture: granite shows a range of grain sizes. Felsic. The low density and light-weight, ascribable to the presence of light-weight minerals such as oxygen, sodium and potassium. Obsidian has a very high SiO 2 percent. Light-colored Rhyolite Porphyritic Andesite. Hence, there are much more pores in pumice than in scoria and they are smaller. Mafic rocks derive from basalt … It offers compelling performance, enabling lightweight composites of the future. as coarse-grained plutonic rocks are porphyraceous. The most common felsic rock is granite, which represents the purified end product of the earth’s internal differentiation process. The felsic minerals include quartz, tridymite, cristobalite, feldspars (plagioclase and alkali feldspar), feldspathoids (nepheline and leucite), muscovite, and corundum. Basalt... Our experts can answer your tough homework and study questions. Felsic rocks are light in color and are composed of feldspars and silicates. So, what is it? Mafic lava produces basalt while felsic lava originates rhyolite and andesitic rocks. The difference in the level of silica present in the two arises from the origin of the two rocks. Approximately, 70-85%. Felsic is also rich in low-density minerals like oxygen, sodium and potassium. Basalt Fiber is made from natural basalt rock. The mafic magmas are somewhat more viscous than the ultramafic magmas, but they are still fairly fluid. Create your account. The words mafic and felsic are related to the color of the rock. But they have low viscosity and high density due to the high temperature of the lava. A dominant component of oceanic crust, basalt is the most abundant volcanic rock. Is the mantle mafic or felsic? A common mafic rock is basalt. 4.Mafic lava creates basalt while felsic lava produces andesitic and rhyolite rocks. The word derives from a composite of the chemical symbols for Magnesium (Ma) and Iron (Fe). Mafic rocks are darker and are composed of magnesium and iron. Felsic is the term used for the rocks rich in the mental feldspar, that contains aluminium and silica at high levels. youfancyyhuh. felsic. Scoria is a dark-colored igneous rock with abundant round bubble-like cavities known as vesicles. Since igneous rocks are characterised by silica content in them, mafic is the one with less silica content (approx. These minerals are high in magnesium and ferric oxides, and their presence gives mafic rock its characteristic dark colour. 1. determine texture: coarse-grained (visible crystals) = plutonic, fine-grained (microscopic crystals), or porphyritic (visible crystals in fine groundmass) = volcanic. Common mafic rocks include basalt and gabbro. They are also contrastingly different in colour: Mafic being dark shades of green while Felsic is usually lightly shaded rocks. Igneous rocks consist of primarily 12 types of oxides. Mafic is an adjective describing a silicate mineral or igneous rock that is rich in magnesium and iron, and is thus a portmanteau of magnesium and ferric. https://www.sciencedirect.com/science/article/pii/S0024493704002014, https://mingtang.me/publications/Tang%20et%20al_Science%202016.pdf, Comparison Table Between Mafic and Felsic, Main Differences Between Mafic and Felsic, Difference Between Lucifer and Satan (With Table), Difference Between Parrot and Macaw (With Table), Low viscosity due to the high temperature of lava. Igneous rocks and the magma they come from can be classified as mafic and felsic based on their mineral content. Mafic’s new Shelby NC location is set to be the largest Basalt Fiber Production Facility in the World © copyright 2003-2020 Study.com. That’s why gas bubbles can move more freely and join each other and form larger vesicules. Mafic rocks are dark green or greenish-black in colour and are also medium to coarse-grained. 2. determine color/composition: mostly light minerals = felsic; half light, half black (or gray in fine grained rocks) = intermediate; mostly black minerals = mafic; mostly olivine = ultramafic As nouns the difference between mafic and basalt is that mafic is a rock with such properties while basalt is (mineral) a hard mafic igneous rock of varied mineral content; volcanic in origin, it makes up much of the earth's oceanic crust. Igneous Rocks. Ask Any Difference is a website that is owned and operated by Indragni Solutions. 45-55%) while felsic is the one with a greater silica content (approx.70-90%). GLASSY TEXTURE Rhyolite: felsic with an aphanitic texture (so fine-grained that their component mineral crystals are not detectable by the unaided eye) Basalt porphyry: mafic with a porphyritic texture (containing distinct crystals or crystalline particles embedded in a fine-grained groundmass) Vesicular Basalt. Mafic rocks contain heavier elements and include basalt … What are bright streaks around a moon crater? This is the main reason for the low density of felsic rocks. Mafic is the acronym for magnesium and ferric (Latin for Iron) because this igneous rock is rich in these two minerals. PORPHYRITIC TEXTURE - an igneou… Graphite is found to have 70% of silica. Common mafic rocks include basalt and its coarse-grained intrusive equivalent, gabbro. - Definition, Uses & Composition, Working Scholars® Bringing Tuition-Free College to the Community. Scoria has more holes and may be black or red in color. This is the mineral that gives basalt its dark color. Approximately only 45-55%. Felsic is a term that is used to refer to igneous rocks rich in mineral feldspar. Is Basalt felsic? This magma has a low viscosity, which allows for gases to escape the volcano, and for the lava flows to erupt calmly and predictably. intermediate. They tend to have high Silicon content, also known as Silica content. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks (basalt and gabbro) are very dark in color and very dense because of their high iron content. Crystalline rocks with obsidian's composition include granite and rhyolite. tennisqueena. Well, as you can see, mankind is very good when a need arises to make simple concepts difficult to understand. 1. determine texture: coarse-grained (visible crystals) = plutonic, fine-grained (microscopic crystals), or porphyritic (visible crystals in fine groundmass) = volcanic. There is one important exception to the dark = mafic rule, and that is aphanitic, vesicle-free, black or very dark-gray glass that is called obsidian. FELSIC ROCKS Thus, they were categorised into four types: ultramafic, mafic, intermediate and felsic, in their increasing order of silica content present. These are interpreted to be small blobs of immiscible mafic magma within a larger felsic … Igneous rocks are those that crystallize from magma, or liquid rock. Mafic has low levels of silica. 3. The below picture is of the mafic rock basalt. Sometimes, they are also used to differentiate the characteristics of the lava (or magma). Igneous rocks on chemical analysis were found to be abundant in silicate oxides and therefore it was decided that these igneous rocks would be differentiated based on their silica content. Silica content in Mafic rocks is around 50% by weight. The type of lava emitted in an eruption can reveal intimate details of the inner working… A mafic rock can be extrusive like basalt, or intrusive like gabbro. The high silica content (70-85%) is because of the geographical location the felsic rocks are found at. Most of these rocks are gray though Mafic rocks are also found in brown, green, and even black colors. The felsic lava is usually found at 650-750˚ C and is can cause explosive volcanic eruptions. Approximately, 70-85%. Texture: aphanitic; Composition: mafic (enriched in iron and magnesium) See more.
This category only includes cookies that ensures basic functionalities and security features of the website. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Olivine occurs … Felsics’s tendency to cap steam and other gases means eruptions of an explosive nature are more likely 4.Mafic lava creates basalt while felsic lava produces andesitic and rhyolite rocks. Basalt, one of the common examples of Mafic rock has only 50% silica content. It is also known to be a mnemonic, combining (fe) for feldspar, (l) for lenad or feldspathoid, and (s) for silica. 3.Mafic lava induces weaker eruptions as opposed to the stronger eruptions in felsic lava. Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium.  Geologists have divided the island's mafic and felsic rocks into different named sequences and sub-divided mafic rocks based on their ratio of zirconium and niobium. c. volcanoes lie on continental margins inland of subduction zones. nadineklein. Whereas, felsic rocks have high viscosity. In terms of chemistry, mafic rocks are on the other side of the rock spectrum from the so-called felsic rocks. These rocks are also rich in other minerals like oxygen, potassium and sodium. No. The lavas that are cooled to form these rocks are also different, in terms of their viscosity. Felsic. The silica level of mafic rocks is 45-55%, which is because they are originated in volcanoes present at the sea bed. Felsic rocks and magma contain high levels of feldspar and silicon. Gabbro is the name given to intrusive mafic rocks, whereas basalt is the name given to extrusive mafic rocks. Intermediate rocks are composed of the minerals amphibole and feldspar and contain a combination of light and dark minerals. All other trademarks and copyrights are the property of their respective owners. - Definition, History, Facts & Topics, What is Deformation? Porphyritic Basalt. Gabbro is a phaneritic (coarse-grained), mafic intrusive igneous rock formed from the slow cooling of magnesium-rich and iron-rich magma into a holocrystalline mass deep beneath the Earth's surface. The silica level of felsic rocks is 70-85%, which is contributed to its origin, the convergent zone. BASALT - aphanitic (small crystals) of mafic minerals: olivene, pyroxene, etc. Common mafic rocks include basalt, dolerite, and gabbro. Granite and rhyolite are considered felsic, while basalt and gabbro are mafic (click here for more information on mafic and felsic). For similar determinations, glasses can also be prepared in the laboratory from crystalline rocks. 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