It is also known to be a mnemonic, combining (fe) for feldspar, (l) for lenad or feldspathoid, and (s) for silica. Necessary cookies are absolutely essential for the website to function properly. The bubbles frozen in the rocks are called vesicles. Mafic customers use basalt products to save weight, improve performance, and remain cost competitive. Mafic magmas are usually produced at spreading centers, and represent material which is newly differentiated from the upper mantle. Due to the low viscosity of the lava, the lava erupted are usually very runny. Their characteristics are medium to coarse-grained. Occurrence of igneous rocks can be either intrusive (plutonic) or extrusive (volcanic). It is of, relating to, or denoting a group of light-colored minerals, including feldspar, feldspathoids, quartz, and muscovite. On the other hand, Felsic has much higher levels of silica. Mafic rocks are darker in color than felsic rocks. Approximately, 70-85%. These rocks are also rich in other minerals like oxygen, potassium and sodium. Common mafic rocks include basalt, diabase and gabbro. Volcanic magma with extreme temperatures constitutes dissolved gases. To set some ground rules: All of these are igneous rocks. The location has high levels of silica along with water and burnt earth (due to the magma), thus making the lava sticky. Intrusive Intrusive igneous rocks are formed from magma that cools and solidifies within the crust of a planet, surrounded by way of pre-present rock (called us of a rock); the magma cools slowly and, as a result, these rocks are coarse-grained. Mafic rocks usually found in abundance include dolerite, gabbro, and basalt. The color of obsidian depends on the chemical composition of … Learn more about the Mafic vs. Felsic geological classification through this ScienceStruck article. But felsic rocks are light-coloured and have a smooth surface. 4.Mafic lava creates basalt while felsic lava produces andesitic and rhyolite rocks. The lavas that are cooled to form these rocks are also different, in terms of their viscosity. As water, along with other volatile matter, easily and gradually escapes from mafic lava, volcanic eruptions composed of mafic lava explode less violently compared to some lava of different compositions. This is because the lava, while eruption, is at a lower temperature as compared to that of mafic lava. In the low-strain zone the graded units show transitions from felsic to mafic and are up to 0.5 m thick (Fig. Whereas, felsic rocks are rich in silica and aluminium along with oxygen, sodium and potassium that gives the light shade for these rocks. Obsidian is commonly a translucent dark brown or black. Mafic lava leads to weaker volcanic eruptions. The silica level of mafic rocks is 45-55%, which is because they are originated in volcanoes present at the sea bed. This rock would have a relatively high silica content. Felsic is the term used for the rocks rich in the mental feldspar, that contains aluminium and silica at high levels. Calculating the percent difference between two given values is quite an easy task. Index Igneous rock concepts Reference Lutgens & Tarbuck Ch 3 Bjornerud Ch 2 When these gases are released, bubbles are formed. Mafic is rich in heavy minerals like magnesium and ferric, or iron. Mafic magmas are usually produced at spreading centers, and represent material which is newly differentiated from the upper mantle. An observational evaluation of the composition of an igneous rock … Crystalline Vs. Amorphous Solids - What's the Difference? d. mafic magma mixes with felsic material. Felsic is a term that is used to refer to igneous rocks rich in mineral feldspar. They are also contrastingly different in colour: Mafic being dark shades of green while Felsic is usually lightly shaded rocks. The mafic lava is usually at 950 and often leads to a weak volcanic eruption. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. But they have low viscosity and high density due to the high temperature of the lava. Felsic rocks are usually light in color and have specific gravities less than 3. A few years ago we as a company were searching for various terms and wanted to know the differences between them. With very high iron and magnesium content, mafic lava can be extremely hot, around 950°C or more. Although, the two are igneous rocks, which are defined by their levels of silica, the difference in the silica content in the two rocks, is its origin. Because of these high temperatures, the viscosity is usually low as compared with felsic lava. This is the main reason for the low density of felsic rocks. Scoria has more holes … A mafic rock like basalt generally has tales to tell of life in the mantle, while for a felsic rock like granite, whose progenitors were themselves crustal, the mantle is a nearly forgotten ancestral homeland." “The purpose of Ask Any Difference is to help people know the difference between the two terms of interest. tennisqueena. Mafic rocks are generally found in dark shades of green or greenish-black in colour. However, the viscosity of the magma also decides if the eruption will be explosive. Hint 1. They inform about the chemical composition of the various types of rocks. Our site includes quite a bit of content, so if you're having an issue finding what you're looking for, go on ahead and use that search feature there! The mafic lava usually has a low viscosity and is running. The most common examples of rocks classified as Mafic are gabbro, dolerite, and basalt. quartz alkali feldspar plagioclase feldspar olivine Crystalline and amorphous are two basic sub-types of solids, which may look similar on the outside, but are actually vastly different from the inside. felsic: glass (may contain a few minerals typical of felsic rocks) pumice: mafic: glass (may contain a few mineral typical of mafic rocks) scoria: Note: Basalt with fewer holes, known as vesicles, is called vesicular basalt. Sign up to receive the latest and greatest articles from our site automatically each week (give or take)...right to your inbox. The lavas that are cooled to form these rocks are also different, in terms of their viscosity. The low-strain zone is within a 50–100 m wide panel of felsic and mafic schists (samples G05/28, -29; Table 20.1) that can be followed north–south for >1 km. Due to their origin, the minerals found in the two rocks are also different. Mafic and felsic are the terms used to describe the silica content of igneous rocks formed on the cooling of lava. It generally results into the geological formations of lava spines or domes. Igneous rocks 20 Terms. Mafic rocks are dark in color. The mafic lava usually has a low viscosity and is running. Elord19. 6.Mafic rocks are darker in color than felsic rocks. Thus, these rocks have low density unlike mafic rock, which have high density are heavy. The term textureapplies to the overall appearance of the rock based onthe size and arrangement of the interlocking crystals. Volcanic rocks are the primary formations studied in order to reveal new geological facts. Well, we're looking for good writers who want to spread the word. Igneous Rocks. Felsic rocks, in general, form the bulk of the continental plates, while mafic basalt forms the seafloor. The most common felsic rock is granite, which represents the purified end product of the earth’s internal differentiation process. Ask Any Difference >> Science >> Difference Between Mafic and Felsic (With Table). Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. So, what is it?eval(ez_write_tag([[468,60],'askanydifference_com-box-3','ezslot_6',148,'0','0'])); 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. Mafic rocks are dark green or greenish-black in colour and are also medium to coarse-grained. Mafic has low levels of silica. YOU MIGHT ALSO LIKE... Igneous Rock Texture & Process 8 Terms. The word Mafic comes from (ma) for magnesium and (f) for ferrum or the Latin for iron. (Please note that some geologists with questionable motives switch the order of the magnesium and iron and come up with the term "femag." 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