Rhyolite is rarely found as lava. Extrusive Igneous Rocks Why not complete the set of stone variants with rhyolite, which is extrusive felsic, gabbro, which is intrusive mafic, and basalt, which is extrusive mafic? Granite would be a felsic rock type, and basalt would be a mafic rock type. mafic 96: - Based on your estimate, describe this rock as felsic, intermediate, mafic, or ultramafic. This diorite is closer to the classic balance of mafic and felsic minerals (salt-and-pepper appearance). Is diorite extrusive or intrusive? Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar, biotite, hornblende, and/or pyroxene. 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 It has 54 questions. In geology, felsic is an adjective describing igneous rocks that are relatively rich in elements that form feldspar and quartz. mafic. Mafic Rocks and Rhyolite We have granite, which is intrusive felsic, diorite, which is intrusive intermediate, and andesite, which is extrusive intermediate. Diorite is usually grey to dark-grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast. I hope it opens up the right the first time. ANDESITE - aphanitic rock (small crystals) of both mafic and felsic minerals. Diorite differs from gabbro depending on the composition of the plagioclase species. Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar, biotite, hornblende, and/or pyroxene. Question 1 1 pts Is diorite mafic, felsic, intermediate, or ultramafic in composition? Rhyme to remember diorite. This diorite is more salt than pepper, but it appears to have less than 10% quartz and no K-feldspar. Felsic is a generic term meaning enriched in feldspar and silica (and thus generally lower in iron and magnesium). Felsic, intermediate and mafic igneous rocks differ in their mineral composition. Mafic rocks often also contain calcium-rich varieties of plagioclase feldspar. Question Description This is Geology Unit 8 Igneous Rock 1. sample I1 has what mafic color index (MCI)? Conversely, igneous rocks rich in iron and magnesium-bearing minerals (such as amphibole and pyroxene) are darker and are classified as MAFIC, or basic. Diorite is a plutonic igneous rock with intermediate composition between mafic and felsic rocks. This ne-grained, dark-colored, igneous rock is most likely A. rhyolite B. diorite C. basalt D. gabbro page 2 Felsic … enough salt and pepper and you will diorite. Mafic rocks are darker and are composed of magnesium and iron. Use the scale above to estimate the percentage of mafic minerals in this rock. Is obsidian felsic or mafic? 15% 45% 85% 5% 30% 60% 95% Figure A5.5.1 The mafic minerals in photo A are shown as black areas in map B. Posted on August 31, 2014 by triplejunction. The term combines the words "feldspar" and "silica." The high silica content and lower temperatures of rhyolite magma result in high viscosities and violent eruptive styles. Hopefully have provided all the materials you will need for the assignment. Felsic rocks are light in color and are composed of feldspars and silicates. The mixture of mafic and felsic minerals gives the rock a "salt and pepper" appearance. Is rhyolite felsic or mafic or intermediate? intrusive. Intermediate magmas are somewhat more viscous than the mafic magmas. 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, aluminium, sodium, and potassium. Ulrich Kretschmar (Late), Derek McBride, in The Metallogeny of Lode Gold Deposits, 2016. Felsic igneous rocks are light colored. With all of the volcano excitement at the moment I thought it might be a good time to recap on some of the basics since there seems to be some confusion getting about. felsic composition? Obsidian. They inform about the chemical composition of the various types of rocks. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. Additionally, they contain somewhat more gas than do the mafic magmas, but not quite as much as the felsic magmas (see below). It thus qualifies as a diorite. Rhyolite is an extrusive felsic (silicic) volcanic rock. Diorite (red) on the QAPF diagram. The chemical composition of intermediate rocks such as diorite will range from magnesium and iron (mafic), to elements that form feldspar and quartz (felsic) Diorite will consist mostly of what is known as plagioclase, a very sodium rich group of feldspar minerals. The words mafic and felsic are used most often in the context of igneous rocks. Start studying Igneous Rocks (Mafic or Felsic). 8.8 sTudenT resPonses Sample I1 has what mafic color index (MCI)? First of all, the terms mafic and felsic generally only apply to igneous rock. I also will have the textbook attached. Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite is Felsic minerals are usually light in color and have specific gravities less than 3. Andesite is a type name that applies to igneous rocks having an intermediary composition (sort of a mix of the two, or the transition from mafic to felsic). Both felsic and mafic igneous rocks can contain feldspar minerals. Mafic rocks include basalt, its intrusive equivalent of gabbro, and a variety of less common rock types with higher or lower contents of Na and K. Andesite and its intrusive equivalent, diorite, with slightly higher silica content, are intermediate between mafic and felsic. A. pumice B. basalt C. granite D. scoria 9. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar, biotite, hornblende, and/or pyroxene. rhyolite felsic or mafic. Being of intermediate composition between felsic and mafic, diorite is classically a salt and pepper rock made largely of white to light gray plagioclase and black hornblende. Igneous Rocks. intermediate mafic felsic granite, rhyolite) (diorite, andesite) (basalt, gabbro (peridotite, etc.) It is visibly crystalline and usually has a granular texture (composed of roughly equally sized crystals) although the appearance may vary widely. Its volcanic (fine-grained) analogue is andesite. Is diorite felsic or mafic? No. Mafic and Felsic, some igneous basics. DIORITE - phaneritic rock (large crystals) of both mafic and felsic minerals. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. The chemical composition of diorite is intermediate and between felsic granite and mafic gabbro. 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). 1. determine texture: coarse-grained (visible crystals) = plutonic, fine-grained (microscopic crystals), or porphyritic (visible crystals in fine groundmass) = volcanic. Give a description of diorite "salt and pepper" visible crystals, heavy, dull and course grained. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. Those rich in quartz are classified as FELSIC, or acidic. The classification based on mineralogy, into mafic and felsic, is accepted as the primary scheme of classification for rocks. even among igneous rocks, mafic and felsic are just ranges on a "spectrum" of composition. Mafic Rock. This type of stone is usually brown to dark gray in color but Diorite can also be black and bluish-gray and Diorite is often greenish in color. 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. Common mafic rocks include basalt, diabase and gabbro. Unfortunately, I have no super close-up for you. A link between felsic rocks, the TTG suite, and lode gold Au deposits has been drawn by Burrows et al. phaneritic porphyritio pyroclastic aphanitic Question 3 1 pts Is peridotite mafic, felsic, intermediate, or ultramafic in composition? Intermediate rocks are composed of the minerals amphibole and feldspar and contain a combination of light and dark minerals. Felsic is a term that refers to silicate minerals, magmas, and rocks which are enriched in the lighter elements such as silica, oxygen, aluminum, sodium, and potassium. 5.4.3 Mafic Enclaves and the Trondhjemite-Tonalite-Granodiorite (TTG) Suite. Diorite is the name given to intrusive intermediate rocks, whereas andesite is the name given to extrusive intermediate rocks. 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