Figure 01: Igneous Rock. The lava is so hot that it flows like water. These contact features indicate an intrusive relationship between the Mount Keith Ultramafic Complex and the enclosing stratigraphy, which is consistent with the lack of definitive extrusive features. Gabbro, on the other hand is a coarse grained dark-colored rock. Expert Answer . Intrusive, Invasive, and Extrusive Komatiites and Komatiitic Basalts The komatiites and komatiitic basalts exposed at Dundonald Beach (Davis, 1997) and in drill core (Muir & Comba, 1979) range in thickness from 1m to >150m and display all of the textures typical of komatiites: glassy and rubbly flow-top 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. Home » Blog » what is the texture of an extrusive igneous rock . extrusive intrusive Peridotite Komatiite Peridotite Basalt Gabbro Mafic Andesite Diorite Intermediate Ultra-Mafic Rhyolite Granite Felsic Sodium (Na) and potassium (K) content decreases Silica (SiO 2) content decreases 70% 40% Iron (Fe), magnesium (Mg) and calcium (Ca) content increases Viscosity (thickness) of melted rock decreases Temp. The igneous rock exhibits mineral crystals too small to see with the naked eye. Komatiite is a very rare extrusive igneous rock only formed from incredibly hot magnesium-rich magma. These are also known as volcanic rocks. Phaneritic (phaner = visible) textures are typical of intrusive igneous rocks, these rocks crystallized slowly below the Earth's surface. 1. For example, you can expect to find abundant olivine, and maybe a little pyroxene and Ca-rich plagioclase in an ultramafic rock called peridotite or komatiite. We should perhaps add a note on the presence of komatiite (extrusive ultramafic rock) in our diagram, as some textbooks omit it entirely from such diagrams. Further, intrusive rocks also have a textured that is coarse grained. Hence most of the intrusive rocks grow to a much larger size when compared to extrusive rocks. ashley_rivas4. Extrusive igneous rock is produced when magma cools after it exits above the surface of the earth. This problem has been solved! Follow us for the latest industry news, company updates, and our newest features. Peridotite is the name given to intrusive ultramafic rocks, whereas komatiite is the name given to extrusive ultramafic rocks. what is the texture of an extrusive igneous rock. See the answer. Earth Science Chapter 8 42 Terms. Highlights Interleaved intrusive dacites and komatiites host the Black Swan nickel deposit. An extrusive igneous rocks definition states these rocks form when magma exits and cools above or very near the Earths surface Examples of extrusive igneous rocks include basalt andesite rhyolite dacite obsidian pumice and scoria Komatiite is a . Extrusive Igneous Rocks. 8 Practice Questions 25 Terms. Start studying Geology Igneous Rocks Extrusive and Intrusive. Its principal minerals are feldspars, quartz, and mica. Get a Quote Send Message. The magma, which is delivered to the surface via fissures or volcanic eruptions, solidifies at a faster rate. Properties of Igneous Rocks. Ch. They are formed by way of the cooling of molten magma on earth's surface. Napp, Flakstadøya, the Lofoten Archipelago, Norway. Intrusive contacts indicate komatiite intruded pre-existing dacite. andesite porphyry. For komatiite to reach the surface and erupt, it must fill a continuous liquid column within rocks whose average density is greater than that of the komatiite itself. Peridotite and komatiite are compositionally identical. Parris_Isler. Learners of English are generally not recommended to use the intrusive [r], while the linking [r] is recognized as a typical feature of the English Standard pronunciation. Peridotite and komatiite are compositionally identical. Peridotite appears to be the dominant rock type of the upper mantle. The Earth does not have conditions suitable to form komatiite and has not been in the state to form komatiite for over 2 billion years, making any komatiite formations a minimum of 2 billion years old. In addition to texture and the intrusive/extrusive determination for each sample, you will also be asked to determine the mineral content of the sample to the best of your ability. Komatiite appears in various shades of gray. extrusive - of rock material; forced out while molten through cracks in the earth's surface. Learn vocabulary, terms, and more with flashcards, games, and other study tools.