Dunite is an igneous, plutonic rock, of ultramafic composition, with coarse grained or phaneritic texture. The mineral assemblage is typically greater than 90% olivine with minor pyroxene and chromite. Dunite is the olivine rich endmember of the peridotite group of mantle derived rocks. Dunite and other peridotite rocks are considered to represent the Earth's mantle. Dunite is rarely found within continental rocks, but where it is found, it typically occurs at the base of ophiolite sequences where slabs of mantle rock from a subduction zone have been thrust into continental crust by obduction during continental or island arc collisions (orogeny). Dunite typically undergoes retrograde metamorphism in near surface environments and is altered to serpentinite. Volcanic rock on North America Plutonic rock on North America Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Bold text --202. ... Ultramafic rocks are igneous rocks with very low silica content (less than 45%) and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... Olivine The mineral olivine is a magnesium iron silicate with the formula (Mg,Fe)2SiO4 in which the ratio of magnesium and iron varies between the two endmembers of the series: forsterite (Mg-rich) and fayalite (Fe-rich). ... The pyroxenes are a group of important rock-forming silicate minerals found in many igneous and metamorphic rocks. ... Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. ... Peridotite Peridotite is a dense, coarse grained ultrabasic rock, consisting mainly of the minerals olivine and pyroxene. ... Earth cutaway from core to exosphere. ... Ophiolites are sections of the oceanic crust and the subjacent upper mantle that have been uplifted or emplaced to be exposed within continental crustal rocks. ... Categories: Geology stubs | Plate tectonics ... The Continental Crust is the layer of granitic and sedimentary rock which forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. ... Obduction is the overthrusting of continental crust by oceanic crust or mantle rocks. ... An island arc is a type of archipelago formed by plate tectonics as one oceanic tectonic plate subducts under another and produces magma. ... In geology, orogeny is the process of mountain building. ... Serpentinite is a rock comprised of an admixture of serpentine minerals. ...

Dunite was named by the Austrian geologist, Ferdinand von Hochstetter in 1859 after Dun Mountain near Nelson, New Zealand. Dun Mountain was given its name because of the dun colour of its vegetation which is itself a reflection of underlying ultramafic rocks. Ferdinand Christan, baron von Hochstetter (April 30, 1829 - July 18, 1884), was an Austrian geologist. ... 1859 is a common year starting on Saturday. ... Nelson is the name of several towns, cities, counties, regions around the world: Nelson, New Zealand Nelson, Lancashire, England Nelson, British Columbia Nelson, Georgia Nelson, Illinois Nelson, Missouri Nelson, Minnesota Nelson, Nebraska Nelson, New Hampshire Nelson, New York Nelson, Wisconsin Nelson County, Kentucky Nelson County, North Dakota Nelson County, Virginia...

Dunite should not be confused with the explosive dunnite. Dunnite Also known as Explosive D. Ammonium picrate Developed by Major Dunn in 1906 and used extensively by the US Navy during World War I. Dunnite is a relatively insensitive explosive which meant it was useful for amour piercing shells, exploding only after the shell had actually pierced the armour. ...