Rock formed through the cooling and solidification of magma or lava
Geologic provinces of the world (USGS)
Shield
Platform
Orogen
Basin
Large igneous province
Extended crust
Oceanic crust:
0–20 Ma
20–65 Ma
>65 Ma
Igneous rock (igneous from Latin igneus 'fiery'), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.
The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses.
Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust.
Volcanic eruptions of lava are major sources of igneous rocks. (Mayon volcano in the Philippines, erupting in 2009)Natural columns of igneous rock separated from each other by columnar joints, in Madeira
Igneousrock (igneous from Latin igneus 'fiery'), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic...
ways igneousrock can form. The other is extrusion, such as a volcanic eruption or similar event. An intrusion is any body of intrusive igneousrock, formed...
metamorphic rock, and sedimentary rock. Adakite – Volcanic rock type Andesite – Type of volcanic rock Alkali feldspar granite – Type of igneousrock rich in...
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneousrock that forms by crystallization of magma slowly...
metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneousrock such as basalt may...
is a highly vesicular rock produced in explosive volcanic eruptions.[citation needed] Most modern petrologists classify igneous rocks, including volcanic...
mineral or rock is a silicate mineral or igneousrock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic...
ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally...
erupted as pyroclastic rock than as lava flows. Rhyolitic ash-flow tuffs are among the most voluminous of continental igneousrock formations. Rhyolitic...
Granite (/ˈɡrænɪt/ GRAN-it) is a coarse-grained (phaneritic) intrusive igneousrock composed mostly of quartz, alkali feldspar, and plagioclase. It forms...
US: /bəˈsɔːlt, ˈbeɪsɔːlt/) is an aphanitic (fine-grained) extrusive igneousrock formed from the rapid cooling of low-viscosity lava rich in magnesium...
Igneous textures include the rock textures occurring in igneous rocks. Igneous textures are used by geologists in determining the mode of origin of igneous...
A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneousrock that is emplaced at depths less than 2 km (1.2 mi) within the crust...
Gabbro (/ˈɡæb.roʊ/) is a phaneritic (coarse-grained), mafic intrusive igneousrock formed from the slow cooling of magnesium-rich and iron-rich magma into...
GRAN-oh-DY-ə-ryte, GRAN-ə-) is a coarse-grained (phaneritic) intrusive igneousrock similar to granite, but containing more plagioclase feldspar than orthoclase...
Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneousrock. Types of trap rock include...
(/ˈdaɪ.əraɪt/ DY-ə-ryte) is an intrusive igneousrock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica...
coarse-grained igneousrock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than...
Syenite is a coarse-grained intrusive igneousrock with a general composition similar to that of granite, but deficient in quartz, which, if present at...
Kimberlite, an igneousrock and a rare variant of peridotite, is most commonly known to be the main host matrix for diamonds. It is named after the town...
Larvikite is an igneousrock, specifically a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar. These feldspars are...
A pegmatite is an igneousrock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes...
Andesite is an aphanitic (fine-grained) to porphyritic (coarse-grained) igneousrock that is intermediate in its content of silica and low in alkali metals...
Anorthosite (/əˈnɔːrθəsaɪt/) is a phaneritic, intrusive igneousrock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal...
the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary...
Acidic rock or acid rock refers to the chemical composition of igneous rocks that has 63% wt% SiO2 content. Rocks described as acidic usually contain...
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