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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.
As it moves, it cools and various rock types will form through a process known as fractional crystallisation. Igneous rocks can be seen at mid-ocean ridges, areas of island arc volcanism or in intra-plate hotspots. Metamorphic rocks once existed as igneous or sedimentary rocks, but have been subjected to varying degrees of pressure and heat ...
Fractional crystallization, or crystal fractionation, is one of the most important geochemical and physical processes operating within crust and mantle of a rocky planetary body, such as the Earth. It is important in the formation of igneous rocks because it is one of the main processes of magmatic differentiation. [1]
This diamond is a mineral from within an igneous or metamorphic rock that formed at high temperature and pressure. The rock cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.
Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term rock formation can also refer to specific sedimentary strata or other rock unit in stratigraphic and petrologic studies. A rock structure can be created in any rock type or combination: Igneous rocks are created when molten rock cools and ...
Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form". The result is a profound change in physical properties ...
Petrogenesis, also known as petrogeny, is a branch of petrology dealing with the origin and formation of rocks. While the word petrogenesis is most commonly used to refer to the processes that form igneous rocks, it can also include metamorphic and sedimentary processes, including diagenesis and metamorphic reactions.
Plutonism is the geologic theory that the igneous rocks forming the Earth originated from intrusive magmatic activity, with a continuing gradual process of weathering and erosion wearing away rocks, which were then deposited on the sea bed, re-formed into layers of sedimentary rock by heat and pressure, and raised again.