Magmatic differentiation is the process by which different types of igneous rocks are formed from a single parent magma through various physical and chemical processes. Here are some key processes and mechanisms involved in magmatic differentiation:
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Crystal Fractionation: As magma cools, minerals crystallize out of the melt at different temperatures. This can lead to a more evolved melt composition as various minerals settle out of the liquid.
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Partial Melting: In this process, only a portion of a rock melts, resulting in a magma with a composition different from the original rock.
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Mixing of Magmas: Two or more different magmas can mix and produce a hybrid magma with a different composition.
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Assimilation: This occurs when the magma incorporates and melts surrounding (country) rocks, altering the composition of the magma.
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Volatile Exsolution: As magma rises, pressure decreases, allowing gases (volatiles) dissolved in the melt to exsolve. The loss of volatiles can change the composition of the remaining melt.
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Thermal Metamorphism: Heat from the magma can alter nearby rocks, potentially adding new components to the magma or changing its mineralogy.
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Sediment Recycling: In subduction zones, sediments can be subducted and partially melted, contributing to the formation of new magma with different compositions.
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Hydrothermal Processes: Fluids released from cooling magma can alter the surrounding rocks and even the melt itself, affecting mineral composition.
These processes collectively contribute to the diversity of igneous rocks found in the Earth's crust, leading to the formation of various types such as basalt, andesite, diorite, granite, and others.
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