Metamorphism is the process by which existing rocks, known as parent or protolith rocks, undergo chemical, mineralogical, and structural changes due to changes in environmental conditions such as temperature, pressure, and the presence of chemically active fluids. This transformation typically occurs deep within the Earth's crust where conditions differ significantly from those at the surface. The resulting rocks, known as metamorphic rocks, can exhibit new mineral formations, foliation (layering), and differing textures compared to their original forms. Metamorphism can be classified into two main types:
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Regional Metamorphism: Associated with large-scale geological processes, such as continental collision, where rocks are subjected to high pressures and temperatures over broad areas.
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Contact Metamorphism: Occurs when rocks are heated by nearby molten magma or lava, leading to localized changes in the surrounding rocks.
Overall, metamorphism plays a significant role in the rock cycle and contributes to the diversity of geological formations within the Earth.