metamórficas

Metamórficas refers to metamorphic rocks, a type of rock that has been changed from its original form by heat, pressure, or chemical reactions. These transformations occur deep within the Earth's crust or when rocks are subjected to the intense conditions associated with tectonic plate collisions. The original rock, known as the protolith, can be igneous, sedimentary, or even another metamorphic rock.

The process of metamorphism does not melt the rock entirely but rather causes significant changes in its mineral composition, texture, and structure. New minerals can form, and existing minerals can recrystallize and align themselves in a particular orientation, leading to a foliated texture. Foliation is characterized by parallel layers or bands, often seen in rocks like slate, schist, and gneiss. Non-foliated metamorphic rocks, such as marble and quartzite, do not exhibit this layered appearance.

The type and degree of metamorphism depend on factors like temperature, pressure, and the presence of chemically active fluids. Regional metamorphism occurs over large areas, typically associated with mountain building, while contact metamorphism happens when rocks are exposed to the heat of nearby magma intrusions. The study of metamorphic rocks provides valuable insights into the geological history and processes of the Earth's interior.