Answer:
Metamorphic rocks (from the Greek meta, change, and morphe, form, "change of shape") result from the transformation of pre-existing rocks that have undergone structural and mineralogical adjustments under certain physical or chemical conditions, or a combination of both, such as the temperature, pressure and / or chemical activity of the fluids agents of metamorphism These adjustments, imposed exclusively under the surface, transform the original rock without losing its solid state, generating a metamorphic rock. The rock generated depends on the composition and texture of the original rock, the agents of metamorphism, as well as the time in which the original rock was subjected to the effects of the so-called metamorphic process. Due to the nature of their origin, there may be a complete gradation between metamorphic rocks and the igneous or sedimentary rocks from which they were formed. The study of these rocks provides very valuable information about the geological events that occurred within the Earth and about their variation through time.
Explanation:
To classify a metamorphic rock, the type of metamorphism involved must be known, which can be variable since it depends on the criteria that are taken as a basis to differentiate it: it can be classified from the point of view of extension, fit and cause , geological value, increase or decrease in temperature, etc., but it is very common to define three main types of metamorphism according to the predominant metamorphic agent: Regional, Contact and Dynamic.
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