Question

what are metonorphic rocks

Answer 1

A metamorphic rock is a type of rock which has been changed by extreme heat and pressure. Its name is from 'morph' (meaning form), and 'meta' (meaning change). Metamorphic rocks are created by the physical or chemical alteration by heat and pressure of an existing igneous or sedimentary material into a denser form.Some examples of metamorphic rocks are gneiss, slate, marble, schist, and quartzite.

Answer 2

Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (100 megapascals (1,000 bar) or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock.