Final answer:
The rock cycle describes how sedimentary, metamorphic, and igneous rocks are transformed through geologic processes. Metamorphism is the transformation of rocks due to heat and pressure, without melting, resulting in a new metamorphic rock type depending on the conditions and original rock.
Step-by-step explanation:
The Rock Cycle and Metamorphic Rocks
The rock cycle is a geologic concept that explains how sedimentary rocks, metamorphic rocks, and igneous rocks are interconnected through various geologic processes. Through increases in temperature and pressure, without reaching the point of melting, sedimentary rocks can be transformed into metamorphic rocks. This process is known as metamorphism, and it happens deep within the Earth or at tectonic plate boundaries where significant heat and pressure can alter the minerals and structure of the pre-existing rocks. For example, limestone can be turned into marble, and shale can be transformed into slate. The type of metamorphic rock formed is influenced by the original rock, as well as the conditions of temperature and pressure it experiences.
Furthermore, metamorphic rocks themselves can undergo additional changes under different conditions, cycling back into igneous rocks when melted or becoming sedimentary rocks through weathering and erosion. This ongoing recycling process is facilitated by plate tectonics, which moves and deforms rocks within the Earth's crust, presenting the dynamic nature of our planet's geology.