Metamorphic rock is formed through the alteration of existing rock types, mainly igneous or sedimentary rocks, under extreme heat and pressure. In the rock cycle, metamorphic rocks can be found at the stage where existing rocks, due to tectonic activity, are subjected to these conditions deep within the Earth’s crust.
Through the processes of metamorphism, these rocks change in mineralogy and texture, creating new metamorphic rocks such as schist or gneiss. Once formed, metamorphic rocks can be brought to the surface through tectonic uplift or erosion. Over time, they can also be broken down into sediments and recycled into sedimentary rocks, continuing the cycle.
In summary, metamorphic rock occupies a unique position in the rock cycle, bridging the process of transformation and recycling of different rock types.