What is a metamorphic rock?
Q: What is a metamorphic rock?
A: A metamorphic rock is a type of rock which has been changed by extreme heat and pressure. Its name comes from 'morph' (meaning form), and 'meta' (meaning change). The original rock gets heated (temperatures greater than 150 to 200°C) and pressured (1500 bars), resulting in profound physical and/or chemical changes.
Q: What are some examples of metamorphic rocks?
A: Examples of metamorphic rocks include marble, which is formed from limestone; slate, which is a metamorphic mudstone or shale; and quartzite, which is a metamorphic sandstone.
Q: How are metamorphic rocks formed?
A: Metamorphic rocks are formed when igneous or sedimentary rocks are subjected to extreme heat and pressure. As a result they undergo a complete change in their form and characteristics.
Q: What happens to fossils contained within the original rock during the formation process?
A: During the formation process, the recrystallisation of minerals after heating generally causes the destruction of any fossils that may have been contained within the original rock.
Q: Where does this intense heat and pressure come from?
A: The intense heat and pressure required for forming these types of rocks typically comes from deep within Earth's surface - such as at the root of mountain chains or volcanoes - where there will be enough force to cause shape-shifting in strata layers as well as changes in mineral composition.
Q: What temperatures must be reached for this transformation to occur?
A: For transformation into a metamorphic rock to occur, temperatures greater than 150-200°C must be reached.
