Final answer:
When a metamorphic rock is melted, it becomes magma or molten rock, representing part of the rock cycle. Metamorphism transforms existing rocks under heat and pressure without melting. If melting occurs, the material enters the igneous part of the rock cycle as magma.
"The correct option is approximately option d"
Step-by-step explanation:
If you have a metamorphic rock and melt it, what does it become? The correct answer is d. Magma or molten rock. Metamorphic rocks, just like any other type of rock, when subjected to temperatures high enough to cause them to melt, will turn into magma or molten rock. This molten material is essentially a mixture of various minerals found in the rock that have been liquified due to extreme heat.
Metamorphism is the process through which a pre-existing rock type, known as the protolith, is transformed into a metamorphic rock. This transformation occurs under conditions of high temperature and pressure, but the rock does not melt in this process. Should the rock melt, it would no longer be considered metamorphism but rather part of the magmatic or igneous process.
When rocks on Earth's surface or crust are pushed deeper into the mantle by tectonic forces, they are subjected to increased temperatures and pressures, and if these conditions are high enough to surpass the rock's melting point, it becomes magma. This magma can then cool and solidify to eventually form what we classify as igneous rocks.
The ability of rocks to undergo this type of change is part of what is known as the rock cycle, an essential Earth process through which rock materials are recycled over geologic time. Metamorphic rocks can become magma, which upon cooling becomes an igneous rock.
These igneous rocks can then be weathered and eroded into sediments, which under compaction and cementation turn into sedimentary rocks. Furthermore, any of these rock types can undergo further changes to become metamorphic rocks, thus completing the cycle.