Metamorphic rocks are formed through which of the following processes?

Metamorphic rocks form through the process of heat and pressure acting on existing rocks, which can be either igneous, sedimentary, or even other metamorphic rocks. This transformative process causes changes in the mineral composition and texture of the rock, creating new metamorphic minerals and a distinct texture known as foliation or banding. The conditions under which this transformation occurs are typically deep within the Earth's crust, where high temperatures and pressures are present.

The other processes associated with the formation of rocks involve different mechanisms. The cooling of magma or lava leads to the formation of igneous rocks, while the compaction of sediments results in sedimentary rocks. Direct crystallization from minerals typically refers to the formation of igneous rocks as well, where minerals crystallize upon cooling from a molten state. Understanding these processes helps clarify the distinct characteristics that differentiate metamorphic rocks from other rock types.