Which rock type forms from the transformation of existing rocks under heat and pressure?

Which rock type forms from the transformation of existing rocks under heat and pressure?

• A. Igneous Rock
• B. Sedimentary Rock
• C. Quartzite
• D. Metamorphic Rock

Answer: (D)

Metamorphism is the process that changes existing rocks into new rocks under heat and pressure deep in the crust, causing minerals to recrystallize and realign while the rock remains solid rather than melting. This solid-state transformation produces new textures and mineral assemblages, such as slate, schist, or gneiss, which are characteristic of metamorphic rocks. The general category described by the question is metamorphic rock. Igneous rocks form from the cooling and solidification of molten material, while sedimentary rocks form from sediments that have been compacted and cemented. Quartzite is a specific metamorphic rock formed from sandstone, showing how a protolith can become metamorphic; but the rock type in general is metamorphic rock.

Metamorphism is the process that changes existing rocks into new rocks under heat and pressure deep in the crust, causing minerals to recrystallize and realign while the rock remains solid rather than melting. This solid-state transformation produces new textures and mineral assemblages, such as slate, schist, or gneiss, which are characteristic of metamorphic rocks. The general category described by the question is metamorphic rock. Igneous rocks form from the cooling and solidification of molten material, while sedimentary rocks form from sediments that have been compacted and cemented. Quartzite is a specific metamorphic rock formed from sandstone, showing how a protolith can become metamorphic; but the rock type in general is metamorphic rock.