Which pair are metamorphic rocks?

Which pair are metamorphic rocks?

• A. Granite and Basalt
• B. Sandstone and Limestone
• C. Marble and Slate
• D. Coal and Shale

Answer: (C)

Metamorphic rocks form when existing rocks are altered by heat, pressure, or chemically active fluids without melting. Marble and slate exemplify this transformation: marble forms when limestone is recrystallized under heat and pressure, producing a hard, crystalline texture. Slate comes from shale that has undergone low-grade metamorphism, developing a fine foliation and the ability to split into thin sheets. The other pairs are not metamorphic: granite and basalt are igneous rocks that crystallize from molten material; sandstone and limestone are sedimentary rocks created by cementation and lithification of grains; coal and shale are also sedimentary, with coal from plant material and shale from clayey sediments.

Metamorphic rocks form when existing rocks are altered by heat, pressure, or chemically active fluids without melting. Marble and slate exemplify this transformation: marble forms when limestone is recrystallized under heat and pressure, producing a hard, crystalline texture. Slate comes from shale that has undergone low-grade metamorphism, developing a fine foliation and the ability to split into thin sheets. The other pairs are not metamorphic: granite and basalt are igneous rocks that crystallize from molten material; sandstone and limestone are sedimentary rocks created by cementation and lithification of grains; coal and shale are also sedimentary, with coal from plant material and shale from clayey sediments.