A metamorphic rock with minerals aligned in a preferred orientation or with layered variations is described as having what fabric?

• A. Foliation
• B. Schistosity
• C. Porphyroblastic texture
• D. Polygonal texture

Answer: (A)

Foliation describes a planar fabric in metamorphic rocks formed when minerals realign under directed pressure, producing a preferred orientation or layered variation. This alignment happens as minerals like micas or chlorite elongate and partition into parallel sheets, telling you the rock experienced differential stress during metamorphism. The description—minerals aligned in a preferred direction or showing layered variations—fits foliation because it captures the key idea of a fabric defined by planarity and alignment.

Other textures describe different features but not this fabric. Porphyroblastic texture involves large crystals (porphyroblasts) set in a finer groundmass, not an oriented sheet-like fabric. Polygonal texture refers to grains with polygonal outlines from recrystallization without a preferred orientation. Schistosity is a specific type of foliation seen in schists, where large platy minerals give a conspicuous, schistose appearance; the general term for the described fabric remains foliation.