Foliation in geology refers to repetitive layering in metamorphic rocks. Each layer can be as thin as a sheet of paper, or over a meter in thickness. The word comes from the Latin folium, meaning "leaf", and refers to the sheet-like planar structure. It is caused by shearing forces, or differential pressure.

What does foliated mean in science?

Foliated Metamorphic Rocks:

(Foliated means the parallel arrangement of certain mineral grains that gives the rock a striped appearance.) Foliation forms when pressure squeezes the flat or elongate minerals within a rock so they become aligned.

What does the word foliated mean?

1 : composed of or separable into layers a foliated rock. 2 : ornamented with foils or a leaf design.