# Folds

Bending of rocks due to plastic deformation is expressed in nature by folds. Every fold contains an imaginary **axial plane** which divides the fold as symmetric as possible in two different halves, dividing the fold into two limbs. The **fold axi**s is the line formed where the axial plane intersects folded rock layer as shown in the line a-b.

Folds having both limbs dipping towards the fold axis are called **synclines,** while folds of which limbs are dipping away from the fold axis are called **anticlines.**