Element of Folds

1.Limb

• The sloping sides of the fold are called the limb

3.Crest

• The curved portion of the fold at the top are called the crest.

4.Trough

• The curved portion of the fold at the bottom is called the trough.

5.Axial plane

• An imaginary plane which divides the fold into two equal halves is called the axial plane.

6.Axis

• The line of intersection between the axial plane and the surface of any of the constituent rock bed is called the axis of fold

7.Plunge of fold

• The inclination of the fold axis with the horizontal is called the plunge of fold.

Elements of fold are shown in Fig 3.11