Question

The orientations of the fold axis and axial plane in the given figure indicate 

• A. reclined fold
• B. vertical fold
• C. recumbent fold
• D. horizontal fold

Hint:

In fold classification, a recumbent fold is characterized by a horizontal or nearly horizontal axial plane with nearly parallel limbs.

Answer 1

The Correct Option is A

In the stereonet, the fold axis is plotted as a point inside the net, not on the primitive → the fold axis is plunging (not horizontal).

The axial plane is shown as a curved great circle that is neither vertical nor horizontal, indicating the axial plane is inclined.

Fold classification depends on:

• Fold axis plunging
• Axial plane inclined

Comparison with options:

Reclined fold → plunging fold axis + inclined axial plane

Vertical fold → axial plane vertical 

Recumbent fold → axial plane nearly horizontal 

Horizontal fold → fold axis horizontal 

Answer: (A)