Question

In a single layer of an anticlinal, the dip isogons converge towards the inner surface (core). Which one of the following statements is correct for the curvature of the inner surface of this folded layer?

• A. Curvature of the inner surface > Curvature of the outer surface
• B. Curvature of the inner surface < Curvature of the outer surface
• C. Curvature of the inner surface = Curvature of the outer surface
• D. Curvature of the inner surface = Curvature of the median surface

Hint:

In anticlines, the curvature is more intense on the inner (core) surfaces due to compression, while the outer surfaces are stretched and have less curvature.

Answer 1

The Correct Option is A

Step 1: Read the isogon clue.
In this single folded layer the dip isogons close in toward the core, the inner side of the fold. This pattern tells us how the two surfaces curve.

Step 2: Picture an anticline.
In an anticline the outer arc is stretched out, while the inner arc is squeezed into a tighter bend. A tighter bend means a sharper curve.

Step 3: Compare the curvatures.
Because the inner surface bends more tightly, its curvature is larger than that of the gently stretched outer surface.

Step 4: Match to the options.
This means curvature of the inner surface is greater than curvature of the outer surface. The equal options do not fit a fold where isogons converge inward.

Step 5: Final choice.
So the inner surface has the greater curvature.
\[ \boxed{\text{Curvature of the inner surface > Curvature of the outer surface}} \]