Question

In which cause of folding, the thickness of fold does not remain uniform?

(a) Flexural folding

(b) Shear folding

(c) Flowage folding

(d) Flexural tension

This question was addressed to me during an interview.

This interesting question is from Causes of Folding topic in section Folds and Folding of Engineering Geology

Answer 1

Right option is (c) Flowage folding

For explanation I would say: During the compression due to flowage folding, the material of the involved layers behaves almost as a viscous or plastic mass and gets buckled up and deformed at varying rates suffering unequal distortion. In such cases the thickness of the resulting fold does not remain uniform.