Question

Which type of strata is rare in occurrence?

(a) Vertical strata

(b) Horizontal strata

(c) Inclined strata

(d) Jointed strata

The question was asked at a job interview.

I need to ask this question from Geological Investigations in section Tunnels of Engineering Geology

Answer 1

Right answer is (b) Horizontal strata

For explanation I would say: Horizontal strata are rare in occurrence for longer tunnels. If they are countered for small tunnels or short lengths of long tunnels, horizontally layered rocks might be considered quite favourable.