Question

At a dam site, a bed of sandstone is exposed on horizontal ground. If it is 25° towards East. Its width of outcrop on a level ground is 240 m, what is its vertical thickness?

(a) 101.9 m

(b) 99.9 m

(c) 111.9 m

(d) 121.9 m

This question was addressed to me during an internship interview.

The doubt is from Rocks Basic Terms topic in portion Structural Features of Rocks of Engineering Geology

Answer 1

Correct choice is (c) 111.9 m

To elaborate: Vertical thickness = Width of outcrop * tan (angle of inclination)

Vertical thickness = 240 * tan (25°) = 111.91 m