Question

The nature of sedimentary rock that can undergo some irregular jointing is ___________

(a) Plastic in nature

(b) Non-plastic in nature

(c) Rich in moisture

(d) Plastic in nature and rich in moisture

I got this question in an interview for internship.

I want to ask this question from Origin of Joints and Engineering Considerations topic in section Joints and Jointing of Engineering Geology

Answer 1

The correct option is (d) Plastic in nature and rich in moisture

To elaborate: Sedimentary rocks especially those of plastic nature and rich in moisture in the initial stage (clays, shales, limestones, dolomites etc.) undergo some contraction on drying up which might have resulted into irregular jointing.