Mining Geology MCQs Questions & Answers | Mining Engineering

Denudation is the geological process that refers to the wearing away and removal of exposed country rocks from the Earth’s surface by natural agents such as running water, glaciers, wind, and waves.

It includes processes like weathering, erosion, transportation, and mass wasting, which together lower and reshape the land surface.

Option A: Attrition refers to the mutual wear and rounding of rock particles when they collide with one another, not the general wearing away of exposed rocks.

Option B: Mantle refers to a geological layer inside the Earth, not a surface process.

Option D: Deflation refers specifically to the removal of loose fine particles by wind, not the overall wear and tear of rocks.

Thus, the process of wear and tear of exposed country rocks is best defined as Denudation.

Mural joints are vertical joints that commonly develop in massive igneous rocks, especially in granite bodies.

They are formed due to contraction and release of stresses during the cooling and solidification of the granite mass.

These joints are called mural joints because they appear like the walls of a structure, often intersecting at right angles.

Option A: Basalt usually develops columnar joints, not mural joints.

Option C: Sandstone may show bedding and fracture joints but not mural joints.

Option D: None is incorrect because mural joints specifically occur in granite.

Therefore, mural joints are typically developed in granite.