Diastrophism refers to movements and deformations of the Earth's crust. Forces acting on the crust can cause it to fold, fault, or trench. Folding occurs when crust crumples and bends, faulting when it fractures, and trenching when large rock masses slide against each other. These movements are driven by processes like plate tectonics, where continental plates slowly move and interact at boundaries, which can cause earthquakes and volcanic activity. Evidence like matching fossil and rock formations between separated continents supports the theory of plate tectonics and the past existence of supercontinents like Pangaea.

1. Diastrophism Chapter 6