Structural Geology

Structural geology is the systematic study of the deformed rocks which constitute the planet Earth’s upper layers of geological materials. Thus, it is the study of the deformation of the Earth from a planetary perspective as the major structural features are described. It also describes the situation and processes by which the upper layers of the planet undergo horizontal and vertical displacement.

In the universe, each planet or moon exhibits its own distinctive process and style of deformation. This reflects the degree of movement of the planetary interior as well as its ratio of volume. As a planet radius increases, the rate of cooling of the planet drops, since there is less surface area to cool across. Thus, larger planets are hotter and more mobile, due to the dependence of rock strength on temperature. This causes a planet interior to be able to flow plastically.

While the bed of rock lying on the surface of a planet is brittle and relatively weak, the rocks that lie deeper underneath are stronger, due to pressure. However, when we reach some depth, the effect of increasing temperature causes the rock strength to drop as it become weaker the deeper we go. Hence, the a layer of high rock strength is found near the surface of a planet. This geological layer is called lithosphere, with ‘litho’ meaning rock. The most fundamental structural property of the Earth is the distinction between ocean basins and continents, which are the most obvious features of its surface. The boundary that divides continent from ocean is found at 2000 m below sea level.

The continents of the planet consists largely of 100/3000 million years old rocks, which have been repeatedly deformed. They are rich in quartz and feldspar.