ABSTRACT
In this chapter we will consider the fracturing of geological strata and the development of faults affecting the earth’s crust. This is an important subject because the interplay of faults gives rise to earthquakes and the disasters they cause. A distinction is very often made between the discontinuous deformation giving rise to faults and continuous deformation giving rise to folds, for example, as if these two deformation modes were incompatible. We will see below that in reality they frequently combine. Nevertheless, it is worthwhile specifying some particular features of faults. A fault is a fracture, a break along which there is relative displacement between the two blocks it separates. Faults are the characteristic feature of the discontinuous tectonics specific to the upper part of the earth’s crust. We first address the question in a theoretical way: how and why do rocks fracture? The various categories of faults are then described in geological terms before the 3D models are presented.
