Classifications of Faults

The classification of faults is even yet the subject of vigorous discussion and no general agreement has been reached, so that instead of defining the faults based on the classification, the various types of faults are described as under

(1) Normal fault

The Fault that results from horizontal tensional stresses in brittle rocks and where the hanging-wall block has moved down relative to the footwall block is called as normal fault. It has a high angle of dip. (Fig. 3.4)

(2) Reverse fault

The Fault that results from horizontal compression stresses in brittle rocks and where the hanging-wall block has moved up relative to the footwall block is called as normal fault. It has an angle of fault. (Fig. 3.5)

(3) Strike Fault

These faults are those which run parallel, or nearly so, to the strike of the beds.

(4) Dip Faults

The fault in which the fault plane is parallel to the dip of the beds is called as dip fault. These are less important than strike-faults, having generally a smaller throw and less length. Dip-faults cut across the strike of the beds and interrupt the continuity by producing an offset in the outcrop.

(5)Strike slip faults

The fault in which the net sip is parallel to the strike of the fault is called as strike slip fault. (Fig.3.6). It is also called as wrench fault.

(6)Dip slip faults

The fault in which the slip occurs is parallel to the dip of the beds is called as dip slip fault. (Fig.3.7)

(7) Step Faults

A series of parallel faults, in which the successive movement of each block takes the stair like appearance and all heading in the same direction, are called step faults. (Fig. 3.8)

(8) Parallel faults

A series of faults, in which the successive movement of each block takes in the same direction having the same strike and dip are called parallel faults

(9) Hinge faults

The fault in which one block rotates with respect to other block, is called as hinge fault (Fig 3.9)

(10) Emergent Faults

The fault which cuts the structure of the earth is called emergent fault (figure 3. 10.)