FAULTS, DEXTRAL AND SINISTRAL
The maximum displacement vector is close to horizontal. The sigma2 or intermediate maximum principal comressive stress is vertical. Since both thrusts and strike slip faults are formed by maximum principal stress which is horizontal, these faults interact with thrust faults and may merge into such faults in orogenic belts. The fault traces may vary from straight to slightly curved. While gavity faults cause crustal extension and the thrusts the crustal shortening, the result in case of these faults is that no net addition or subtraction of volume to the crust occurs and finite extensions and finite shortening are contained in the crust and tangential to the earth's surface. These faults can lead to very large horizontal displacements of the crust and lithosphere and may exist on all scales and occur in both oceanic and continental areas. In the latter case, they are generally called transform faults. To allow for strain compatibility the faults may be associated with stubby folds, en echelon arrangement of faults as well as folds and splays of different sense may develop pull apart basins or contractional pop outs. If the fault block away from the observer goes to the right, the fault sense is dextral, else sinistral. Common minor structures are horizontal slickensided striae and fault breccia.