Archibald Geikie and John Allen Howe

“ In coal and metal mining it is evident from what has already been said that faults must act sometimes beneficially, sometimes the reverse. It is a common occurrence for fault-fissures and fault-rock to appear as valuable mineral lodes through the infilling or impregnation of the spaces and broken ground with mineral ores.
In certain regions which have been subjected to very great crustal disturbance a type of fault is found which possesses a very low hade—sometimes only a few degrees from the horizontal—and, like a reversed fault, hades beneath the upthrown mass ”

“ The angle made by the fault-plane with the vertical is the hade of the fault (if the angle of inclination were measured from the horizon, as in determining the “dip” of strata, this would be expressed as the “dip of the fault”) . In figs. 1 and 2 the faults are hading towards the right of the reader. The amount of dislocation as measured along a fault-plane is the displacement of the fault (for an illustration of these terms see fig. 18, where they are applied to a thrust fault) ; the vertical displacement is the throw (Fr. rejet) ”

“ A single normal fault of large throw is sometimes replaced by a series of close parallel faults, each throwing a small amount in the same direction; if these subordinate faults occur within a narrow width of ground they are known as distribution faults; if they are more widely separated they are called step faults (fig. 9) . Occasionally two normal faults hade towards one another and intersect, and the rock mass between them has been let down; this is described as a trough fault (fig. 10) . A fault running parallel to the strike of bedded rocks is a strike fault ”