182 H. F. REID GEOMETRY OF FAULTS 



line ed, will be the projection of the point where the fault-plane, the 

 stratum, and the dike met before the disruption. In the same way we 

 find /', the projection of the meeting point after disruption; ff' will be 

 the projection of the total shift. /' g m is the depth of the original of /'; 



Figure 8. — Determination of the Shift, Case II 



fg iy = fg is the depth of the original of f; hence g lv g m is the total 

 amount of the shift and fkg iv is its inclination. The actual movement 

 is known and all displacements can be immediately found. In this case 

 the point of the stratum, T , at the original of / before disruption, moved 



