188 



EXPLORATION GEOPHYSICS 



If the dipole is inclined (Figure 80), Equations 70 and 71 must be 

 modified to include the cosine of the dip of the ore body and its length. 

 It may be shown from an analysis similar to that given for the vertical 



X / 



Fig. 80. — Sketch illustrating geometric relations 

 of dip of ore body and vectors ri and rz to the 

 point of observation F on an .«■ traverse. 



dipole that the expressions for the vertical and horizontal intensity 

 anomalies along the ,r-axis are : 



AZ = 





di di + I sin i 



AH = — m ~ — 



] 



[X X — I cos i ~j 



(72) 

 (73) 



where d\ is the depth to the top of the ore body; and (di + /sin i) — d<2, is 

 the depth to the bottom of the ore body ; ri and r^ are the distances from 

 the point of observation to top and bottom respectively ; / is the length and 



Fig. 81. — Vertical and horizontal 

 intensity anomalies for an inclined 

 doublet. 



