VERTICAL AND INCLINED SURFACES OF SEPARATION 



279 





Fig 5. a — approximately constructed curves for p2 ^ (&i fc)L' ^ — approximately 

 constructed curves for q^ < (?i \ilL.'^ '^ — VEP curves for a horizontally homogeneous 

 medium; d — line connecting the points on VEP curves for the maximum separations 

 of AB used in practical work. 



The deviation of q^ ^^^ from (^^ ^^ of the minimum is insignificant for 

 distances d being greater or smaller than the abscissa of the minimum. 



The maximum deviation on the VEP curves in the cross-section under 

 consideration is observed when d — H. The observed deviation can be 

 largely utilized for qualitative evaluation of the depth at which a reflecting 

 horizon is lying. 



Fig 6. a — approximately constructed J_ VEP curves ; 6 — approximately constructed 

 1 1 VEP curves; c — VEP curves for a horizontally homogeneous medium. 



