346 



EXPLORATION GEOPHYSICS 



+ 3 



+ 3 







- 7 

 -12 

 -15 

 -12 



- 7 

 



+ 3 

 + 3 



Some published examples of curvature quantity profiles have the 

 plotting in reverse from that described, with the maximum plus values 

 over the structural crest. This would be graphically equivalent to rotat- 

 ing the R-line profile (in Figure 197) 180° about the profile axis. 



PROF I UE 



STATIONS 



-10 

 -li- 



PLAN VIEW 



■=-^-|-|-h|-l-/-" 



Fig. 197. — Profile of curvature quantity (R-line value) across an 

 anticline. Data is shown for angle \J> of R-line with line of profile and 

 for \R\, the magnitude of the R-line value in Eotvos units, (£). 



The magnitude of the curvature quantity at a given station is propor- 

 tional to the gravity value at the station and to the amount of the difference 

 in the curvature of equipotential surfaces as they reflect subsurface condi- 

 tions. This is expressed in Equation 27. For this reason the largest R-line 



