Subsurface Maps and Illustrations 



903 



fault, and the lower numbers (in parenthesis) are elevations of the fault 

 plane. As in A of figure 477, the productive area is ruled. 



The curving of the datum contours beneath the thrust sheet, north- 

 west of the "hidden" syncline, suggests that some folding had taken place 

 prior to the faulting; therefore, the possibility of accumulation of oil in the 

 upper edge of the faulted flank beneath the fault might be anticipated, 

 if the upturned edge of the reservoir had been adequately sealed by the 

 fault. 



Figure 476. Structural contour map showing a datum (fault) gap 

 and the contoured fault plane. 



