5.0 Contour inlerval = 2 m g 10 



Contour interval =0.2 m g. 



Figure 572. Observed-gravity contours over Altus field, Jackson County, Oklahoma 

 (above) ; residual contours below. Contour interval 0.2 milligals. Producing area 

 outlined. (After Coffin. Reproduced permission Am. Assoc. Petroleum Geologists.) 



