262 



GRAVITATIONAL METHODS 



[Chap. 7 



Above an extended slope (see Fig. 7-99) loge — = and ^2 — vi — t 



so that 



Ux'z — k8ir sin 2i ] 



(7-93d) 

 — C/a' — 2A;67r sin i. 



(g) 



Fig. 7-99/-2. Gradients and curvatures for two-dimensional features, continued 

 (after Jung). G = Gradient, K = curvature value. 



For small angles sin i ^ i; therefore, the gradient on extended slopes is 



l\'^ = 2k87ri = 7.381° E.U., (7-93e) 



which is a useful formula for correlating regional dip and regional gradient. 

 In all these formulas, 8 signifies, of course, difference in density. If i is 

 expressed in radians, the coefficient in eq. (7-93e) is 419 E.U. 



