STRIKE FAULTS 



549 



effects depend upon the direction and throw of the fault and upon 

 the inclination of the beds. Strike faults repeat the outcrops, 

 bringing the beds 

 again to the surface ; 

 in a series of paral- 

 lel or step faults, a 

 given stratum has a 

 number of outcrops 

 greater by one than 

 the number of faults. 

 Thisrepetitionofthe 

 outcrop may be very 

 deceptive, when the 

 surface has been 

 planed down to one 

 uniform slope or 

 curve. In Fig. 106, 

 for example, the ob- 

 server might easily 

 be misled into be- 

 lieving that seven 

 seams of coal were 

 cropping out on the 

 hillside, whereas the 

 section shows that 

 there are only two 

 such seams, their 

 repeated outcrops 

 being due to fault- c 



ing. FIG. 105. — Effect of strike fault on outcrop. A, 



The repetitions of before faulting ; B, with fault scarp standing ; C, with 



1 1 both upthrow and downthrow sides denuded to a con- 



outcrop,suchashave tinuQus m (Drawn from a mode] by Sopwith>) 

 been described, oc- 

 cur when the throw, or amount of displacement, is moderate. Great 

 faults, displaced many thousands of feet, and with the upthrow 

 side planed away by denudation, will display entirely different 



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