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ARTHUR BEVAN 



same orogenic epoch. Inasmuch as the fault plane is not exposed 

 and remnants of overthrust beds, if ever present, have not been 

 preserved beyond the eastern base of the range, the amount of 

 horizontal displacement along the Beartooth front is indeterminable. 

 In view of the enormous displacement at Heart Mountain beyond 

 the southeastern end of this range, it is not improbable that the 

 maximum displacement along the Beartooth fault plane was at 

 least several miles, though this is not an absolute corollary. 



Fig. 12. — The Clark Fork fault (?) along the southwest side of the range. Pre- 

 Cambrian granite in the foreground, overlain by horizontal Cambrian in the distance. 

 Range in background is of pre-Cambrian granite. 



The Clark Fork fault ( ?) . — The extreme southwest flank of the 

 range, along the northeast side of Clark Fork Canyon, appears to 

 be bounded by a considerable fault of the gravity (or "normal") 

 type. A rapid reconnaissance trip in stormy weather permitted 

 only a cursory inspection of the geology of this area, but the bold 

 escarpment that here rises abruptly to the western rim of the sub- 

 summit plateau is strongly suggestive of a fault. The topographic 

 evidence is well shown on the topographic maps,^ although no fault 



' Crandall, Wyoming, quadrangle and the advance sheet of Part of the Shoshone 

 National Forest, Wyoming. 



