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CHESTER R. LONGWELL 



characteristic feature in the vicinity of Muddy Peaks. Moreover, 

 the unusual relation of older strata to younger along the entire 

 north side of the mountain is strong evidence of the unity of the 

 block. The known portion of the overthrust plate, therefore, ex- 



FiG. 6. — Devonian limestone, at the north end of Muddy Peaks Basin. A 

 thickness of about 600 feet is shown. Gray Jurassic sandstone beneath the overthrust 

 appears at the left of the view. 



Fig. 7. — Close view of the overthrust contact. The hammer rests on the Jurassic 

 sandstone. Well-cemented breccia lies above the surface of overthrust. 



tends from the west side of the Muddy Peaks mass to Bluepoint, 

 a distance of nearly 18 miles, and from Piute Point to the south 

 side of White Basin, a distance of 10 miles. It is not possible to 

 estimate the original dimensions of the plate. An indication that 

 the movement affected a large area is given by the fact that the 

 stratigraphic displacement apparent in Muddy Peaks Basin is ap- 



