208 GEOLOGY OF THE niGH TliATEAUS. 



uniformity over miles of exposure and contrasting with each other by their 

 varying shades of chocolate, dark red, and purple, producing an effect of 

 colored bands of small thickness individually but great collectively, and 

 with a perfect regularity or parallelism. (See Heliotype No. XI.) 



The Lower Mesozoic series (Jura and Trias) is found in the Markdgunt 

 only in the immediate vicinity of the great Hurricane displacement, which 

 defines the western boundary of the structure, and is only seen there along 

 the southern portion of the west flank. I have not visited them, but Mr. 

 Howell has examined them somewhat cursorily, and the results of his 

 observations, in the form of notes, are before me. There is a general agree- 

 ment of the sections he there found with the general section of the Plateau 

 Country to the eastward, though there are minor differences which might 

 be worthy of future study. All of the notable Mesozoic groups and beds 

 are present and seem to be on the whole somewhat thicker than they are 

 to the eastward, but the thickness is more variable and the deposition 

 generally more unequal. In close proximity to the great fault, the beds 

 are in some places flexed abruptly upwards on the uplifted side of the fault, 

 but in passing eastward they speedily recur to the general east or east- 

 northeast dip of 1° to 2° which prevails throughout the plateau. Nowhere 

 in this vicinity does the Carboniferous seem to be exposed, though in 

 several localities it must be very near the surface in the immediate line of 

 the fault. Where these upward flexures occur, the plane of denudation 

 between the summit of the plateau and the fault cuts across the entire 

 series of Mesozoic and Cenozoic formations more than 10,000 feet in thick- 

 ness. 



From the southwest salient of the Markdgunt we behold one of those 

 sublime spectacles which characterize the loftiest standpoints of the Pla- 

 teau Province. Even to the mere tourist there are few panoramas so 

 broad and grand; but to the geologist there comes with all the visible 

 grandeur a deep significance. The radius of vision is from 80 to 100 

 miles. We stand upon the great cliff of Tertiary beds which meanders to 

 the eastward till lost in the distance, sculptured into strange and even 

 startling forms, and lit up with colors so rich and glowing that they awaken 

 enthusiasm in the most apathetic. To the southward the profile of the 



