FORM OF THE DISPLACEMENT. 207 



larities, though amounting sometimes to hundreds of feet, are too small to 

 introduce any serious error in our conclusions. It is unnecessary to burden 

 these pages by a detailed presentation of the facts we have used in deducing 

 the form of the uplift; we will merely describe it Man} T of the facts are 

 recorded in the geographic and topographic maps and in the bird's-eye 

 view, and still others have been detailed in the descriptions of the forma- 

 tions in the earlier portions of the chapter. 



/The first important feature of the uplift is that it is flat-topped. It 

 belongs to the same order of displacement as the Uinta Mountains and the 

 Kaibab Plateau.* The top is not absolutely flat, but relatively so, and the 

 inclination all about the periphery is very much greater than any inclina- 

 tion upon the upper surface. The extent of this tabular top is shown on 

 the geological map by the combined outcrops of the Carboniferous and 

 Archaean. It is oval in form, with a length of seventy miles and a width of 

 forty. Its general trend is about 10° west of north, but its axis is not a 

 straight line; its eastern side is more strongly curved than its western, and 

 gives an impression, borne out by other evidence, that its median line has 

 a decided curvature, the concavity of which is toward the west. J The 

 highest part of the table is nearer the eastern edge than the western, and 

 it is perhaps true that the entire top slopes toward the west; certainly that 

 portion deduced from the study of the Carboniferous plateau does so. 



The descent from the tabular summit is steeper at the east and west 

 than it is at the north and south; that is to say, the table is more definitely 

 bounded at the sides than it is at the ends. On the east side the surface 

 bends over gradually until it acquires an inclination of about 30°, and then 

 curves still more gradually at the base of the uplift until it loses its incli- 

 nation and merges with the imperceptible slope of the strata of the Plains. 

 The same is true on the west side, with a single exception. At a point 

 near Camp Jenney the descent is, for a short distance, so steep as to be 

 almost vertical. 



At the south end the greatest inclination is not more than 15°, and the 

 curves which connect this with the table above and with the datum plane 

 below are exceedingly gentle. There is a sort of prolongation of the uplift, 



* Geology of the Uinta Mountains, J. W. Powell, pp. 11-17. 



