WHITE.] DISPLACEMENTS. 47 



side of this uplift, which I have called the Eaven Eidge Flexure, is much 

 more abrupt than that of the northern side. This is also a peculiarity 

 of the eastern prolongation of the Midland Uplift, the southern flexure 

 of which is a part of the Great Midland Flexure, and also of the western 

 portion of the Danforth Hills TJi)lift, presently to be described. In short, 

 it is a common peculiarity of the flexures that are embraced within the 

 sweep of the eastward extension of the Axial Uplift, as it extends from 

 the Unita system to join with the Park Eange system; but it is not a 

 peculiarity of the Axial Uplift itself, which has a nearly uniform curva- 

 ture or flexure from side to side. The significance of the greater abrupt- 

 ness of the dip upon the southern side of these secondary uplifts is, no 

 doubt, to be sought in the forces which have acted laterally as well as 

 vertically in the elevation of the two great ranges of mountains, at least 

 within the angle formed between the two within this district. 



The dip of the strata is in all directions from the middle of Eaven 

 Park, but it varies much in degree in diflerent directions. It is very 

 slight to the northward and westward, not reaching so much as 10 de- 

 grees, while in the Eaven Eidge Flexure, at the south side of Eaven 

 Park, the dip is as much as 60 degrees, from which point it diminishes 

 both eastward and westward, until the uplift, as such, finally disappears. 



The Danforth Hills Uplift. — Eastward from the eastern end of the 

 Plateau and Midland uplitts, and between them and the displacements 

 that are more properly referable to the Park Eange system, there is a 

 broad, irregular syucliual, which is occupied by the strata of the Wa- 

 satch and Green Eiver groups, of Tertiary age. The depth and impor- 

 tance of this synclinal is shown in one of the sections at the bottom of 

 the accompanying geological map. Its importance still further appears 

 by the fact that the difference of displacement between the top of the 

 Green Eiver strata which rest upon it and that of the Carboniferous 

 strata that are exposed in the uplifts and upthrusts that have been de- 

 scribed, the latter of which are less than half a dozen miles from its 

 borders, is more than 10,000 feet. This great synclinal is partly sur- 

 rounded by an outcrop of the strata of the Fox Hills and Laramie 

 groups, which are upturned by the Midland Flexure as it traverses by 

 a tortuous course almost the entire length of the district. Adjoining 

 the northern side of this broad synclinal is the Danforth Hills Uplift, 

 which, although a comparatively slight one, derives peculiar interest 

 from the fact that it is so intimately connected with the displacements 

 of both the neighboring mountain systems that it cannot be exclu- 

 sively referred to either. The displacement of strata involved '.n this 

 uplift upon its northern, or rather northeastern, side is comparatively 

 slight, because they connect by a very gentle synclinal with those that 

 have been still more elevated by the Axial Uplift, and the general rise 

 of all the strata of the district toward the foot-hills of the Park Eange. 

 The displacement at the southern side of this uplift, however, is very 

 great, the drop, of the Midland Flexure there being not only very ab- 

 rupt, but it amounts to more than 3,000 feet. 



The Danforth Hills Uplift is bounded on its southeastern side by the 

 Midland Flexure, its other boundary being a gentle synclinal that ex- 

 tends eastward from the point of junction of the Midland Flexure with 

 that of the Great Hogback, in Hogback Valley, and sweeps around, but 

 within, the entire eastern end of the Danforth Hills, and thence north- 

 westward along their northern slope, fading out in the vicinity of Yampa 

 Mountain, where the uplift as a separate displacement also disappears. 



/Sundry uplifts. — Besides the uplifts that have been specially described 

 on preceding pages, certain portions of others reach within the boun- 



