TEE AGE OF THE DOMES AND ANTICLINES 307 



transverse direction to that of the Rawlins uplift and a parallelism 

 to the Ferris-Seminoe line of deformation. The O'Brien Springs 

 anticline, still farther south, shows a similar trend. 



From the considerations above set forth it seems reasonable to 

 suppose that the minor transverse folding in the Lost Soldier-Ferris 

 district on the Rawlins uplift was produced by compressive forces 

 that came from the direction of the Sweetwater uplift, to the north; 

 and from the parallelism between these folds and the Ferris- 

 Seminoe line of deformation, it seems reasonable to suppose further 

 that these minor folds represent the more distant effects of the same 

 forces that formed the Ferris and Seminoe mountains. 



2. If the truth of the preceding arguments is conceded, there 

 remains, to complete the purpose of this paper, proof that the 

 minor folds of the Lost Soldier-Ferris district are decidedly younger 

 than the major Rawlins uplift and the main development of the 

 Sweetwater uplift. It has been shown that the axes of the minor 

 folds are transverse to those of the Rawlins uplift, a relation which 

 in itself implies, although it does not necessarily prove, that the 

 minor folds are more recent than the uplift itself. The best proof, 

 however, is to be found in showing that the Ferris and Seminoe 

 mountains, which are of the same age as the minor folds of the 

 Lost Soldier-Ferris district, are considerably younger than the 

 main development of the Rawlins and Sweetwater uplifts. 



The Ferris and Seminoe mountains may be spoken of as a 

 marginal rim to the Sweetwater uplift. The central core of this 

 uphft, now represented by deeply eroded granite, is a structurally 

 much more highly elevated part of the uplift than the Ferris and 

 Seminoe mountains at its margin. It is possible that at the time 

 of the main deformation the central core of this major uplift was 

 elevated to several times the height of the marginal rim; but the 

 particular fact to be noted is that the Ferris and Seminoe mountains 

 now attain a maximum altitude of 10,025 f^^t (as determined by 

 triangulation and vertical angles), a considerably higher altitude 

 than that of the peaks of the Granite Mountains, which now form 

 the core of the uplift, and whose highest point, Hayden Peak, is 

 reported by Hares^ to have an altitude of only 8,040 feet. This 



' C. J. Hares, "Anticlines in Central Wyoming," U.S. Geol. Survey Bull. 641 

 (1916), p. 234. 



