80 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



For a considerable distance along White Eiver, Wasatch beds crop 

 out on the south side, being a continuation of the more extensive devel- 

 opment farther north in Dr.'^^White's district. Although comparatively 

 subordinate in their occurrence, they are represented sufficiently to influ- 

 ence the general appearance of the southern banks of the river. Eroiu 

 there they extend upward into the valleys of a number of the White's 

 tributaries, but are soon covered by Green River beds on account of 

 their dip. Wherever they do reach over into my district their presence 

 is due to some stratigraphical disturbance, the main portion of which is 

 north of the river. At times these disturbances have been productive 

 of very decided changes in the orographical features of the region, 

 greatly confusing the regular system of subordinate ridges and valleys 

 that is so admirably developed farther south. There the regular dip 

 and the average homogeneousness of the strata has produced results 

 that might almost be regarded as schematical in their regularity, both 

 of forfu and distribution. As soon, however, as any disturbance of 

 this normal condition occurs, this almost ideal arrangement of elevations 

 and depressions at once disappears. Thus, while the topography of our 

 district — one of minimum disturbance — may serve as a model, that of 

 the one adjoining it at the north is by far more complicated. 



On White Eiver, near Station 40, is another extensive outcrop of the 

 Wasatch Group. It is the highest of the series that has been brought 

 to exposure by the main upheaval occurring in Professor White's dis- 

 trict. In preceding pages the occurrence of Colorado, Fox Hills, and 

 Laramie beds, successively, has been mentioned as existing at the same 

 locality, and we now have to add the last member thus disturbed from 

 its normal position to the list. From a distance already it had been 

 noticed that the strata exposed along Douglas Creek differed in general 

 appearance, color, and shape of hills from those surrounding them. 

 Upon examination it was seen that this was due to the existence of Wa- 

 satch beds at that locality. By virtue of the upheaval which has thrown 

 the entire lower series up, south of the river, the Wasatch, together with 

 the others, acquired a southerly dip. As the Green River strata were 

 raised at the same time, subsequent erosions produced an exposure of. 

 the former along the lowest portions of the Douglas drainage. 



The upheaval itself is a curious one. It has produced an approxi- 

 mately oval arrangement of hogbacks, composed of Fox Hills beds, 

 which dip olf from a definite center in every direction. Enclosed by them 

 is a nearly level valley containing Colorado shales. Outside of this inner 

 circle of hogbacks are several others, each one exhibiting the beds of 

 one of the succeeding higher strata. It is owing to this that we find 

 south of the river a concentric arrangement of strata grouped in accord- 

 ance with their geological age. Professor White will treat of this sub- 

 ject more fully, and I therefore refer to his report for information thereon. 



Ascending Douglas Creek we find the exposure of Wasatch beds on 

 either side. They gradually lose their southerly dip, become horizontal, 

 and finally dip northward until they once more disappear under the 

 heavy strata of the Green River Group. Here, too, in the bluffs and 

 the lower portion of caiions, the variations in color, as exhibited by the 

 strata, can be observed, although not so strikingly as in the locality 

 north of the Grand. More particularly one stratum can serve as a well- 

 defined and easily-recognizable horizon. This is composed of a bed of 

 sandstone, about 160 feet in thickness, of a brick-red color. It can be 

 traced from a distance for many miles along the creek, and serves as a 

 landmark for identification. At other localities, contiguous, however, it 

 was also noticed, and then, too, in the same relative position. 



