272 DESCRIPTIVE GEOLOGY. 



teau region about 8,000 feet above sea-level, surrounded on the east, north, 

 and west by irregularly-distributed peaks and rounded hills, rising from 

 1,000 to 2,000 feet above it. The forest-covered hills between the heads 

 of Willow Creek and of the Eastern Branch of Red Creek, overlooking the 

 plateau from the west, are formed of drab limestones of the Upper Coal-Meas- 

 ure group, dipping 50° to the northward, with a general east and west strike. 

 .Under these, to the south, are found the red sandstones and quartzites of 

 the Weber group, conformable in dip, but gradually flattening out to the 

 southward, until, on the edge of the cliffs which overlook Brown's Park, at 

 the canon of Beaver Creek, for instance, they have a dip of only 5° nortli. 

 This is the general structure of the plateau, namely, on its southern border 

 overlooking Brown's Peak, consisting of beds of the Weber Quartzite, lying 

 nearly horizontal, or with a slight dip northeastward, though, in one instance, 

 at a projecting point near the eastern end of the cliffs, a local dip of 8° to 

 the southward was observed. The general surface of the plateau is too 

 much covered with soil and trees to afford good continuous sections. Along 

 the open valley at the northern portion, between the heads of Talamantds 

 and Red Creeks, however, these same beds are found standing at angles of 

 50° to 60° north, with a strike of nearly east, which toward the eastern end 

 bends to southeast. The change, in dip between the interior of the fold and 

 its flanks, is even more abrupt and considerable than that already observed 

 farther west, and points, as has already been remarked, to a continuation of 

 the fault-line developed north of the Archaean body. It seems probable, 

 also, that the whole region bordering Brown's Park has suffered subsidence 

 since the formation of the main Uinta fold. Of the elevations bordering the 

 plateau on the- north and east, that next west of Diamond Peak, as well as 

 could be distinguished under its forest-covering, was formed of nearly hori- 

 zontal beds of the Vermillion Creek Tertiary, capped by the Wyoming Con- 

 glomerates. Diamond Peak itself, so called from the reputed discovery of 

 diamonds along its northern slopes, which gave rise to the diamond bubble 

 of 1872, is composed of drab limestones and sandstones of the Upper Coal- 

 Measure group, easily recognized by their position and lithological character, 

 though no fossils were found here by our parties. The beds are much 

 broken, and the structure consequently somewhat obscure. Dips of 25° 



