BASALTS OF THE UINKAEET. 
107 
escarpment of the Uinkaret across the branches of the Hurricane fault, and 
have reached to the bottom of the Queantoweap Valley, more than 3,000 
feet below. These coulees lie across the scarped wall of the old lava-cap, 
which had been greatly eroded and wasted before the younger floods were 
outpoured. The relation of the younger basalts of the Emma platform 
overlying the older ones is therefore exceptional, as compared with the 
relations of the two groups of lavas presented in Trumbull and Logan. 
The inferences to be drawn from these facts are as follows. During 
the eruption of the older basalts the Uinkaret Plateau had a very different 
topography from the present. It is probable that at that epoch very large 
bodies of Permian strata, some of them embracing the entire series, 
remained, and not only covered the greater part of the plateau, but may 
have sustained important remnants of the Trias. It is useless to speculate 
as to details, or even as to the broader features of that ancient topography. 
The conclusion is limited to the inference that the Permian formation then 
constituted the general platform in much the same way as the upper 
Carboniferous now does. It is a fair presumption that the plane of contact 
between the lava-caps of Trumbull and Logan, and the Permian beds 
beneath, represents the approximate geological horizon whicli then consti- 
tuted the surface of the region. In one place higher strata may have 
occurred, in another some progress may have been made in the denudation 
of the Permian. The remnants of this formation, now found in Trumbull 
and Logan, owe their preservation to the thick coverings of basalt. 
On the Sheavwits Plateau we find a precisely similar state of facts. 
About 12 or 15 miles northwest of Logan is a large remnant of Permian 
beds overlaid with basalt. It has received the name of Diamond Butte. It 
rises 800 to 900 feet above the surrounding plain, and discloses the edges of 
the strata lying almost horizontally and showing their characteristic colors. 
Far beyond it, in the northern part of the plateau, may be discerned the 
cliffs bounding the principal mass of this formation. Turning to the south- 
east of Logan, we may perceive a much larger mass of the same nature 
situated in the southern part of the Sheavwits. It consists of Permian 
strata covered with basalt. The length of this outlier is about 25 miles 
and its width from 3 to 3 miles. Whether the entire Permian series is 
