UTAH ACADEMY OF SCIENCES 39 
Eldridge, who base their classification on the Orogenic 
Movements in the Denver Basin, are placed in the Lower 
Cretaceous. If the latter classification is right, then these 
beds are the only ones in the Western Interior Region that 
belong to the Lower Cretaceous as known from the typical 
localities. 
EROSIONAL FEATURES. 
I shall now give the erosional features of the three 
series as I have outlined them. The massive five hundred 
feet of sandstone of the first or Lower series forms per- 
pendicular cliffs with exceedingly smooth faces. Because 
of the absence of joint planes there are no rocky talus slopes 
to cover the underlying Triassic strata. These straight 
walled cliffs are everywhere capped with pinnacles, domes, 
and beehives, which belong to the upper five hundred feet, 
and are the results of the elements on the intricately cross- 
bedded structure. The effect of wind erosion on this cross- 
bedding is most peculiar. Great caves or alcoves, as they 
may be called, are worn out of the face of the cliffs, their 
walls as smooth and round as if done by the hand of man. 
In other places are worn hundreds of smaller holes, about 
from a few inches to three or four feet in diameter and 
very close together. This gives the appearance of a huge 
honeycomb, only lacking the bees to make the comparison 
complete. 
Wherever a stream has cut its way through this sand- 
stone the walls are vertical and the canyons are very tor- 
tuous. A characteristic bit of weathering is found in the 
North Salt Wash, Emery County. Following the wash 
one comes up against a straight wall seven hundred feet 
high. Near the top is a hole through which the blue sky 
shows like a mirror. The canyon then turns abruptly to 
the east and after a detour of some five miles the hole is 
again seen from the other side, not over a mile and a half 
from the first observation point. This winding back and 
forth with very little progress in a straight line is charac- 
teristic of all canyons in this stratum and the parapets and 
