UTAH PENEPLAINS 
121 
Because of the light which they recently shed upon the physio¬ 
graphic development of the arid part of our continent the High 
Plateaux of Utah possess unusual interest. Strangely, they give 
clue to the origin both of the bare desert ranges to the west of 
them, and to the forest-clad chains to the east. Arid Great Basin 
and pluvial Cordillera thus really evolve along parallel lines. The 
Utah heights not only connect the mountains of two climatic 
contrasts, but they carry westward the regional diastrophic record 
so clearly decipherable in the east, and indicate a succession of 
geographic cycles which the Great Basin has no doubt passed 
through, but of which it has now no other intimations. 
When the High Plateaux first became the subject of especial 
description, in the early eighties of the last century, the possibil¬ 
ity of a definite geographic cycle in land sculpture was one of the 
modern earth concepts not yet even faintly adumbrated. Omis¬ 
sion of such basic consideration, as it later proved to be, led 
necessarily to curious aberation in the treatment of the relief 
phenomena presented. 
As an ardent devotee of the Federal Geological Survey of that 
day, but following too closely perhaps the Powellian policy of 
geological saisissement, and carrying too joyously a soldier’s love 
for dramatic situation into scientific realms where it was out of 
place. Captain Dutton, upon whom devolved the exploration of 
this region, entirely missed the larger physiographic significance 
of his really fundamental observations on the prodigious erosion 
which the Utah field had manifestly undergone in recent geologi¬ 
cal times. He easily fell into idle speculations along entirely 
unrelated lines. Principal among the latter was an estimate of 
the crustal effects of sedimental loading and unloading through 
erosion. This unbridled fancy colored all his brilliant musings, 
and even distorted his striking conclusions out of all semblance to 
realities. 
Reverting to the long forgotten argument of Hershel, the Eng¬ 
lish astronomer, that areas of sedimentation should be tracts of in¬ 
sinking of the earth’s crust, the endeavor was to show that the 
converse of this assumption was also true, and that the Utah and 
Nevada regions from which such enormous volumes of rock-waste 
had been so recently removed, should display conspicuous evidences 
