John Wesley Pon'cll— Merrill. 331 
tains, which was pubhshed in 1876. In this, as in all the 
work of the Powell surveys, little or no attempt was made 
at systematic areal geology ; certain striking and well-ex- 
emplified features were selected and made the subject of 
special monographs. In the work above noted Powell di- 
vided the region west of the Great Plains, east of the Sierra 
Xevadas, and south of the North PSatte, Shoshone, and 
Sweetwater rivers, into what he designated as geological 
provinces, the Park province, the Plateau province, and the 
Basin province. The first named he described as character- 
ized by broad, massive ranges, sometimes distinct and some- 
times coalescing so as to include the great parks. The moun- 
tains comprise high, lofty, snow-clad peaks which form per- 
ennial reservoirs for the multitude of streams discharging 
in part into the Colorado river and thence into the Gulf of 
California,, and in part into the Rio Grande and thence into 
the gulf of Mexico. The Plateau province he described as 
characterized by many tables bounded by canon and clifif 
escarpments and on wdiich stand lone mountains and irregu- 
lar groups of mountains and short ranges. This region drains 
wholly into the Colorado river. The Basin province was 
characterized by short north and south mountain ranges and 
ridges separated b}' desert valleys and with a drainage which 
is almost wholly into the interior salt lakes and sinks. 
Devoting himself mainly to the Uintahs, Powell showed 
that they owed their present configuration to the degradation 
of a great upheaved block having its axis in an east and west 
direction. This upheaval, w^hich he thought took place very 
slowly and gradually, began at the close of Mesozoic time 
and continued with slight intermission until late Cenozoic. 
The total amount of upheaval in the axial region was more 
than thirty thousand feet. Contemporaneous with upheaval 
the forces of degradation were at work, though not at the 
same rate of progress, along the axial line of uplift, the de- 
gradation amounting to more than twenty-five thousand feet 
(4^ miles) and the mean degradation to 35^2 miles, so t'.iat, 
over the entire area of about 2,000 square miles, some 7,100 
cubic miles of material has been removed. 
During 1873, 1875 ^^"^^ i^y6 captain Clarence Dutton of 
the Ordnance Department of the U. S. Army, made further 
