2 
THE GRAND CASfON DISTRICT. 
anywhere between 13,000 and 16,000 square miles. The Colorado River 
of the West runs across the middle of the district in a very tortuous course, 
averaging west-southwest. Its valley is the Marble Canon and Grand 
Canon.* That part of the district which lies south of the river has been 
reconnoitered but not thoroughly studied. Its broader geological features 
are in great part known, but its details remain to be worked out. The por- 
tion which lies north of the river has been studied in considerable detail. 
Upon the northern side six subdivisions may be recognized. Upon the 
extreme north is a series of terraces carved by erosion out of the Mesozoic 
and lower Eocene strata, which, covering all the region of the High Pla- 
teaus, suddenly terminate in a succession of high cliffs, dropping step by 
step to lower and lower formations, like a great stairway. At the foot of 
the stairway is the comparatively smooth platform of the summit Carbon- 
iferous, which stretches southward and southeastward into central Arizona 
for 150 miles or more. The “Terraces” form one subdivision, and are a 
border country between the High Plateaus on the north and the Grand 
Canon district on the south, and may be regarded as the appanage of either 
district. The main Carboniferous platform north of the river may be sub- 
divided. into five distinct plateaus. On the west is tlie Sheavwits Plateau ; 
next in order towards the east is the Uinkaret; the third is the Kanab Pla- 
teau, the fourth is the Kaibab, and the fifth is the Paria Plateau. 
The dividing lines between these plateaus are well marked, consisting 
of great faults or equivalent monoclinal flexures, trending north and south. 
The westernmost fault bounds the Sheavwits Plateau as well as the district 
itself, and is named the Grand Wash fault. Beyond it, to the westward, is a 
region having features very similar to those of the Great Basin of Nevada. 
Next in order towards the east are the Hurricane and the Toroweap faults. 
Between the last two is the Uinkaret Plateaii. Passing across the Kanab 
platform we reach the Kaibab, which is hoisted to a greater altitude than 
the others, with the West Kaibab fault on one side and the East Kaibab 
*TMs name has been repeatedly infringed for purposes of advertisement. The canon of the Yel- 
lowstone has been called “The Grand Canon.” A more flagrant piracy is the naming of the gorge of 
the Arkansas River in Colorado “The Grand Canon of Colorado,” and many persons who have visited 
it have been persuaded that they have seen the great chasm. These river valleys are certainly very 
pleasing and picturesque, hut there is no more comparison between them aud the mighty chasm of the 
Colorado River than there is between the Alleghenies or Trosachs and the Himalayas. 
