or 8 or 10 miles below the mouth of the Little Colorado, the river is
in the variegated quartzites, and a wonderful fretwork of forms and
colors, peculiar to this rock, stretches back for miles to a labyrinth
of the red wall cliff; then below, the black gneiss is entered and soon
has reached an altitude of 800 feet and sometimes more than 1,000 feet;
and upon this black gneiss all the other structures in their wonderful
colors are lifted. These continue for about 70 miles, when the black
gneiss below is lost, for the walls are dropped down by the West Kaibab
Fault, and the river flows in the quartzites.

Then for 80 miles the mottled, or alcove, sandstones are found in the
river bed. The course of the canyon is a little south of west and is
comparatively straight. At the top of the red wall limestone there is a
broad terrace, two or three miles in width, composed of hills of
wonderful forms carved in the banded beds, and back of this is seen a
cliff in the tower limestone. Along the lower course of this stretch the
whole character of the canyon is changed by another set of complicating
conditions. We have now reached a region of volcanic activity. After the
canyons were cut nearly to their present depth, lavas poured out and
volcanoes were built on the walls of the canyon, but not in the canyon
itself, though at places rivers of molten rock rolled down the walls
into the Colorado.

The next 80 miles of the canyon is a compound of that found where the
river is in the black gneiss and that found where the dead volcanoes
stand on the brink of the wall. In the first stretch, where the gneiss
is at the foundation, we have a great bend to the south, and in the last
stretch, where the gneiss is below and the dead volcanoes above, another
great southern detour is found. These two great beds are separated by 80
miles of comparatively straight river. Let us call this first great bend
the Kaibab reach of the canyon, and the straight part the Kanab reach,
for the Kanab Creek heads far off in the plateau to the north and joins
the Colorado at the beginning of the middle stretch. The third great
southern bend is the Shiwits stretch. Thus there are three distinct
portions of the Grand Canyon of the Colorado: the Kaibab section,
characterized more by its buttes and salients; the Kanab section,
characterized by its comparatively straight walls with volcanoes on the
brink; and the Shiwits section, which is broken into great terraces with