VOLCANIC PHENOMENA. 
95 
wide fields, liave reached the brink of the inner gorge. Pouring over its 
brink, the fiery cascades have shot down into the abyss and pursued their 
way many miles along the bed of the river. At one epoch they had built 
up the bed of the Colorado about 400 feet, but the river has scoured out 
its channel again and swept them all away, regaining its old level, and is 
now cutting the sandstones below. The spectacle of the lava floods descend- 
ing from the Uinkaret, as seen from Vulcan’s Throne, is most imposing. 
It tells the story so plainly that a child could read and understand it. 
Compared with many classic volcanic regions the volcanism of the Uinkaret 
is a small affair. But in those classic regions the mind does not come into 
direct contact with the enormity of the facts by a single glance of the eye. 
But here, if kind Asmodeus were to lift the basaltic roof of the plateau, we 
should see no more than we do now. The boldness of the picture is much 
increased by the pediments of Carboniferous strata projecting from the 
body of the plateau, showing the brilliant colors of the strata and their 
sharply defined architecture, with the dark masses of basalt wrapping 
around them. Hard by, and almost within hail, is a superb gable project- 
ing between two broad floods of lava, and so beautifully proportioned and 
richly colored that we cannot help wishing to transport it by magic to some 
more habitable region. 
Turning now to the southward and looking across the inner gorge to 
its opposing wall, a strange spectacle of havoc and wreck is presented to 
our view. A lateral gorge or amphitheater is excavated in the chasm wall, 
very nearly as deep as the main abyss. Here the action of volcanic forces 
is displayed in a manner which is quite unique. At the summit of the wall 
of the inner gorge, just at the angle where it swings backward into the 
amphitheater, a ruined basaltic crater stands upon the very brink. Indeed 
its lower portions on two sides are undermined by the falling of the wall, 
and the anatomy of the cone is laid open to view. And not only that, but 
the very dike through which the lava came up is disclosed to a depth of 
half a mile. There are also other dikes which show their edges in the 
wall of the amphitheater in transverse vertical section, and which outcrop 
in the main wall of the gorge (Fig. 2). The strike of these dikes is parallel 
to the river. One of them protrudes from the sloping front of the wall 
