Page:Popular Science Monthly Volume 69.djvu/424

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420
POPULAR SCIENCE MONTHLY
Fig. 3. Nearly Five Thousand Feet of Rock Strata. Opposite, a Wall a Dozen Miles Distant.

above sea level. The distance between the top walls is from three to fifteen miles, and does not accord with the reports and pictures of the early government expeditions to the region. From El Tovar Hotel and the Grand View one sees the cañon at its broadest stretch, where for more than fifty miles it is a dozen miles wide and is filled with buttresses and buttes, towering from two to five thousand feet above the river.

The rim of the northern wall presents a nearly horizontal line. But a bird's-eye view from the western end of the canon would show the country to the east to be divided into four plateaus, each dipping like cakes of ice in a river till met by its neighbor. The plateau north of the visitor at El Tovar Hotel is one of the blocks that has been raised highest and consequently has brought up the lowest rocks and exposed them to the corroding action of the river.

If with a high buzz-saw we could cut through the country from east to west for three hundred miles and could move out the section nearest us, we should see that the face of the cut opposite is composed of a, series of blocks higher towards the west and slipping down towards the east. What we are unable to do in this regard has in a manner been done for us, since for ages the Colorado River has been eating away and has exposed the outlines of the blocks and the various geological formations so plainly that they are easily distinguished.

Seated on the rim in some favorable spot, one sees the different formations spread out as clearly as if diagrammed in a text-book on geology. The Kaibab plateau, just to the north shows six or seven