Page:Titan of chasms - the Grand Canyon of Arizona (IA titanofchasmsgra00atchrich).pdf/21

 southwest the wall rises abruptly from the water to the summit of the plateau for about 6,000 feet, but across the river on the north and west mountains of gneiss and quartzites appear, sometimes rising to the height of a thousand feet. These are mountains in the bottom of a canyon, The buttes and plateaus of the inter-canyon region are composed of shales, sandstones, and limestones, which give rise to vast architectural shelving and to pinnacles and towers of gigantic proportions, the whole embossed with a marvelously minute system of fretwork carved by the artistic clouds. Looking beyond these mountains, buttes, and plateaus vistas of the walls of the great plateau are seen. From these walls project salients, and deep re-entrant angles appear.

The whole scene is forever reminding you of mighty architectural pinnacles and towers and balustrades and arches and columns with lattice work and delicate carving. All of these architectural features are sublime by titanic painting in varied hues—pink, red, brown, lavender, gray, blue, and black. In some lights the saffron prevails, in other lights vermilion, and yet in other lights the grays and blacks predominate. At times, and perhaps in rare seasons, clouds and cloudlets form in the canyon below and wander among the side canyons and float higher and higher until they are dissolved in the upper air, or perhaps they accumulate to hide great portions of the landscape. Then through rifts in the clouds vistas of Wonderland are seen. Such is that portion of the canyon around the great south bend of the Colorado River past the point of the Kaibab Plateau.

As Seen by the Geologist

Tn the last chapter of my book entitled “The Canyons of the Colorado” I have described the Grand Canyon in the following terms:

‘The Grand Canyon is a gorge 217 miles in length, through which flows a great river with many storm-born tributaries. It has a winding way, as rivers are wont to have. Its banks are vast structures of adamant, piled up in forms rarely seen in the mountains.

Down by the river the walls are composed of black gneiss, slates, and schists, all greatly implicated and traversed by dikes of granite. Let this formation be called the black gneiss. It is usually about 800 feet in thickness.

Then over the black gneiss are found 800 feet of quartzites, usually in very thin beds of many colors, but exceedingly hard, and ringing under the hammer like phonolite. These beds are dipping and unconformable with the rocks above. While they make but 800 feet of the wall or less they have a geologic thickness of 12,000 feet. Set up a row of books aslant; it is ten inches from the shelf to the top of the line of books, but there may be three feet of the books measured directly through the leaves. So these quartzites are aslant, and though of great geologic thickness they make but 800 feet of the wall. Your books may have many-colored bindings and differ greatly in their contents; so these quartzites vary greatly from place to place along the wall, and in many places they entirely disappear, Let us call this formation the variegated quartzite.

Above the quartzites there are 500 feet of sandstones. They are of a greenish hue, but are mottled with spots of brown and black by iron stains. They usually stand in-a bold cliff, weathered in alcoves, Let this formation be called the cliff sandstone.

Above the cliff sandstone there are 700 feet of bedded sandstones and limestones, which are massive sometimes and sometimes broken into thin strata. These rocks are often weathered in deep alcoves, Let this formation be called the alcove sandstone.

Over the alcove sandstone there are 1,600 feet of limestone, in many places