A Canyon is Born

Almost every visitor to the Grand Canyon, after he has recovered from the shock of the first look, wants to know two things: "When did this happen-and what caused it?"

The answers are simple: It happened twelve million years ago; the river did it.

And the visitor, quite properly, is not satisfied. He And the visitor, quite properly, is not satisfied. He wants to know more, and unless he has some knowledge of geology it is not likely that it will ever be very clear to him. To fill this want, the National Park Service has provided a series of lectures, and nature walks, and charts and maps and models, and a library, and a museum. They are all excellently managed, and a visitor who has never heard of geological eras and periods will begin to see daylight if he attends a few talks, and thinks about what he has seen and heard. Nature has prepared a mighty A Canyon Is Born is a chapter from Edwin Corle's entertaining and comprehensive book about the region of the Grand Canyon. Listen, Bright Angel. It is reprinted here by gracious permission of the publishers, Duell, Sloan and Pearce, New York. The late Edwin Corle is one of the West's foremost authors. Among his books which should not be neglected by readers interested in the West are: Mojave, The Gila, Desert Counry, Burro Alley, Billy the Kid. The Royal Highway, and Coarse Gold.

Drama. At your feet is the amazing and thrilling story of the history of the earth and the life that populates it. A sensitive mind will be excited, awed, and moved. A great artist is there to perform for you if you will but take it in. You will never be quite the same again to your advantage. Theodore Roosevelt said that the Grand Canyon was something that every American ought to see. He might have expanded the remark to include everybody on earth. Just seeing it is not quite enough; people ought to understand it. Some do; some don't. But the Park Service is making it easy for those who have a genuine desire to know more. As we have seen, there was a time when the Grand Canyon didn't exist. This may have been twelve million years ago-or it may have been as much as a hundred million. Since man himself has been on earth only one million years, there are no witnesses as to just when the erosion process of canyon cutting began, or just when the first little trickle of water began to wear its path into the Kaibab limestone. Scientists agree, in general, that twelve to fifteen million years ago would be a fair estimate. One thing is certain, and that is geological history. The earth built up its steady system of sedimentary deposits up to the last geological era. Then it contrived to wear away the recent strata back to the Permian period. Here it stopped the great denudation. A broad flat plain of limestone existed. A little stream ran west across the plain. Slowly the force that raised the blister on the earth at this spot raised it again. The little stream dug in deeper, and although the limestone plain sloped toward the south, the little stream refused to be thrown from its channel by this tilt. This slope of the land to the south meant, however, that most of the tributaries of the stream would come from the north. Water didn't run uphill, even twelve or fifteen million years ago. The gash that was cut into the limestone may have been two inches deep. If so, it was probably several inches across. This was the Grand Canyon in its infancy and the little stream was the Colorado River. It is still cutting that gash deeper and wider today and will still be cutting it centuries hence. Today it is a mile deep and varies from ten to twelve miles across at the rim. As the water erosion and canyon cutting continued, the stream began to turn backwards the pages of geological history. It cut all the way through the Kaibab limestone and hit the Coconino sandstone beneath. This meant that it was a huge canyon, for the limestone goes down into the earth for five hundred and fifty feet. It cut through the underlying soft sandstone and into the Hermit shale. The canyon was then over eleven hundred feet deep. Two Washington Monuments, one on top of the other, would barely have reached the rim from the river. This was nothing to what was to come. The river, at this time, must have been about as large as it is today. Wind erosion was helping to recess the side walls. A great earthquake fault, a crack which ran diagonal to the river, proved an ideal course for a side creek coming in from the north, and this side creek eroded a great gash of its own. There were other similar tributary canyons in the process of creation as century after century went around the clock. Rainfall was also helping to widen the main canyon, while in the bottom the surging river, carrying its cutting implements of sand, silt, and rocks of all sizes, went on wearing its bed deeper and deeper into the earth. The stream in the side canyon raced on to keep pace with the river. It cut equally well and it meets the river today deep in the canyon bottom. It is called Bright Angel Creek. After about six million years of this relentless and unceasing cutting and grinding and boring and drilling, the canyon was half a mile deep and five or more miles across. It was worthy of the name Grand Canyon even then. But the incessant water, sand, wind, and rain erosion had a long way yet to go. The whole Permian period had been exposed. And the river cut on into the Carboniferous limestone, the Redwall. It sheered the Redwall like a knife. It reached the Devonian period-the age of fishes

In the Darwinian scale-and it sliced through this in a short time, that is, geologically speaking. The Silurian period was missing and so was the Ordovician. An earlier erosion, millions of years ago, had removed those two strata. The river never missed them; it cut on into the Cambrian rocks which had once been laid down by the erstwhile Tonto Sea. Here it was exposing to daylight rocks that had been overlaid for five hundred million years. The skeletons of the ancient trilobites with their crablike bodies were exposed along with other marine life of a mysterious ancient world. And even deeper went the river to the very foundation of the Cambrian rocks and the meeting of the third geological era with the second. Here it turned back the pages of history to the Proterozoic, or more than a billion years. And finally it cut down to the oldest rocks on earth, rocks that comprised the first crust when the globe was forming a solid surface and the sun had not yet penetrated the mists, rocks that held not the first live thing, but rocks that antedated even life itself. Here, then, at the canyon bottom is the stuff the earth was made of two billion years ago.

It is quite a show.

From the Permian period back to the birth of the globe is what the river and the canyon have to exhibit to anybody who makes the trip from rim to river. Nowhere else on earth can you see such a performance.

And that is not all. The whole pageant is here, not just part of it. For, to the north in Utah, an easy day's drive, is Zion National Park. If you have seen the play called "From Archeozoic to Permian," which the Grand Canyon stages, there is a sequel called the "Fourth Era," which the Painted Desert (which you pass on the way to Utah) and Zion have to present. Here you will be able to see the history of the earth from the Permian period at the Grand Canyon rim through the whole fourth era, the Mesozoic. And there is one more act after that; it is found at Bryce Canyon, also in Utah, not far from Zion. Bryce will show you the last scene, the fifth-era formations, the Cenozoic, and that brings you right up to date. Thus it is possible for a visitor to start the day at Phantom Ranch in the canyon bottom, ascend the Bright Angel Trail to the south rim; drive via the Taken with a Linhof Camera-6 inch Schneider Xenar lens on 4x5 Ektachrome daylight film. The exposure was second at f.25. The time was a May morning with shrubs in their delicate spring finery. Dropping below the South Rim on the Kaibab Trail, O'Neal Butte stands out as an impressive pinnacle to cheer the hiker on his exciting adventure into the mighty Grand Canyon.

NOTES FOR PHOTOGRAPHERS OPPOSITE PAGE "SPRING WREATH-GRAND CANYON" BY JOSEF MUENCH. "CLOUDS AND SHADOWS-GRAND CANYON" BY GENE HELLAND.

4x5 Speed Graphic, 1/25th second at f.22, C filter, 127 mm. Ektar lens on Anscochrome. This view was taken from the North Rim of Grand Canyon. It was one of those days when the Canyon was at its colorful best. A cloud pattern in the sky and a cloud shadows in the Canyon emphasized and made more brilliant the Canyon colors. This is now the first viewpoint on the new road arriving at the Canyon from the south. It gives the visitor a real view of the Canyon at arrival instead of Grand Canyon village as in the past. July 1956, Deardorff camera, 8%-inch commercial Ektar, 1/25 second at f.20. Light reading at the Canyon is quite high in mid-summer, particularly when large clouds are in the air.

"AT LOOKOUT POINT-GRAND CANYON" BY RAY MANLEY. "THE ENCHANTED GORGE-GRAND CANYON" BY RAY MANLEY.

This picture was made from a point near Desert View (Indian watchtower) looking north to where the little Colorado joins the Colorado. 5x7 Deardorff, Anscochrome, 8% Ektar, f.32, 1/5th second, polaroid filter, July, 1956.

"EVENING GLOW-GRAND CANYON" BY GEORGE O. BONAWIT.

4x5 Speed Graphic Camera, Zeiss Tessar 135 mm. lens, one second at f. 16, on Kodachrome. Visitors to the Grand Canyon, who return time and time again, always remark about the ever-changing colors. This is because the colors change with the time of day, month and season. Taken from South Rim, Normal light in midmorning, October, the exposure was on Ektachrome, 1/10th second at f.16. Camera was 4x5 View, lens 5" Ektar. The view is roughly north from near the road to Cape Royal at the North Rim.

"VISTA ENCANTADORA-FROM NORTH RIM" BY HUBERT A. LOWMAN. "RAINBOW-POINT SUBLIME, NORTH RIM" BY HUBERT A. LOWMAN.

The photographer says: "Great puffy white clouds dotted the sky as I drove along the wilderness road toward Pt. Sublime on the North Rim. Then the sun was hidden and I moved into a shower. I could see that the disturbance was only local, so I went on out to the Point and waited. In about a half hour the sun suddenly broke through and a rainbow plunged into the Canyon, so I quickly moved into action even though light rain was still falling. By making sure no moisture touched the lens I kept the rain from interfering with picture taking. The late afternoon light was rather weak, the exposure being 1/5th second at f.rt on Ektachrome film. The lens was a 5" Ektar in 4x5 View camera."

CENTER PANEL "STORM'S ENDING" BY CHUCK ABBOTT.

The canyon and the river

From Painted Desert to Zion National Park, and, if he hurries, pull into Bryce Canyon National Park before dark. He will have run the gamut of geological history; he will have passed through every phase of the earth's development; he will have seen the home of every species of life since the first algae swam in the primordial sea; and he will have done it all in the space of one day.

As you stand beside the roaring river at the mouth of Bright Ángel Creek you wonder how much farther down into the earth this canyon will go. Where will it be in another million years? The answer is that the river will continue to cut deeper until its pitch toward sea level is sufficiently lowered so that it will no longer be a rushing torrent. At the bottom of Grand Canyon you are still more than two thousand feet above sea level. Thus the river has another two thousand feet of Archean rock to excavate before the force of gravity will be tempered and it will then be a quiet well-behaved river like the Hudson or the Delaware. Does the Archean rock extend down another two thousand feet? Yes, indeed-it extends down another thirty or forty miles, so the river will stop cutting long before it reaches the hot interior of the earth where the sun-stuff of three billion years ago is still molten.

And how long will it take to cut these next two thousand feet? Nobody knows. Since man has applied his knowledge to the phenomena at the Grand Canyon, a matter of less than a hundred years, there has been no perceptible change. Man's life span is too short to permit him to see the erosion taking place. He knows it is going on, but the movement, like that of the hour hand of his watch, is too slow for his eye to perceive.

It has been a little over four hundred years since white men first saw the Grand Canyon. And in accordance with geological time which reckons years by the hundreds of millions, man's total time on earth, so say nothing of a mere four hundred years, is not enough to count. Hence to man, change in the physiography of the Grand Canyon is negligible or nonexistent. The canyon looked very much as it does today when Columbus sailed from Spain, when Rome was founded, when Troy fell, when Hammurabi wrote the laws of Babylon. And it will still be the same two thousand years in the future. Man needn't be concerned.