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ANCIENT LANDSCAPES OF THE GRAND CANYON REGION
ANCIENT LANDSCAPES OF THE GRAND CANYON REGION
THE GEOLOGY OF GRAND CANYON, ZION, BRYCE, PETRIFIED FOREST & PAINTED DESERT BY Edwin D. McKee, Asst. Director Museum of Northern Arizona Sketches and Charts by Louis Schellbach 3rd Park Naturalist, Grand Canyon National Park, and Russell Hastings PUBLISHED BY EDWIN D. MCKEE 1931 COPYRIGHT 1931 Edwin D. McKee Thirteenth Edition, 1952 PRINTED BY COCONINO SUN CO. Flagstaff, Arizona...
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INTRODUCTION
INTRODUCTION
Probably no place in the world of similar area has recorded a more complete or a more interesting resume of the earth’s history than has the high plateau country of northern Arizona and southern Utah. Although many great events and some long intervals of time are not represented by the formations of this region, yet of the five major chapters or eras into which all of time has been divided by geologists, at least some parts of each have left their traces in this area. Whether on the brink of the
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THE EARTH’S OLDEST ROCKS (THE ARCHEAN ERA)
THE EARTH’S OLDEST ROCKS (THE ARCHEAN ERA)
Looking into the depths of Grand Canyon from any point within the Bright Angel section, one is immediately impressed by the narrow V-shaped gorge cut in the black rocks at the bottom. This is popularly termed the Granite or Inner Gorge. Within its walls one is in another world, both scenically and geologically. Their steep, bare sides, whose surfaces are chaotic in the extreme, have a history—long and complex. The rocks of which they are formed—some of the oldest known today on the surface of th
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GRANITE IN GRAND CANYON (THE ARCHEAN ERA)
GRANITE IN GRAND CANYON (THE ARCHEAN ERA)
Within the black, crystalline rocks of the Inner Gorge may be seen many large streaks, bands or irregular masses of a lighter color. From the Canyon rim these appear white, but from nearby they are usually pink. These light colored rocks are granites with a coarse crystalline texture. Granites derive their name from their granular texture. They are formed by the slow cooling of molten masses that have been forced into older rocks from the earth’s interior. From a similar source are formed lavas
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ALGONKIAN ROCKS IN GRAND CANYON
ALGONKIAN ROCKS IN GRAND CANYON
Along Bright Angel Canyon and in several other places in the Grand Canyon, rocks of Algonkian age, representing accumulations of sediments several thousand feet in thickness, are found. Below and to the north of Desert View (southeast of Cape Royal on the North Rim) they form the open floor of the Canyon. Everywhere the most conspicuous layer of this series is a mud rock of brilliant vermilion color. However, the rocks also include a conglomerate or pebble layer, a dark limestone formed principa
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FORMATION OF MOUNTAINS (THE ALGONKIAN ERA)
FORMATION OF MOUNTAINS (THE ALGONKIAN ERA)
The Algonkian rocks of the Grand Canyon region were bent and broken into mountains at an early date. In many places sloping layers showing the steep angle at which they were tilted are easily visible, even from the Canyon rim. Folded areas and strata which have been shattered are also conspicuous features here and there. The mountains which they formed, however, are now missing for they were worn away in large measure by slow erosion. Today only remnants—small hills on a general level surface—re
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EARLY CLIMATES (THE ALGONKIAN ERA)
EARLY CLIMATES (THE ALGONKIAN ERA)
The rocks of Algonkian age are roughly estimated to be at least six or seven hundred million years old, yet from all indications they were formed under conditions of climate not unlike those of far later periods of history. In several parts of the world traces of great ice sheets—glaciers which scratched and eroded the surface—are found preserved in Algonkian rocks. In other places, including the Grand Canyon, ancient flows of lava are found where they gushed out upon the surface of an old land
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OLDEST KNOWN LIFE (THE ALGONKIAN ERA)
OLDEST KNOWN LIFE (THE ALGONKIAN ERA)
The oldest forms of life represented in rocks of Grand Canyon are found in strata of the Second, or Algonkian, Era. Certain layers of limestone showing peculiar structural patterns on their surfaces are interpreted as being the reefs built up through the activities of primitive one-celled plants known as algae. Similar structures are being formed today by plants of this type. Near Harper’s Ferry, West Virginia, for example, algae are building up limestone layers almost identical to the fossil on
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FIRST ANIMAL LIFE—THE TONTO ROCKS (CAMBRIAN PERIOD)
FIRST ANIMAL LIFE—THE TONTO ROCKS (CAMBRIAN PERIOD)
Great highlands which were formed in the Grand Canyon region during the Second Era of history were afterwards gradually worn away by erosion until near the start of the next era a flat, almost featureless plain existed. Here and there, however, isolated hills of dark, crystalline rocks of the First Era stood above the general surface, as seen opposite Yaki point. In other places, such as to the west of where Bright Angel Creek now flows, small mountains of red Algonkian rocks (Second Era) remain
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THE MISSING PERIODS OF THE THIRD ERA (ORDOVICIAN AND SILURIAN PERIODS)
THE MISSING PERIODS OF THE THIRD ERA (ORDOVICIAN AND SILURIAN PERIODS)
The geologist has found that two long periods of history are lacking in the great succession of ages represented by the strata in the Grand Canyon walls. These missing periods which belong to the Third Era are known as the Ordovician, the time when fish first appeared in the seas, and the Silurian, the time when millipeds and scorpions became our first air breathers. These ages immediately followed the Cambrian and involved millions of years. The absence of the first of them is explained by some
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THE AGE OF FISH (DEVONIAN PERIOD)
THE AGE OF FISH (DEVONIAN PERIOD)
A FRESH WATER FISH OF DEVONIAN AGE During that period of geologic time commonly known as the “age of fish,” sands and limes were accumulated on the surface of the Grand Canyon region filling in old river channels and burying the bodies of fish and other animals. The deposits formed at this time were later eroded to a large extent. The surface of the land was worn and washed away until finally only isolated patches or pockets of limestone and sandstone remained. These we find today exposed in the
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SEA LIFE FROM THE NORTH—THE REDWALL LIMESTONE (MISSISSIPPIAN OR LOWER CARBONIFEROUS PERIOD)
SEA LIFE FROM THE NORTH—THE REDWALL LIMESTONE (MISSISSIPPIAN OR LOWER CARBONIFEROUS PERIOD)
REDWALL FOSSILS (NATURAL SIZE) One of the most prominent and conspicuous features of the Grand Canyon is the great red cliff of limestone about midway in its walls. This cliff is the highest in the Canyon—averaging about 550 feet in the area of Bright Angel Canyon. In most places it is almost vertical, and in some it even overhangs to such an extent that a visitor once aptly said, “The Washington Monument might be placed beneath it and kept out of the rain.” To the prospector this formation is k
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TRACKS IN THE SUPAI SANDSTONE (PERMIAN PERIOD)
TRACKS IN THE SUPAI SANDSTONE (PERMIAN PERIOD)
During that period in geological history known as the Permian, when some of the beds of soft coal in eastern America were being formed, a large area in northern Arizona was receiving red sediments from the east, probably carried by rivers from the granitic highlands of that region. Today these sediments appear in the Grand Canyon walls as alternating layers of red sandstone and shale immediately above the great Redwall. They are almost a thousand feet in thickness. TRACKS OF SHORT-LEGGED PREHIST
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LANDSCAPES OF THE HERMIT SHALE (PERMIAN PERIOD)
LANDSCAPES OF THE HERMIT SHALE (PERMIAN PERIOD)
LANDSCAPE AT TIME HERMIT SHALE WAS FORMING (RECONSTRUCTION. MUSEUM NORTHERN ARIZONA) FOSSIL FERN FROM THE HERMIT SHALE (REDUCED) Concerning the conditions under which the topmost red formation of the Grand Canyon (the Hermit Shale) was developed, and the nature of its origin, we have today a rather definite and interesting picture. A wealth of fossil plants and a number of tracks of animals have been found excellently preserved in its muddy layers, and by means of these and other indications the
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WIND-BLOWN SAND—THE COCONINO (PERMIAN PERIOD)
WIND-BLOWN SAND—THE COCONINO (PERMIAN PERIOD)
The light-colored formation which appears as a conspicuous ribbon-like band around the upper part of the Grand Canyon has long presented a puzzle concerning its origin. The grains of white sand of which it is composed apparently were deposited at steep angles, for the many and varied slopes which were formed may be readily seen today on the surface of the rock. These slopes were probably once the lee sides of sand dunes deposited by winds in an area bordering the sea. We find the only traces of
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WARM SEAS FROM THE WEST—THE TOROWEAP AND KAIBAB FORMATIONS (PERMIAN PERIOD)
WARM SEAS FROM THE WEST—THE TOROWEAP AND KAIBAB FORMATIONS (PERMIAN PERIOD)
SEASHELLS FROM KAIBAB LIMESTONE (REDUCED) Along both sides of Grand Canyon at the top, two buff and gray layers of limestone stand out as massive cliffs separated by a tree-covered slope. The upper of these limestones forms the plateau surface and may be seen for a great distance in every direction. Both layers were formed as the result of vast accumulations of organic and sandy materials on sea bottoms, and in places are composed largely of the remains of marine life—shells, corals and sponges.
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REMNANTS OF YOUNGER STRATA—RED BUTTE AND CEDAR MOUNTAIN (MOENKOPI FORMATION: TRIASSIC PERIOD)
REMNANTS OF YOUNGER STRATA—RED BUTTE AND CEDAR MOUNTAIN (MOENKOPI FORMATION: TRIASSIC PERIOD)
Two isolated hills of unusual interest rise above the plateau surface near Grand Canyon. Looking east from Desert View (Navajo) Point one of these, a flat-topped mesa called Cedar Mountain, may be seen. The other, known as Red Butte, is a rounded hill about fifteen miles to the south of Grand Canyon village. The most interesting feature of these hills is found in the fact that they are composed for the most part of red sandstones and shales which once formed a continuous layer over this entire p
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THE PETRIFIED FOREST (SHINARUMP AND CHINLE FORMATIONS; TRIASSIC PERIOD)
THE PETRIFIED FOREST (SHINARUMP AND CHINLE FORMATIONS; TRIASSIC PERIOD)
The Petrified Forests of northern Arizona and southern Utah were formed from trees which grew during a period known as the Triassic. The type of environment in the Painted Desert region during that period makes a very interesting speculation. The landscape of this ancient country, as interpreted from the present rock formations found there, was that of a low, flat area, perhaps a floodplain, where rivers and streams meandered back and forth, depositing first large pebbles and sand, and later a g
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DINOSAUR TRACKS (WINGATE-KAYENTA; JURASSIC PERIOD)
DINOSAUR TRACKS (WINGATE-KAYENTA; JURASSIC PERIOD)
Dinosaur means “terrible lizard.” Everyone has heard this name and attaches to it at least a vague conception of a creature of peculiar shape and tremendous size. In the dim far-away past these giant reptiles lived, developed and died in many parts of this country, but to most of us, they are only fantastic creatures in literature—not live or moving animals. DINOSAUR TRACKS. PAINTED DESERT The reality of the dinosaur should become apparent to those who travel through the Painted Desert region of
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THE ROCKS OF ZION CANYON AND RAINBOW NATURAL BRIDGE (NAVAJO SANDSTONE; JURASSIC PERIOD)
THE ROCKS OF ZION CANYON AND RAINBOW NATURAL BRIDGE (NAVAJO SANDSTONE; JURASSIC PERIOD)
The lure of a desert with its drifting sands, its scattered oases, and its broad extent has ever been great. Today in the Southwest, cut off from the moist ocean breezes of the west by the lofty Sierra Nevadas and further isolated by the Rocky Mountains to the east, is America’s great desert region. Here the winds and the rains are constantly at work tearing down and sculpturing the great land masses, while in places the wind is piling up the sand and debris to form dunes and new lands. Far back
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FROM SEASHELLS TO COAL BEDS (DAKOTA. MANCOS, MESA VERDE; CRETACEOUS PERIOD)
FROM SEASHELLS TO COAL BEDS (DAKOTA. MANCOS, MESA VERDE; CRETACEOUS PERIOD)
CRETACEOUS SHELLS FROM SOUTHERN UTAH During the last part of the “Age of Dinosaurs,” in that period of history known as the Cretaceous, much of northeastern Arizona, southern Utah, and northwestern New Mexico apparently was submerged beneath a sea. Mollusks abounded, and various other types of water animals swam or crawled in this region. Their shells were buried and preserved among the muds and limes which were accumulating, and today many of them are found in the rocks of this age. As time wen
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BRYCE CANYON FORMATION (WASATCH: EOCENE EPOCH)
BRYCE CANYON FORMATION (WASATCH: EOCENE EPOCH)
The formation found at Bryce Canyon and at Cedar Breaks in southern Utah has the distinction of being composed of the most recently formed sedimentary rocks in this plateau region. It was during the early part of the last great chapter of history that lime and some sand were accumulating here in fresh water. They are believed by most geologists to represent the deposits of ancient lakes and in them are found freshwater mollusks. Rivers and other agents of deposition probably also took a part in
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A GREAT EROSION SURFACE (CENOZOIC AGE)
A GREAT EROSION SURFACE (CENOZOIC AGE)
The level, flat and almost featureless skyline of Grand Canyon is an outstanding characteristic of the plateau of northern Arizona. This surface is fascinating to some; monotonous to others. To all, it is one of the most striking features of the region. The history which it represents, moreover, is of extreme interest and impressive length. Here on the top of the great plateau is seen the result of vast erosion. Long periods of work by water, wind, and other elements have gradually worn away str
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CRUSTAL MOVEMENT AT GRAND CANYON (CENOZOIC AGE)
CRUSTAL MOVEMENT AT GRAND CANYON (CENOZOIC AGE)
Many visitors to the Grand Canyon are distinctly surprised when they find numerous seashells, corals, and sponges, beautifully preserved in the limestone layer upon which they are standing. The idea immediately occurs that this region was once beneath the sea. Obviously then either the land has risen or the ocean has receded. A careful study of the region shows that the rock strata which form the great plateau of northern Arizona have been bent into a huge arch or dome. The Santa Fe railway trav
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CUTTING THE GRAND CANYON (PLIOCENE AND PLEISTOCENE EPOCHS)
CUTTING THE GRAND CANYON (PLIOCENE AND PLEISTOCENE EPOCHS)
“WHAT FORCE HAS FORMED THIS MASTERPIECE OF AWE? WHAT HANDS HAVE WROUGHT THESE WONDERS IN THE WASTE? O RIVER, GLEAMING IN THE NARROW RIFT OF GLOOM THAT CLEAVES THE VALLEY’S NETHER DEEP, FIERCE COLORADO, PRISONED BY THY TOIL, AND BLINDLY TOILING STILL TO REACH THE SEA. THY WATERS, GATHERED FROM THE SNOWS AND SPRINGS AMID THE UTAH HILLS, HAVE CARVED THIS ROAD OF GLORY TO THE CALIFORNIA GULF.” —HENRY VAN DYKE Very difficult is it for the average human fully to realize, to comprehend the tremendous p
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THE FORMING OF ZION CANYON (PLIOCENE AND PLEISTOCENE EPOCHS)
THE FORMING OF ZION CANYON (PLIOCENE AND PLEISTOCENE EPOCHS)
“A Yosemite Valley in colors” is a very apt description which has often been applied to Zion Canyon in southern Utah. Sheer-walled with a beautiful flat valley floor, this canyon is not unlike California’s glacier-carved fairyland in general size and shape, but in formation it has a very different history. ZION CANYON The brilliant Vermilion Cliffs which form the bottom two thousand feet of Zion’s walls and the contrasting White Cliffs which rise an additional thousand feet are hard, resistant s
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GLACIERS (PLEISTOCENE EPOCH)
GLACIERS (PLEISTOCENE EPOCH)
“What part did glaciers play in cutting the Grand Canyon?” This is a question asked almost daily on the rim of that great chasm. Everyone has heard of the mighty ice sheets which somewhere back in geologic history covered a large part of eastern and midwestern United States. Many people have seen beautiful Yosemite Valley in the far west, and have been told how it was carved by the action of glaciers. It is not altogether strange, therefore, that visitors to the Grand Canyon should associate the
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SAN FRANCISCO MOUNTAIN VOLCANIC FIELD (PLIOCENE AND PLEISTOCENE EPOCHS)
SAN FRANCISCO MOUNTAIN VOLCANIC FIELD (PLIOCENE AND PLEISTOCENE EPOCHS)
VIEW OF VOLCANOES FROM NORTH Over a large part of the great plateau of northern Arizona are found sheets of hard lava and cone-shaped craters. The center of this volcanic activity is located in the San Francisco Peaks just north of the town of Flagstaff, but lavas and cones are found westward beyond Williams and to a considerable extent in every other direction. Looking south from Grand Canyon these peaks may be seen to rise high above the plateau and are a very beautiful sight. From Flagstaff a
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ELEPHANTS AND CAMELS (PLEISTOCENE EPOCH)
ELEPHANTS AND CAMELS (PLEISTOCENE EPOCH)
It was during the fifth and last great era in the earth’s history that mammals developed and that man made his appearance on earth. In many places in the world the remains of animals that lived during various parts of this age have been preserved. In the famous asphalt pits of California literally hundreds of the bones of large mammals—tigers, mastodons, wolves and many others—have been brought to light. In the receding ice of northern Siberia, large mammoths—elephant-like animals representative
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ADVENT OF MAN IN THE SOUTHWEST (PLEISTOCENE HISTORIC)
ADVENT OF MAN IN THE SOUTHWEST (PLEISTOCENE HISTORIC)
After reviewing the chapters of the earth’s history and witnessing the procession and the slow but steady development of life through the ages, it is very natural that one should wonder when man came upon the scene. Compared with the hundreds of millions of years which have elapsed since the time of the first plants, or the millions of years following the first appearance of vertebrate animals, the age of man is as nothing. In the Old World there is evidence that humans existed before the last g
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GEOLOGICAL BIBLIOGRAPHY OF GRAND CANYON REGION Including Zion, Bryce, Painted Desert, and Petrified Forest
GEOLOGICAL BIBLIOGRAPHY OF GRAND CANYON REGION Including Zion, Bryce, Painted Desert, and Petrified Forest
Allen, V. T., Triassic Bentonite of the Painted Desert: Am. Jour. Sci., vol. xix, April, 1930. Baker, A. A. and others, Notes on the Stratigraphy of the Moab Region, Utah; Bull. Am. Assoc. Petrol. Geol., vol. 11, 1927. —— and Reeside, J. B., Correlation of the Permian of southern Utah, northern Arizona, northwestern New Mexico, and southwestern Colorado: Bull. Am. Assoc. Petrol. Geol., vol. 13, no. 11, Nov., 1929. ——, Dane, C. H., and Reeside, J. B. Jr., Correlation of the Jurassic Formations of
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