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The Geological Exploration of Arizona: The Role of State and Federal Surveys and the Geologic Map of Arizona

Article Author(s): 

Steve Reynolds
Jon Spencer
Stephen Richard
Phil Pearthree

The Great Western Expeditions and Surveys (1853-1879)

The origins of the Geologic Map of Arizona can be traced to the great expeditions and surveys that explored the southwestern United States between 1853 and 1879. The illustrious journeys of John Wesley Powell down the uncharted Colorado River in 1869 and 1871 are perhaps the most familiar to Arizonans. However, geologists accompanied other expeditions, including those headed by Lt. Amiel W. Whipple, Lt. Joseph C. Ives, and Capt. George M. Wheeler. In fact, some of the most famous geologists of the 19th century were involved in the early geological exploration of Arizona and surrounding regions, including Jules Marcou, J. S. Newberry, G. K. Gilbert, C. E. Dutton, and, of course, John Wesley Powell. They had to explore unfamiliar terrain and surmount tremendous difficulties while "geologizing" the countryside. In spite of the imposing obstacles and the limited time available, these geologists made many keen observations and conclusions that remain valid to this day. Some of the most fundamental concepts of geology were first developed during those early surveys.

One of the first geologists to enter Arizona was Jules Marcou. He accompanied the 1853 Whipple expedition as it crossed northern Arizona, exploring for a railroad route along the 35th parallel. Marcou's observations were severely hampered by a series of winter storms that concealed the rocks beneath a shroud of snow. Nevertheless, he described vast areas containing petrified wood near the present-day location of Petrified Forest National Park and noted that the San Francisco Mountains were extinct volcanoes.

The second geologist to visit the San Francisco Mountains was J.S. Newberry of the 1857-58 Ives Expedition. This expedition departed from Fort Yuma and sailed up the lower Colorado River in a steamship. It then traveled overland toward the San Francisco Mountains and on to Fort Defiance in the northeastern part of the state. Newberry was exuberant upon reaching the forested Colorado Plateau, after traversing the "volcanic and desert region of the lower Colorado" (Newberry, 1861). He states (p, 59):

We had all been wearied by the monotonous prevalence of the products of a single destructive force [volcanism]; and the varied and beautiful volcanic minerals so profusely scattered over the Colorado basin, devoid of all traces of organisms, and associated with the death-like sterility now pervading all that area, had ceased to excite a pleasurable scientific interest, and had even produced a positive thirst for life!; a longing to reach some region where nature's vital fires had not burned out; where the varied forms of recent animal and vegetable life adorned the earth's surface, and the rocks below contained in their fossils a record of its prevalence on sea and shore from the earliest ages.

This same lack of fossils in much of western Arizona continues to frustrate geologists to this day.

Newberry's observations regarding the San Francisco Mountains are in accord with those of modern geologists, In reference to some of the most recent volcanic features, he states: “... showing by all their surroundings that they have been in action, as it were but yesterday, and might be again tomorrow." This is undoubtedly one of the first statements published concerning potential volcanic hazards of Arizona. Newberry also characterizes some of the more recent lava flows as being "as little affected by the action of the elements as slag fresh drawn from a furnace." He likened the appearance of the San Francisco Peaks above the surrounding plateau to "some rocky island rising from the surface of the sea," and indicated that the main peak is "volcanic throughout, and is, in fact, a huge volcano whose fires have been but recently extinguished." The San Francisco volcanic field indeed contains one of the most recently active volcanic areas in Arizona. Newberry's writings also reveal his surprise upon encountering the deceptively hidden gorge of the Little Colorado River. While traveling upon what he thought was a "smooth and grass-covered plain," he suddenly found himself on the brink of "a series of canons ... forming a labyrinth of difficulties effectually arresting our progress in the line we had hoped to follow." (p. 61). In honor of Newberry's pioneering spirit, and that of his commander, Lt. J. C. Ives, many physiographic features of Arizona and California bear their names (Granger, 1960).

In 1853, a few years before the Ives expedition, the U.S. government negotiated the Gadsden Purchase from Mexico and dispatched surveys to explore the newly acquired land. Only a minor amount of geologic work was done in conjunction with these surveys. However, C. C. Parry, a scientist on the Emory Survey, made the following key observation: "... copper is quite frequently found in connexion [sic] with porphyritic rocks," (Parry, 1857, p, 21). This observation is an uncanny anticipation of our modern-day understanding that nearly all of Arizona's large copper deposits are directly associated with porphyritic rocks (i.e., a type of granitic rock that contains both large and small crystals). In fact, the association is so strong that the deposits are commonly called porphyry copper deposits. It is important to remember that the first large copper mines at Ajo and Bisbee had not yet been developed when Parry made his incisive observation.

The next important geologist to arrive on the Arizona scene was John Wesley Powell. Powell is probably best known for his pioneering exploration of the Colorado River and Grand Canyon. However, he remained an influential figure in Arizona geology long after his initial trips down the Colorado River in 1869 and 1871. He was in charge of a government-sponsored survey that continued to explore northern Arizona until around 1879. Powell was instrumental in the creation of the U.S. Geological Survey (U.S.G.S.) and served as its second director (Bartlett, 1962). Powell's initial journey down the uncharted Colorado River in 1869 is a hallmark of adventure, courage, and persistence. Powell and his companions never knew what dangers lay before them, what evil tidings were borne by the distant rumble of rapids, or whether their provisions and patience would hold out for an unknown number of days. In his fascinating book, Canyons of the Colorado, Powell (1895) writes (p. 247):

The flour has been resifted through the mosquito-net sieve; the spoiled bacon has been dried and the worst of it boiled; the few pounds of dried apples have been spread in the sun and reshrunken to their normal bulk. The sugar has all melted and gone on its way down the river. But we have a large sack of coffee ....

We are three quarters of a mile in the depths of the earth, and the great river shrinks into insignificance as it dashes its angry waves against the walls and cliffs that rise to the world above; the waves are but ripples, and we but pigmies, running up and down the sands or lost among the boulders.

We have an unknown distance yet to run, an unknown river to explore. What falls are there, we know not; what rocks beset the channel, we know not; what walls rise over the river, we know not. Ah, well! We may conjecture many things. The men talk as cheerfully as ever; jests are bandied about freely this morning; but to me the cheer is somber and the jests are ghastly,

In spite of such unavoidable apprehensions, Powell was always carefully observing the geology of the canyon. His thoughts were generally occupied by the large-scale features and problems, rather than by the specific characteristics of a single rock type – his vision and imagination were uncluttered by detail. While pondering some fairly recent lava flows that had spilled over the sides of the canyon, Powell envisioned the following: "What a conflict of water and fire there must have been here! Just imagine a river of molten rock running down into a river of melted snow. What a seething and boiling of the waters; what clouds of steam rolled into the heavens!"

A number of features in the canyon were originally named by Powell and his men. These include Bright Angel Creek, Marble Canyon, and Lava Falls.

After his two river excursions, Powell organized a survey to explore the Colorado Plateau around the Grand Canyon. The Powell Surveys included two famous geologists, Clarence E. Dutton and G. K. Gilbert. Dutton's 1882 treatise on the Grand Canyon is replete with eloquent, flowing prose and exquisite illustrations. A few of Dutton's vivid passages are quoted below.

In reference to cliffs formed of Jurassic Navajo Sandstone, Dutton wrote (p. 36):

It might be imagined that such fronts would be monotonous and tame, and once seen would soon lose all interest. Let us not underrate the versatility and resources of Nature, nor question her good taste, for she has made these walls as full of life, variety, and expression as any others, and yet has conserved the noble dignity of which simplicity is an essential part ... [the sandstones] often weather into domes and half-domes of bald, white rock which look a calm defiance of human intrusion. Occasionally, the austerity of these forms is exchanged for those of the opposite extreme, as if nature were tired and impatient of all this solemn dignity, and the proverbial step from the sublime to the ridiculous is actually taken ... we shall perceive numberless rock-forms of nameless shapes, but often grotesque and ludicrous, starting up from the earth as isolated freaks of carving or standing in clusters and rows along the white walls of sandstone. They bear little likeness to anything we can think of, and yet tease the imagination to find some- thing whereunto they may be likened. Yet the forms are in a certain sense very definite, and many of them look merry and farcical. It is a singular display of Nature's art mingled with nonsense.

Upon examining the extinct volcanoes along the north rim of the Grand Canyon, Dutton comments (p. 83): "We wonder what their age may be; what time has elapsed since they vomited fire and steam." In reference to Point Sublime on the north rim (which Dutton first named), he writes (p. 142): "Great innovations, whether in art or literature, in science or in nature, seldom take the world by storm. They must be understood before they can be estimated, and must be cultivated before they can be understood." Dutton's 1882 monograph is heartily recommended to anyone who is interested in 130-year old descriptions and illustrations of the Grand Canyon.

A contemporary of the Powell Survey was the U.S. Army's Wheeler Survey, which explored parts of northern and eastern Arizona. At one time or another, the survey was accompanied by several geologists, including G. K. Gilbert. Like other surveys, the Wheeler expedition had its share of difficulties. Around Canyon De Chelly, the Wheeler Survey encountered rain storms, fields of mud, rattlesnakes, and poisonous, five-inch-long centipedes that had a tendency to take refuge in their bed clothes (Bartlett, 1962, p. 360). In addition, several of Wheeler's men were killed in an ambush by Mohave Indians. Nevertheless, the science and exploration went on.

In 1879, the various surveys were consolidated into the U.S. Geological Survey. The Powell and Wheeler Surveys were discontinued, bringing to a close the first phase of geological exploration in Arizona.

Senior Geologist
Arizona Geological Survey


Research Geologist
Arizona Geological Survey

Steve Reynolds

Arizona State University School of Earth and Space Exploration

Steve Richard

Research Geologist
Arizona Geological Survey

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