Geological Survey Bulletin 613 Guidebook of the Western United States: Part C. The Santa Fe Route

A coal mine, plainly visible a quarter of a mile north of the track a mile west of Gallup, is one of the large producers of the area. Just south of a point two-tenths of a mile beyond milepost 163, west of West Yard siding (see sheet 16, p. 108), is a knob due to a mass of dark igneous rock (vogesite), cutting the coal-bearing rocks, and another small dike of the same material appears half a mile farther southwest.

SHEET No. 16 (click on image for an enlargement in a new window)

At milepost 163 sandstones below the coal measures appear, and a short distance north of milepost 166, which is at Defiance siding, they arch over, forming a well-marked anticline. Beyond this arch the beds dip west for a short distance at moderately steep angles, into a shallow syncline, out of which they rise again on an easterly dip at milepost 167. The easterly dip continues for some distance, bringing up lower and lower beds of the sandstone in succession toward the west. Finally at milepost 176 appears one of the lower sandstones, 200 feet thick, forming a high wall on both sides of the Rio Puerco valley, which in consequence becomes a canyon. These cliffs continue for several miles to the west.

At Manuelito (mahn-way-lee'to) considerable trading is done with the Navajo Indians who live on the reservation a short distance north. This place was named for a Navajo who was elected chief in 1855, when a treaty was arranged with the Navajos to end their depredations. This treaty, however, was not ratified by Congress, and lawlessness continued till the final subjugation of the tribe eight years later. Subsequently Manuelito was made head of the native police force and proved loyal to the Government.

Two-tenths of a mile beyond milepost 179 the State line is crossed and Arizona is entered. The State line is on the thirty-second meridian west of Washington (about 3 miles west of longitude 109° west of Greenwich) and was so defined by law at a time when the Government was attempting to establish an initial meridian passing through the old Naval Observatory at the National Capital. At this place the canyon walls show very massive gray sandstone with numerous shallow caves, alcoves, and buttresses, capped by dark-gray sandstones (probably Dakota).

The area of Arizona is 112,956 square miles. It comprises wide plateaus, in large part from 5,000 to 8,000 feet in height, numerous ridges and mountains, and many wide desert valleys. On account of its great variation in altitudes and its great width from north to south, the State presents a wide diversity of climate, from that of the hot regions near Fort Yuma to that of the cold forested mountains and high plateaus.

Arizona leads in copper production in the United States, the output in 1913 being valued at $63,228,127, or about 90 per cent of the total mineral production of the State. Gold was produced to the value of $4,023,911, and silver, which is mostly a by-product obtained in reducing copper ore, amounted to $2,384,647

Although the agricultural possibilities of the State are not developed to their full extent, the cultivated hay crop approached a value of $4,000,000 in 1914 and wheat $1,085,000. Wool yielded about $939,000. Range cattle growing is a large industry. Fruit of citrus and deciduous trees, cotton, and corn are being more and more cultivated as new lands are brought under irrigation.

The word Arizona is taken from the Papago language, in which it is said to signify place of small springs. With a population of 204,354, according to the census of 1910, or 1.8 persons to the square mile, it is one of the more thinly populated, of our Western States, though less so than Wyoming and Nevada. The ratio of males to females is 138.2 to 100. Of its 72,000,000 acres only 5,000,000 are privately owned, the remainder being public land, Indian reservations, or national forests. Originally Arizona was part of New Mexico, and it continued as such under United States dominion until 1863, when it was made a separate Territory and formally organized at Navajo Springs. Later the capital was at Fort Whipple, Prescott, Tucson, again at Prescott, and finally at Phoenix.

The settlement of Arizona has progressed slowly, and up to 1886 the murderous disposition of the Apache Indians greatly retarded its development. Mainly for this reason there were no white inhabitants in the large area north of Gila River prior to the treaty of 1848. From 1853 to 1857 several governmental surveys were made across the region, mainly to find routes for railways. Most of the earliest visitors were prospectors, and from 1847 to 1860 many mines were opened under more or less protection by the Government. The withdrawal of troops for the Civil War gave the Apaches opportunity to resume depredations, and about 1,000 settlers were killed. Most of the miming operations were discontinued, and the few white people who remained fortified themselves in Tucson, which was taken by the Confederates and held until Union troops came from California. After the war also there was much bloodshed by Indians, who killed about 400 settlers. Gen. Crook subdued the Apaches in 1873 and concentrated them in a reservation, but there were many serious outbursts later under Victorio and Geronimo, with numerous massacres. Victorio was killed in an engagement in 1863, but it was not until 1886 that Gen. Miles forced Geronimo to surrender, and then the Apaches were removed to other States. The Indians were difficult to fight, for they avoided open engagements and could travel fast and far on their ponies.

The Southern Pacific Railroad was built through Arizona in 1880, and the Atlantic & Pacific (now a part of the Santa Fe system) in 1883.

The history of the aborigines in Arizona is extensive, for on plains, on mesas, and in the cliffs there are many ruins of places occupied by the early people. Some of these ruins must be very old. However, it is believed that the number of people living in the region at any time may not have been great, for the aborigines frequently moved from place to place. The early expeditions of the Spanish explorers found many pueblos. The first Spaniard to enter Arizona was Marcos de Niza, a Franciscan friar who crossed its southwest corner in 1539. A year later Niza led Coronado to the Pueblo country, and two small expeditions from this great exploring party visited the Hopi country. The present Indian population of the State is nearly 42,000.

About a mile west of Lupton the Zuni and Wingate sandstones, which passed underground 3 miles east of Gallup, rise rapidly in succession, especially to the north of the railway, where the dips are steep for some distance. (See Pl. XIX, B, p. 103.) South of Lupton and extending to a point south of milepost 181 there are high cliffs of white to pink sandstones (the Zuni and Wingate) showing many remarkable pinnacles, buttresses, caves, and other features characteristic of erosion in soft, massive rock. They have been eroded by the rain, and especially by wind-blown sand, which cuts rapidly into rocks of this character. One of the most notable arches in these rocks is shown in Plate XX, B. It is some distance north of the railway. Beyond the cliffs west of Lupton the rise of the beds to the west brings up the thick succession of shales which lie beneath this sandstone. West of milepost 182 the dips are very low, so that the same rocks continue on both sides of the railway for a considerable distance. They are gray and purple shales with layers of gray sandstone, some of which are sufficiently thick and hard to form low mesas that rise at intervals far to the north and south.

PLATE XX.—A (top), BED OF RIO PUERCO AT NAVAJO SIDING, ARIZ. View southwestward. A typical arid-land arroyo, which is filled to the brim with a swiftly flowing torrent after a rain but soon becomes dry again. B (bottom), NATURAL BRIDGE IN MASSIVE SANDSTONE NEAR THE HAYSTACK ROCKS, NORTH OF MANUELITO, ARIZ. Shows the work of a small stream which enlarged a crack along a joint plane.

A short distance west of Houck siding the train enters a canyon about 2 miles long, the walls of which consist of the hard, coarse sandstone that underlies the shales exposed to the east. This rock is regarded as the eastward continuation of the Shinarump conglomerate, which is conspicuous in the country to the northwest. The dip to the west carries this sandstone below the surface west of the canyon, and rolling hills of red shales with gray sandstone layers continue westward to Winslow and beyond. These rocks are exposed here and there in shallow cuts along the railway and in the slopes of the adjoining hills and low mesas. They lie nearly flat.

A 303-foot well at Chambers affords a supply of water rising within 60 feet of the surface.

The first Territorial capital of Arizona was near Navajo, and there has been an Indian trading post there since 1863. Jacobs Well, an important water hole, is not far south. Near milepost 218 the train passes through a shallow canyon in red shale which is capped by a thin deposit of gray sandstone. These beds have a scarcely perceptible dip and constitute the surface along the slopes of the Rio Puerco valley past Pinta siding and Adamana, with remarkable uniformity over a wide area. The Rio Puerco in this region has a bed of considerable width and high banks, but most of the time it is dry or nearly so, as shown in Plate XX, A.

The "Petrified Forest," or series of petrified forests, lies a short distance south of Adamana, and the trip to it is made from that station. A small hotel provides accommodations for travelers. The distance to the farthest point usually visited is 9 miles, and this tour can be made in a day or less. In the region south of Adamana there are four "forests," the first 6 miles out, the second 8-1/2 miles, the third 13 miles, and the fourth, the "Rainbow Forest," about 2 miles northwest of the third. They are included in a Government reservation called "Petrified Forest National Monument," created by President Roosevelt in 1906 and placed in charge of the Secretary of Agriculture. The name "forest" is not appropriate, for the petrified tree trunks are all prostrate and are broken into sections. (See Pl. XXI.) The logs are the remains of trees that grew in Triassic time. The trees were of several kinds, most of them being related to the Norfolk Island pine (Araucaria excelsa), now used for indoor decoration. These gigantic fossil trees are of later date than those represented by the cones and twigs in the beds at Glorieta Pass, and, as might be expected, they resemble the living Araucarias more closely. They are probably the Triassic descendants of the Permian progenitors of the araucarian family. Doubtless they grew in a near-by region and, after falling, drifted down a watercourse and lodged in some eddy or a sand bank. Later they were buried by sand and clay, finally to a depth of several thousand feet. The conversion to stone was effected by gradual replacement of the woody material by silica in the form called chalcedony, deposited by underground water. A small amount of iron oxides deposited at the same time has given the beautiful brown, yellow, and red tints which appear in much of the material.

PLATE XXI.—PETRIFIED LOGS SOUTH OF ADAMANA, ARIZ. The logs were buried in the clays shown in the views.

All the "forests" present objects of interest, but a visit to the first and second illustrates most of the features. In places the logs are scattered over the surface in large numbers. They vary in size and in length of the trunk sections; in most places the sections are in no regular order, but some of them lie in line very nearly in their original positions. In the first forest they are all out of place, having either rolled down from their original positions in a sandstone layer at a higher level, or been left on the ground as the clay or sand that once inclosed them was washed away. In the second and third forests the original log-bearing stratum may be seen, with many logs only partly uncovered by erosion. Some of the tree trunks are 6 feet in diameter and more than 100 feet in length, but most of them are about half these dimensions. In the first forest there is a fine trunk that forms a natural bridge over a small ravine, the water having first washed away the overlying clay and sand and then, following a crevice, worked out the channel underneath. The length of this log is 110 feet, diameter 4 feet at butt and 1-1/2 feet at top. (See Pl. XXI, A.)

The petrified woods are beautiful objects for study. When thin slices are carefully ground down to a thickness of 0.003 inch or less and placed under the microscope they show perfectly the original wood structure, all the cells being distinct, though now they are replaced by chalcedony. By studying the sections, F. H. Knowlton has found that most of these araucarian trees were of the species Araucarixylon arizonicum, a tree now extinct. It is known to have lived at the same geologic time also in the east-central part of the United States, where the remains of some of its associates have also been found. These included other cone-bearing trees, tree ferns, cycads, and gigantic horsetails, which indicate that, at that time, the rainfall was abundant.

The entire area of the "forests" is included in the Government reservation, and visitors are prohibited from carrying away any of the petrified wood or damaging the logs in any way. Petrified wood occurs in many other places in these same beds to the north and south, notably in an area 6 miles north of Adamana or 5 miles north of Aztec siding, where there is an interesting "forest," known as the North Forest, of considerable extent. The logs are all in beds not far above the horizon of the Shinarump conglomerate.