BAUXITE AND ALUMINUM.

By W. C. PHALEN.

BAUXITE.

PRODUCTION.

The production of bauxite in the United States in 1908 amounted to 52,167 long tons, valued at $263,968, a decrease of 45,609 tons, or nearly 47 per cent in quantity, and of $216,362, or 45 per cent in value, as compared with the production of 1907. The average price of the material at the mines was about $5.06 per long ton, an advance of $0.15 over the price in 1907.

The list of States producing bauxite on a commercial scale remains as in 1907. These States are Alabama, Arkansas, Georgia, and Tennessee. As in past years, Arkansas leads in production with an output of considerably more than 60 per cent of the total. The actual production of this State, however, fell off about 43 per cent, and that of Georgia and Tennessee also decreased; the production of Alabama increased.

The following table gives the production and value of bauxite from 1889 to 1908, inclusive. In the collection of these statistics, the cordial cooperation of the state geologists of Georgia and Alabama in their respective States is hereby acknowledged.

Production of bauxite in the United States, 1889-1908, by States, in long tons.

CONSUMPTION.

The following table shows the annual production, imports, consumption, and value of bauxite in the United States during the last five years:

Production, imports, and consumption of bauxite in United States, 1904-1908, in long tons.

The following table shows the world's production of bauxite from 1905 to 1907, inclusive:

World's production of bauxite, 1905–1907, in long tons.

Few changes took place in the bauxite industry during 1908. The industrial depression which began in the fall of 1907 and extended into the year 1908 was felt in the bauxite and aluminum industry as well as in others. There was little or no new development or prospecting work done. Numerous new discoveries of bauxite, however, have been reported. An occurrence has been reported near Allentown, Pa., and another occurrence was visited by the writer about 7 miles northwest of Fort Payne, Dekalb County, Ala. The latter deposit is located a short distance from Big Will Creek, and the nearest station is Cordell, on the Alabama Great Southern Railroad. A few prospect pits have been sunk at this locality, an open cut has been dug, a shaft 50 feet deep has been made, and a few tons of ore have been thrown out. In the immediate vicinity numerous pockets of iron ore have been prospected, but, so far as known, no bauxite has ever been shipped from the locality.

Virginia. A deposit of bauxite ore in Virginia has been brought to the writer's attention by E. C. Harder, of the United States Geological Survey, who has supplied the following data regarding it:

The bauxite is found in Botetourt County, Va., about 2 miles east of Troutville, at the old Houston iron and manganese mines. The mines consist of two large open cuts about half a mile apart, and the bauxite occurs, though probably not in commercial quantity, in the westernmost of these. The cuts are in variegated clay at the foot of the Blue Ridge.

The rocks of eastern Botetourt County are of Cambrian age and have the following succession, beginning with the highest beds:

The lower Cambrian quartzite forms the western slope of the Blue Ridge. The Sherwood limestone and the "Buena Vista" shale form a gently sloping shelf at its foot, and the Natural Bridge limestone the valley to the west. Near the foot of the Blue Ridge the rocks are concealed by a considerable thickness of variegated clay and sand, most of which is residual, but part of which may be of fluviatile origin. The iron and manganese ores and the bauxite occur in these clays at or near the contact of the lower Cambrian quartzite with the overlying formation. The bauxite is associated with iron and manganese ores in bright-colored red, orange, brown, and pink clays lying on partly decomposed sandstone, horses of which extend upward into the clay. Most of the manganese ores occur as a replacement of the sandstone in these horses and in dark-colored clays immediately in contact with them. The iron ores, some of the manganese ores, and the bauxite occur in the variegated clays, the iron and manganese being in the form of irregular fragments and the bauxite in scattered masses. The clay forms a sort of blanket deposit over the decomposed sandstone and has an average thickness of from 15 to 30 feet, so that the ores associated with it are surface occurrences and do not extend to a great depth. The bauxite has a pisolitic texture and, as a rule, is highly ferruginous and dark red in color. Some of the ore, however, is light red or yellow. The pisolites vary in diameter from one-tenth inch to one inch, and consist of a thin shell composed of concentric layers; the interior is structureless, but usually porous and cellular.

New bauxite field in Georgia.-In the report for 1907 on the occurrence of bauxite, a note was given on a new field in Wilkinson County, Ga. Since that time, this new field has been studied in much greater detail by Otto Veatch, of the Geological Survey of Georgia, from whose article the following notes are in part abstracted and in part quoted.

The deposits are in no way connected with those of northwestern Georgia, either geographically or geologically, being located 150 miles distant and near the margin of the coastal plain. Macon is the nearest city, located 30 miles to the west. The bauxite apparently occurs near the contact between the Tuscaloosa (Lower Cretaceous) and Claiborne (Tertiary) formations which are chiefly made up of unconsolidated clays and sands, lying practically flat and having no pronounced structural features. The bauxite occurs in the form of beds either resting directly upon the Cretaceous clays or disseminated as nodules through them. Bauxite beds 10 feet thick have been observed.

The ore is generally either pisolitic or concretionary, but it is also amorphous, in which case it may be dense, halloysitic, or even flinty in appearance. Its color varies from almost white or cream to a bright red. It is generally hard, and no soft, granular, or claylike varieties have yet been discovered.

a Veatch, Otto, The bauxite deposits of Wilkinson County, Ga. Bull. Geol. Survey Georgia No. 18, 1909, pp. 430-447.

The following analyses, made by Edgar Everhart, chemist of the Geological Survey of Georgia, show the composition of the ore:

The origin of the bauxite is obscure. The geological conditions under which it formed were evidently different from those of the Georgia-Alabama and the Arkansas districts, and it is not believed that the theories advanced in explanation of those deposits are applicable to the Wilkinson County bauxite.

The close association of the Wilkinson County bauxite with the white clays and sedimentary kaolins of the Cretaceous at once suggest these clays as the source of the alumina of the bauxite. The facts collected in the field and the chemical analyses favor most strongly the theory that the bauxite has resulted from a chemical alteration in place of pure clays. The following analyses suggest a gradation from clay to bauxite:

All of the samples are from Wilkinson County. No. 1 is an unaltered white clay, and is representative of extensive beds which occur in Wilkinson and adjoining counties. Nos. 2 and 3 are semi-indurated clays, which contain coarse nodules and concretions and have the appearance of bauxite; Nos. 4 and 5 show a further decrease in silica, and No. 6 is a relatively pure bauxite. The silica in Nos. 4, 5, and 6 exists mainly in combination with alumina as clay and partly as soluble silica, but does not exist in appreciable percentages as free silica or quartz sand.

In the field samples of clay may be observed which in their physical appearance suggest an alteration process to bauxite. These clays are semihard, mealy, and have lost some of their plasticity; they contain both nodules without