Daily Arizona silver belt., 1907-01-06
IS THIRD IN
 COPPER OUTPUT
Comprehensive Story of Arizona s Lead ing Industry by Horace J. Stevens First Mining in Globe District and the First Big Mine.

son to believe that che output will con tinue to increase for many years to come.
 Arizona has nearly quarter of the copper mines of the United States.
 Many of them are of very doubtful value, few are of fully demonstrated worth, and a considerable number give promise of becoming both large and profitable producers The mere fact that a copper mine is located in Arizona should not prejudice opinion for or against it. Some of the best and some of the worst mines ever opened are in this territory, and each mine should be judged individually on its merits.
 There are evidences of rude mining by prehistoric people at a number of points in the territory hut no traces of smelling, and had the copper ores been reduced to slag, and possibly rem nants 1.-the furnaces, could hardly have escaped attention in modern days. It seems likely that iron ochres, malachite and azurite were mixed in crude way for pigments. Prehistoric turquoise mines have been found at several points, notably in the Dragoon noun tain range.
 The first copper made in Arizona was turned out of an adobe furnace at the Longfellow mine. Clifton, in 1873. The nearest railroad point WAS 500 miles distant at that time. The development of the mineral resources of Arizona has been a remarkable one during the three decades that have since elapsed.
 The copper zone of Arizona, broadly speaking, has general southweSterly and northeasterly trend, and the cop per deposits, as a rule, are found along the contacts of igneous rocks, such as porphyry and diorite, with limestone of the Palezoie group, mostly of the ear boniferous series. The general geolog ical conditions of Arizona are much the same as in the adjoining Mexican state of Sonora.
 Copper ores are found in more or less profusion in every county of the territory. And the counties are of a prineely size, and as the topography ranges fro mhilly to mountainous in most parts, not even the best known dis triets have been developed yet, or even prospeeted. Nearly all of the ores of copper are found in Arizona and native copper is not of uncommon occurrence, especially in the mines of Clifton and Bisbee. The principal copper districts are four in number, as follows: Bis bee, in Cochise county, only six miles from the Mexican border; Jerome, Ya vapai county, in the northwestern part of the territory; Clifton, including Mo renci, in Graham county, north of Bis bee, and close to the New Mexican border; Globe, Gila county, not far from the center of the territory. In addition to these four principal dis tricts, all of which are considerable producers, in about the order given, there are a dozen or more smaller dis. tricts, such as the Helvetia, in Pima county, the Wiekenberg and others.
 The Bisbee district, of which the town of that name is the center. is really part, geographically, of the great Sonora copper belt of Mexico The ore depos its occur in carboniferOus limestone, bedded in nearly horizontal planes, and underlaid by quartzite. The veins are notable for the quantity of fuecan along the walls, and are easily mined as a rule. The clay carries consider able finely eOmminute native copper and masses of native metal of respectable size are occasionally encountered The oxidized zone extends to a depth of per haps 400 feet and is succeeded by m altered iron-eopper sulphides that aver age excellent values. The oxidized zone is notable for the richness and ex tent of its high grade carbonate ores.
 The country rock of the Jerome dis trict is slate, extensively intruded by diOrite igneous rocks, slates and dior ties, having a capping of uneomfort able limestones of later age and devoid of copper. There is limited zone of oxidized ores, but the principal depend enee is placed upon the unaltered dis scminated sulphides. These are by no means remarkable for their high per centages of copper, but are notable for their great extent and the high values carried in gold and silver.
 The Clifton district has quartzite and limestone superimposed on granite, with intrusive igneoua rocks of both gasic and acid type, the entire formation be ing greatly faulted. Ore occurs in both the eruptive rocks and the limestone. It was in this district that the first Arizona copper mining was done there decades ago. There were very extensive deposits of rich oxidized ores near the surface, along the contacts between the porphyry and magnetism limestone. Those ores were self-mixing and highly profitable, but gave out at shallow depth and, contrary to the usual rule. were not succeeded by sulphides. Elk tensiye openings in the porphyry of Humboldt mountain have developed enormous beds of low grade sulphides during the past ten years, and these are the mainSay of the district, all | though some carbonates are still mined. l
 The teaching process, little used in the United States, is employed to ad- | vantage in the treatment of certain of the lowgrade ores of this district.
 The first mining in the Globe district | was done in 1876, and was for silver. | The Old Dominion, the principal pro duCer and typical mine of this field, | is opened on contact vein between a dio rite foot and hanging of carbonif erous limestone, over the greater part of which there is trachite eapping. Tle principal ore bodies are in the limestone and the ores are mostly OK hized ores, both above and below. The ores are highly silicious and require heavy fluxing with iron and lime. The lack of sulphide ores to furnish the iron needed in fuxing is one of the draw