The border vidette., 1903-06-20
ARIZONA COPPER FIELDS.
Now Produce One-FOurth of the
 Worlds Copper.

he says is now the third district of the
 United States and fourth in the world in the matter of copper production.
 No other field has, he says, shown such marked gains in production dur = ing the past decade and there is every reason to believe that the output will continue to increase for many years to come In reference to the several dis
 tricts the following is from the Copper Handbook:
 The copper zone of Arizona, broadly speaking, has a general southeasterly and northwesterly trend, and the cop per deposits, as a rule, are found along the contacts of igneous rocks, such as porphry and diorite, with limestone of the PaleoZic group, mostly of the carboniferous, series. The general geological 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. The counties are of princely size, and as the topography ranges from hilly to mountainous in most parts, not even the best known dis tricts have been developed yet. or even fully prospected. Nearly all of the ores of copper are found in Ari- zona, and native copper is of not un- common occurrence, especially in the mines at Clifton and Bisbee
 The Bisbee district, of which the town of that name is the center, is really part, geographically, of the great Sonoran copper belt of Mexico The ore deposits occur in carbonifer- ous limestones, bedded in nearly hori- zontal planes, and underlaid by quartz ite The veins are notable tor the quantity of fuccan along the walls, and are easily mined as a rule. The clay carries considerable finely con- minuted native copper and masses of native metal of respectable size are occasionally encountered The oxi- idized zone is notable for the richness and extent of its high-grade carbonate oreS
 The country rock of the Jerome dis trict is slate, extensively intruded by dioritjc igneous rocks, states and dior ties having a capping of unconformable limestones of later age and devoId of copper. There Is limited zone of oxidized ores, but the principal de pendence is rlaced upon the unaltered disseminated sul9hides. These are by no means remarkable for their high percentages of copper, but are notable for their great extent and the high values carried in gold ard silver
 The Clifton district has quartzite and limestone superimposed on granite, with intrusive eigneous rock of both basic and acid types, the entire forma- tion being greatly faulted. Ore occurs in both the eruptive rocks and the limestobes.
 Speaking more particularly of the Copper Queen mines at Bisbee, Mir Stevens says:
 The formation of the Copper Queen, and of the other mines in the Bisbee district, consists essentially of two limestone beds, the upper white and the lower blue, of Carboniferous age and dipping to the southward, these fanking a granite core. The Saost i'm i portant finds of ore have been at the i base of the upper limestone, winch is broken and interrupted by feldspathic igneous rocks, the latter evidently hay | ing a considerable bearing on the ore bodies, which are lenses, very cratic | in habits, the existence of which can : not be forecast with any degree of certainty. Developments of the past ! year or two have shown that the | formation carries extensive ore values | much deeper than was formerly sup ] posed. There are some very interest ing caves in the limestone, of practical | interest because good ore bodies always | have been found beneath them The i alteration zone is variable, running to i 200 feet in places, though rich oxi- dized ores have been found in the very lowest workings Azurite and mala- chite are found in considera ble quanti- ties, also a lesser amount of cuprite and some native copper, the latter all most invariably associated with the cuprite. The largest masses of native meta ranging up to several hundred weight in size, have not been found near the surface. as would be antici- pated, but at considerable depth,
 The company's new smelter at Dou glas, twenty-five miles southeast of Bisbee and very near the Mexican border, is approaching completion This will have a daily capacity of l,500 tons as against 1000 tons at the old shelter, and is assured an ample water supply. The new shelter will be fitted with every appliance for tabor saving and economical work