The Arizona sentinel., 1900-12-05
LA FORTUNA MINE.

In the carly days Of gold discovery Of CaiifcT mia, IS4S, when the news reached the gold miners Of Sonora, there was a general exodus of the able-bodied men who were able to get away northwest to the new Fl Dorado in California, and the state of Sonora contributed many men to the mining population. They took the old road, which was known as the "cGmino real g from Estancia and Altar northweStward, nearly parallel to the gulf, following the mountain ridge known as the Gila range, just north of our present boundary. The road led to Yuma and in passing the Gila range they went within a few feet or yards of a very modest outcrop of quartz which no one seemed to consider of sui hcient value to merit any attention. That hum 1Ie and insignificant quartz outcrop is today the outcrop of the great Fortuna mine.
 It is situated on the westward slope and nearly at the base of the range of mountains called on some Of the old maps the Gila range This trends northwesterly and reaches nearly to the Gila river at the point now known as Blaisdell The railway in its course to Yuma passes around the northwest point of this range. Where the rocks are exposed at that point they are mostly of homogeneous granite, of gray color and weathered out at the surfaces, which, however. are much pitted as if by decomposi- NiOA Ol SOI1C oOll SuOSIduC6 put DCyOEQ these low-lying hills of granite there are big outcrops of rock which to the experienced eye indicate Stratifed formations. They are indeed strait fled. for the bulk of the range southward and southeastward is composed of regular stratified. laminated, hard gneissic rock use the word ''gneissic" in a very general and comprehensive sense for you can describe these rocks with much more accuracy if you localize them as ulo polations of quartzte beds especially in the upper part of the series, with green stains sup posed to be stains of copper and decomposition of copper ore, which they probably are, al- though there are peculiarities of color, and some yellow coloTs, which indicate to me the presence of some other mineral, possibly, tel lurium, which by its decomposition has given these colors. The fact remains. however, that the bullion from the upper part Of the vein con- tains more copper than it now contains in the lower le7'els of the mine. The workings which have been carried on here have developed a condition of things which could not be foretold from an inspection of the outcrop. The vein or lode appears to be chimney not a contino- ous ore body, nor continuous vein with an ore body or chimney or chute upon it. As re- marked the outcrOpping points indicate that sHCIC lo nO fCtg SISdS 4ulelLOul-4dl eAIcnStOn or this ore body.
 The vein is remarkable first in this limited out crop; second, in its continuity in depth its con- tinued satisfactory richness and the promise it gives of enrichment by further veins dipping into it on the foot-wall sides.
 Some facts in regard to the product or yield: The ore paid rom the surface. The product or ore extracted up to the time has been about SO tons per day, which is sent to the 2O-Stamp mill each stamp of which crusheS about tons in every twenty-four hours The extraction is chiefly and largely by power drills A force of 80 men is employed by this mine and mill The greater part of the labor underground and mining is done by compressed air. The lode, I was told, was to 15 feet wide. This large space permits the use of power drills to great advantage. In the material hoisted there are fragments of the wall. rocks, some of which are thrown out but many pieces pass through the mul. They would prefer to reject most of this wall rock but it would take more time and ex- pense than it does to mill it. and there is chance of some of it containing gold From these so tons of rock crushed daily the average product is perhaps s4S.OOO worth of gold per month. Some months they have produced as high as s9O020,
 In the region of the Fortuna mine the forma- tionS appear to be wholly of mica slate and hornblende slate, with some arenaceous layers Ike old micaceouS Sandstones and quartzitcS. The mine is surrounded by black hornblcndic states and mica states, dipping southward and southwestward at an angle of about 45 degrees, and these slateS are very evenly laminated, ridge after ridge. This is apparently a con