The Arizona sentinel., 1901-07-17
LA FORTUNA MINE.

Fn the early days of gold discovery of Califor- nia, ls4S, when the news reached the gold miners ot 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 lnen 10 the mining population They took the old road, which was known as the ''camino real, from EStancia und Altar northWeStward, nearly parallel to the gulf, following the mountain ridge known as the Gila range, inst north of our present boundary. The road led to Yuma. and in passing the Gila range they went within few feet or yards of @ very modest outcrop of quartz which no one seemed to consider of sui feient value to merit any attention. That hum ble and insignificant quartz outcrop is today the outcrop of the great Fortuna m1ne
 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- tloa of some soft substance. But beyond these lovlying hills of granite there are big outcrcps of rock which to the experienced eye indicate Strattfed formations. They are indeed strait Led, for the bulk of the range southward and southeastward is composed of regular Stratided laminated, hard gneiSsic rock. use the word 'gnelSslc" in very general and comprehensive sense, for you can describe these rocks with much more accuracy if you localiZe them as mica states and hornblendic states with inter polaSons of quartzite beds. especially in the upper part of the series with green stains sun posed to be stains of copper and Accommodation of copper ore, which they probably are ol though there are peculiaritieS of color and some yellow colors, 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 levels of the mine. The workings which have been carried on here have developed 2 condition of things which could not be foretold from an inspection of the outcrop. The vein CT lode appears to be chimney, not a contino- GUS ore body, nor continuous vein with an ore oooy or chimney or chute. upon it. As re- marked the outcropping points indicate that this ore body.
 Theveinis is remarkable first in this limited out. crop; second in its continuity in depth it's con Gnned satisfactory richness, and the promise ii FlFes or enrichment by further veins dipping into 1t on the foot-Wall sides
 Some facts in regard to the product or yield The ore paid from the surface. The product or ere extracted up to the time has been about S( tons per day, which is sent 10 the 20-stamp mill each stamp of which crushes about 4 tons ir every twentyfour 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, was told, was to 15 feet wide. This large space permits the use of power drills to great advantage. In the material hoiSted there art fragments of the wall rocks, some of which art thrown out, but many pieces pass through tho mill. They would prefer to reject most of thi: wall rock. but it would take more time and ex PenSe than 1t does t1 mill it, azid there is { chance of some Of it containing gold Prom these 30 tons of rock crushed daily the ayerag, product is perhaps S4S GOO worth of gold pe' month Some months they have produced a, high as $o0.0O0
 In the region of the Fortuna mine the forma tionS appear to he wholly of mica slasc anC hornbiende slate, with some arcnaceous layer Ike old micaceOus SandstOnes aud 0uarfzitpS The miRf is sGrpaunded by black hornhlcndi states and mica. states, dipping southward ant SouthweStTaFo at en angle Of about b degrees and these states are very evenly laInirated ridge after ridge.