The Arizona sentinel., 1902-09-17
LA FORTUNA MINE.

In the early days of gold discovery of CalifOr- mia. lS4S. 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 ''camino real '' 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 fcient value to merit any attention. That hum ble 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 it's 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- tion of some soft substance. But beyond these low-lying hills of granite there are big outcropS of rock which to the experienced eye indicate stratiied formations. They are indeed strait fled for the bulk of the range Southward and SoutheaStward is composed of regular Stratified. laminated. hard gneiSsic rock l 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 mica states and hornblendic states. with inter polatiOnS of quartZite beds, especially in the upper part of the series. with green stains, SUD- 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 colorS, which indicate to me the presence of some other mineral. possibly. tel lurium. which by it's decomposition has given these colorS. The fact remains, however, that the bullion from the upper part of the vein con talns more copper than it now contains in the lower levels Of the mine. The workings which ha-y been carried on here have developed . condition of things which could not be foretolt from an inspection of the outcrop. The veiT or lode appears to be chimney not continO ous ore body. nor continuous vein with an ort body or chimney or chute upon 1t. As re marked the outcropping points indicate tha there IS no very great longitudinal extension o this ore body.
 The vein is remarkable first in this limited out crop; second, in it's continuity in depth, it's con tlnued satisfactory richness. and the promise l gives of enrichment by further veins dippin; nto it on the foot-wall sides.
 Some facts in regard to the product or yield The ore paid from the surface. The product O. ore extracted up to the time has been about & tons per day, which is sent to the 20-stamp mill each stamp of which cruSheS about tons Il every twenty-four hours. The extraction l chiefly and largely by power drills A fore of 80 men is employed by this mine and mill The greater part of the labor underground an mining is done by compressed air. The lode, was told was 6 to 15 feet wide. This larg space permits the use of power drills to grea advantage. In the material hOiSted there ar fragments of the wall rocks, some of which ar thrown out, but many pieces pass through tn mill. They would prefer to reject most of thi wall rock. but it would take more time and eN penSe than it does to mill it.. and there is chance of some of it containing gold. FrOT these SO tons of rock crushed daily the aYcrag product iS perhaps S4S.000 worth of gold pc month. Some months they have produced a high as S900O0.
 In the region Of the Fortuna mine the formi tiOnS appear to be wholly of mica slate an hornblende slate, with some arenaceouS layer Ike old micaceOuS SandStOneS and quartZite: The mine is surrounded by black hornbendi states and mica states dipping SOuthward an SouthweStward at an angle of about 45 degree and these states are very evenly laminatet ridge after ridge.