The Arizona sentinel., 1902-09-24
LA FORTUNA MINE.

In the early days of gold discovery of Califor- mia, 1S4s, when the news reached the gold miners of Sonora, there was Q general exodus Of the able bodied men who were able to get away northwest to the new Fl Dorado in California. snd 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 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 very modest outcrop of quartz which no one seemed to consider of sui rcient value to merit any attention. That hum ble and insignificant quartz outcrop is today the outcrop of the great Fortuna mine.
 It is situated OF the westward slope and nearly ct the base of the range of mountains called on some of the old maps the Gila range. This trends northweSterly and reache; nearly 10 the Giia 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 deconpoSi- 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 stratihed formations. They are indeed strait fed 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 mica slates and hornblendic states with inter polations of QuGrtZite 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 colors, which indicate to me the presence of some other mineral, possibly, tel furium, which by it's decomposition has given these colors. The fact remains, however. that the bullion from the upper part of the vein con tainS more copper than 1t now contains in the lower levels of the mine. The workings which have been carried on here have developed a condition of things which could not he foreuold from inspection of the outcrop The vein or lode appears to be chimney not a contino GUS ore body, nor a continuous vein with an ore body chimney or chute upon it. As re- marked the outcropping points indicate that there is no very great longitudinal extension of this ore body.
 The vein is remarkable frstin this limited out crop; second in it's continuity in depth, it's con- tinued satisfactory richness, and the promise 1t gives of enrichment by further veins dipping -nto it on the foot-wall sides.
 Some facts in regard to the product or yield: The ore paid from the surface. The product or ore extracted up to the time has been about so tons per day, which is sent to the 20Stamp 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, told 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 mill. They would prefer to reject most of this wall rock. but it would take more time and ex pcnse than it does to mill it, and there is g chance of some of it containing gold. From these so tons of rock crushed daily the average product is perhaps S4S.000 worth Of gold pel month Some months they have produced a: high as S90.OO0.
 In the region of the Fortuna mine the forma lions appear to be wholly Of mica slate ana hornblende slate, with some arenaceous layer: Ike old mic8ccous SandStoneS and QuartZiteS The mine is surrounded by black hornblendit states and mica states, dipping southward ana Southwestward at an angle of about 45 degrees and these states are very evenly laminated ridge after ridge.