The Arizona sentinel., 1900-10-31
LA FORTUNA MINE.

In the early days of gold discovery of Califor- mia. 1S3S, when the news reached the gold miners of Sonora. there was general exodus of the ablebodied 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 suf- 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 al 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 weathcred out at the surfaces, which, however, are much pitted as if by Gecomposi- 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 stratifed formations. They are indeed strait. fled, for the bulk of the range southward and Southeastw2rd is composed of regular stratffed, lanlinated, hard gneissic rock. I 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, 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 lurium, which by its decomposition has given these coiors. The fact remains, however, thai 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 6 condition Of things which could not be foretolG from an inspection of the outcrop. The veiI or lode appears to be a chimney, not a contino ous ore body, nor a continuous vein with an orc body or chimney or chute upon it. As re marked the outcropping points indicate thai there is no very great longitudinal extension o this orc 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 i giveS of enrichment by further veins dippin; into it on the foot-wan sides.
 Some facts in regard to the product or yield Tke orc paid from the surface. The product o ore extracted up to the time has been about & tons per day, which is sent to the 2O-stamp mill each stamp of which crusheS about tons il every twenty-four hours. The extraction i chiefly and largely by power drills. A fore of 30 men is employed by this mine and mill The greater. part of the labor underground ent mining is done by compressed air. The lode, was told, was to 15 feet wide. This larg space permits the use of power drills to grca advantage. h 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 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 averag product is perhaps s48,OoO worth of gold De month. Some months they have produced 8 high as s99,000.
 In the region of the Fortuna mine the lorna tions appear to be wholly Of mica slate an hornblende slate, with some arenaceous layer Ike old mfcaceous sa 1ds tones and quartzites The mine is surrounded by black hornblendi states and mica slates, dipping southward an southwestward at an angle of about 45 degrees and these slates are very evenly laminated rsige 7'ss. -5Irc This is apparently COT