The Arizona sentinel., 1901-08-21
LA FORTUNA MINE.

In the early days of gold discovery of Califor- mia, 1S48, 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 the Gila range, just north of our present boundary. The road led to Yuma, and in passing the Gi-a range they went within few feet or yards Of very modest Outcrop of quartz which no enc seemed to consider of sui fcienJ 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 i at the base of the range of mountains called on ! some of the old maps the Gila range. This 1 trends northweSterly and reaches nearly to the Gila river at the point now known as Blaisdel. l 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 if by decompoSi- ton of some soft substance. But beyond these low-lying hills of granite there are big outcropS of rock which to the experienced eye indicate SCratified formations. They are indeed strait fled. for the bulk of the range southward and SoutheaStward is composed of regular Stratified laminated, 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 locaiiZc them as mica states and hornblendic SlateS, 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 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 Q condition of things which could not be foretold from an inspection of the outcrop. The vein or lode appears to be a chimney. not a contino- OuS ore body. nor a continuous vein with an ore body chimney chute upon it. As re- marked the outcTopping points indicate that there is no very great longitudinal extension of 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 ii 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 from the surface. The product Ol ore extracted up to the time has been about 8 tons per day, which is sent to the 20-stamp mill each stamp of which cruShes about tons II every twenty-four hours. The extraction Il 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 ant 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 grea advantage In the material hoiSted there ar fragments of the wsGi rocks, some of which ar thrown out. but many pieces pass through tn mill. They would prefer to reject most of tn wall rock but it wosfld take more time and e. penSe than it does to mill it. and there Is
 chance of some of it containing gold FroI these 80 tons of rock crushed daily the aVeTag product is perhaps S48,000 worth of gold DC
 month. Some months they have produced a high as Sa0.000.
 In the region of the Fortuna mine the form; tions appear to be wholly Of mica slate an
 hornblende slate, with some arenaceouS layer Ike old micaceouS SandStoneS and quarJZite
 The mine is surrounded by black hornble1d
 states and mica states dipping southward a1
 southweStwar6 at an angle of about 45 degree
 and these slates are very evenly laminate
 ridge after ridge.