The Arizona sentinel., 1901-09-25
LA FORTUNA MINE.

In the early days of gold discovery of Caliror- mia. lS4S. when the news reached tho gold miners of Sonora. there a general exodus of the able-bodied men who were able te get away northwest to tEc new Fl Dorado in California and the state of Sonora contributed many men 10 the mining population. They took the old road, which Was known as the ''camino real, '' from EStancia and Altar northweStward, nearly parallel to tho gulf, following the mountain ridge known as the Glla 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 nclent Vaine to merit any attention. That hum bic 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 Tn 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 if by decomposi- Sion of some soft substance. But beyond these Iow-lying hills of granite there are big outcrops of rock which to the experienced eye indicate Stratified formations They are indeed Strati- fled for the bulk of the range southward and SoutheaStward is composed of regular Stratified laminated hard gneiSSic rock. I 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 SlateS 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- 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 or 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 rcrnariab b!c rt in tbfs limited ont crop; second in it's continuity in depth. it's con- tinued satisfactory richness. and the promise il 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 or ore extracted up to the time has been about s( tons per day which is sent to the 20-Stampm1ll each stamp of which cruSheS about f tons iI every twenty-four hours. The extraction is chiefly and largely by power drills. 4 force of 80 mon is employed by this mine and mill The greater part of the labor undcrrround anC mining is done by compressed air. The lode was told, was 6 to 15 feet wide. This large space permits the use of power drills to great SuNanJdge III the HldIcflal nOlSJcC IneIc art fragments of the wall rocks, some of which arC thrown out but many pieces pass through thf mill. They would prefer to reject most of this wall rock but it would take more time and eX penSe than 1t does to mill 1t. and there is chance of some of 1t containing gold. From these 80 tons of rock crushed daily the averag, product is perhaps Sis000 worth of gold pc month. Some months they have produced a! high as Sq0.000.
 In the region of the Fortuna mine the forma tionS appear to be wholly of mica slate apC hornblende slate. with some arenaceouS layer Ike old micaceOuS SandStoneS and QuartZiteS The mine is surrounded by black hOrnblendi states and mica states, dipping Southward am SouthweStward at an angle of about 45 degrees and these states are very evenly laminated ridge after ridge.