The Arizona sentinel., 1903-04-15
LA FORTUNA MINE.

In the early days of gold discovery of Califor- nia lS4S when the news reached the gold miners of Sonora. there was a general exodus Of the dblc-bodicd 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 narallcl to the gulf following the mountain ridge known the Cflla range, just north or our present boundary. The road led to Yuma, and in passing the Gila range they went within few feet or yards of very modest outcrop or quartz which no one seemed to consider Of sui ficient value to merit any attention. That hum blc and insignificant quartz outcrop Is today the outcrop of the great Fortuna mine.
 It k 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 northweStcrly and reaches nearly to the Gila river at the point now known as BlaiSdcll 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 wcatherCd out at the surfaces, which, however. are much pittcd aS if by decompoSi- ton of some soft substance. But beyond these
 ow-lying hills of granite there are big outcropS of rock mich to the experienced eye indicate strntified formations. They are indeed strait fled. for the bulk of the range Southward and Southeastwari Is composed of regular Stratificd, laminated hard gneiSSic rock. use the word ''gnciSSic' in q very general and comprehensive Sensc. for you can describe these rocks with
 
 mira states and hornblendic Slates, 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, nl- though there are peculiariticS of color, and some yellow colorS which indicate to me the presence of some other mineral, possibly, tei- 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 1t now contains in he lower levels of the mine. The workings wh .ch have been carried on here have developed a condition of things which could not be foretold from an inspection of the outcrop. The vein or lode appears to be a chimney, not contino- ous ore body. nor q 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 remarkable first in this limited out crop; second in it's continuity in depth, It's con- tinued satisfactory rich eSs, and the promise 1 gives of enrichment by further veins dipping nto 1t on the footwall sides.
 Some facts in regard to the product or yield: The ore paid from the surface. The product or ore extracted up 10 the time has been about SC tons per day, which is sent to the 20-stamp mill each stamp of which crusheS about tons in every twenty-four hours. The extraction lS chiefly and largely by power drills. 4 force ! of 30 men is employed by this mine and mill 1 The greater part of the labor underground and mining is done by compressed air. The lode, was told, was to l5 feet wide. This large space permits the use or power drillS to grea' advantage. In the material hoiSted there are ! fragments of the wall rocks, some of which art thrown out, but many pieces pass through the mill. They would prefer to reject most Of this 1 wall rock. but 1t would take more time and cx penSe than it does 10 mill it, and there is chance Of some of it containing gold. From | these 80 tons of rock crushed daily the average | product is perhaps S4S,0O0 worth of gold pel
 month. Some months they have produced a, 1 high as S9O,OO1
 1 In the region of the Fortuna mine tho forma
 
 bornblende slate, with some 8rcnAceouS layer: Ike old micaccouS SandStoncS and quartziteS The mine k surrounded by black hornblendit
 and these SlateS are very evenly lam mated ridge after ridge.