The Arizona sentinel., 1901-12-04
LA FoRTrNA MINE.

In the early days of gold discovery Of Califor- mia, 1s4s, when tine news reached the gold miners Of Sonora, there was Q general exodus of the dnle-bodied men who were able to get away northwest to the new Fl Dorado iu California, and the state of Sonora contributed many men to the mining population. They took the old road which was known as the 'calnino real, " from EStancia and Altar northwest ward, nearly parallel 10 the gulf following the mountain ridge known as the GilG range just north Of our present boundary The road led to Yuma. and in passing the Gile range they went within a few feet or yards of very modest OuJcrOp of quartz which no one seemed to consider Of sui ficient value to merit any attention. That hum be 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 Giia range. This trends northwesterly and reaches nearly to the Gila river at the point now known as BlaiSdell 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 as if by decompoSi- tiol of some soft substance. But beyond these low-lying hills of granite there are big OutcropS of rock which to the experienced eye indicate Stratited formations. They are indeed strait fled, for the bulk Of the range southward and SoutheaStward is composed Of regular stratifcd, lalninated, hard gneissic rock. use the word ''gneissic'' in very general and comprehensive sense, for you cen describe these rocks with much more accuracy if you locGlize them as mica states and hornblendic states, with inter polations of quartzte 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 peculiariteS 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 HOlors. 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 he chimney. not continO- ouS ore body, nor a continuous vein with ore body or chimney or chute upon it. AS re marked the oCtcr3pp'ng points indicate that there is no very great longitudinal extension of this ore body
 The vein is remarka 3e first in this limited out crop; second in it's continuity in depth, its con- tinued satisfactory richness, and the promise it 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 &. tons per day. which is sent to the &)-Stalnp mill each stamp of which crushes about tons IT every twcnty-four hours. The extraction Is chiefly and largely by power drills. A force of SU men is employed by this mine and mill The greater part of the labor underground an6 mining is done by compressed air. The lode, was told. was to 15 feet wide. This largo space permits the use of power drills to grea advantage In the material hoisted there ar' fragments or the wall rOckS. some or WHICH ar thrown out, but many pieces pass throCgh tn' mill. They would prefer to reject most of thl wall rock. but it would take more time aud eX penSe than it 0oes to mill it. and there Is chance of some of it containing gold. Fron these 80 tons of rock crushed daily the aVerag product k perhaps S460OO worth Of gold De month. Some months they have produced a high as S90OD0
 In She region of the Fortuna mine the fOrma tionS appear to be wholly of mica slate an bornblende slate, with some arcnHceous layer Ike old micaceouS SanGSUones and quartZites The mine is surrounded by black hornblendi states and mica states, dipping SOuthw2rd an Southwestward at an angle of about 45 degree and these states gre very evenly lamiGatcC ridge after ridge.