The Arizona sentinel., 1901-07-10
LA FORTUNA MINE.

In the early days of gold discovery cf Caiifor- nia. I84S, when the news reached the gold miners of Sonora there was 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 SGgora contributed many men to the mining population. They took the old road, which WAS known as the ''caulino real from ESJancia and Altar northWeStWard, nearly parallel to the gulf. following the mCunaain ridge known as the Gila range. just north of our present boundary. The road led to Yuma and in passing the Glla range they went within few feet or yards Of a very modest outcrop of quartz which nc one seemed to consider of suI- ficient value to merit any attention. That hum ble aud insignificant quartz outcrop is today the outCrep 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 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. 0ecOmpOSi- 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 Stratified formations. They are indeed strait fed, for the bulk of the range Southward and SoutheaStward is composed Of regular Stratifed lamlnated, hard gneiSsic rock. use the word "gneiSSic' in a very general and comprehensive sense, for you can describe these rocks with much more accuracy if you locaiiZe them as
 
 polations of quartZite beds, especially in the upper part of the series, with green stains sun- posed to be stains of copper and decomposition Of copper ore, which they probably are, al- though there are pocuiiaritieS of color and - some yellow colorS, which indicate to me fhp 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 ouJcrop. The vein or looe appears to be chimney, not q contino- ouS ore body. nor continuous Yein with an ore body or chimney or chute upon it. As re- marked the outcrepping points indicate that theFe IS no very great long1t Cdinal extension of this ore body.
 The vein is remarkable first in this limited out crop; second, m its continuity in depth, it's uon- -nnued satisfactory richness, and the promise il gives Of enrichment by further veins dipping into it on the fOot-wal sides.
 Some facts in regard tG the product or yield: The ore paid from the surface. The product or ore extracted mp to the time has been about 90 tons per day which is sent to the 2OStamp mill. each stamp Of which Crushes about tons in every twentyfour hours. The extraction is chiefly and largely by power drills. A force of SO men IS employed by this mine and mill. me greater part of the labor underground and mining IS done by compressed air. The lode, l was told, was 6 to l5 feet wide This large space permits the use of power drills to great advantage. In the material hoiSted there are fragments Of the wall rocks some of which arc thrown out, but many pieces pass through the mill They would prefer to reject most of this wall rock. but it would take more time and ex- pense than it does to mill it. ard there is a chance of some of it containing gold. From these 50 tons of rock crushed daily the average product is perhaps As.009 worth ef gold per month. Some months they have produced as high as StjO COG
 la the region of the Fortuna mine tho foTIna- tlons appear to be wholly Of mica slate and hornblende slate, with some a-enaceous layers Ike old micaceous SandStoneS and quartZiteS. The mine IS surrounded by black honblendic states and mica Slates, dipping Southward ard southwestward at an angle Of about 45 degrees and these states are very evenly laIninatcd ridge after ridge.