The Arizona sentinel., 1901-01-16
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 sble-bodied men who were able to get away northwest to the 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 tho ''camino real. " from Estancia and Altar northTestTard, nearly parallel to the gulf, following the mountain ridge known as the Gila range, just north of our present boundary. The road led to Yuma, and in passing the Gila range they went within q few feet or yards of a very modest outcrop Of quartz which no one seemed to consider of suf- 1cient value to merit any attention. That hum ble and insignificant quartz outcrop is today the outcrop of the great Fortuna mine.
 IL Is situated on the westward slope and nearly a. the base Of the range Of mountains called on some of the ed maps the Gila range. This trends northweStcrly and reaches nearly to the Gila river al the point now known as BlaiSdcil 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 weathercd out at the surfaces, which. however, are much pitted as if by decompoSi- tion of some soft substance. But beyond these low-lyiug hills of granite there are big outcrcps of rock which to the experienced eye indicate stratified formations. They are indeed strait fled for the bulk of the range southward and sou. .heaStward is composed Of regular Stratified, laminated. hard gleissic rock. 1 use the word ''gncissic' in d very general and comprehensive sense, for you can describe these rocks with much more accuracy if you localize them as mica states and hornblendic states, with inter- pOations of quGrtZte 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, al though there are peculiaritieS of color. and some yellow colors, which indicate to me the presence Of some other mineral possibly, tel luriu1n. 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 a condition of things which could not be foretold from an inspection Of the Outcrop The vein CT lode appears to be a chimney, not q 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 k no very great longitudinal extension o1 this orc body.
 The vein k remarkable first in this limited out crop; second in it's continuity in depth. it's cor tinaed satisfactory richness. and the promise il Civns of enrichment by further veins dipping into ii on the Toot-wan sides.
 Some facts in regard to the product or yield The ore paid from the surface. The product ol f-e aytr:letod nm fO the time has been abOut Si tons per day. which is sent to the 2O-stamp mill rch stamp of which brushes about tons il every twenty-four hours. The extraction l, chiefly and larg l. by power drills. 4 force of 80 men is employed by this mine and mill The greater part of the labor underground anC mining is doLe by compressed air. The lode, was told. was to l5 feet wide. This larg space permits the use of power drills to grea advantage. In the material hoiSted there arr fragments of the wall rocks some of which ar thrown out, but many pieces pass through tn mill. They would prefer to reject most of Uni wall rock. but it would take more time and eX penS" than it does to mill it, and there is chance of some of it containing gold. Fron these S9 tons of rock crushed daily the ave-ag product is perhaps S4800O worth of gold pc month. Some months they have produced a high as 59O.CC0.
 In the region of the Fortuna mine the forma tions appear to be wholly of mica slate an ho-nolcndc slate. with some areaaceOus layer Ike old m bceDuS SGnlStones and quartzites The mine i, surrounded by black horlblendi states ana mica states. dipping Southward an southwcstwa-d at an angle of about 45 degrees and these states are very ev' niy laminateC riaga .-to- ,ilgc mi a1p2~cn'lT cC1