The Arizona sentinel., 1901-08-14
IA T0RTUNA MINE


 Tn the early days of gold discovery of Calitor mia, lS4s, when the news reached the gold miners of Sonora, there was general exodus of the aole-oodieo men who were able to get away northwest to the new El Dorado in California and the state of Sonora contributed rany mon 10 the mining population. They took the old road, which was known as the "camino real, ." from Estancia and Altar northwestsyard nearly parallel to the gulf, following the mountain ridge known as the Gila range, justnorth of our present boundary. The road jed to Yuma and in passing the Gila range they went within a te| Feet or yards Of very modest outcrop Of Cu rtZ which no one seemed to consider of sui 1clent value to merit any attention. That hum DIG ana lnsignlhcant quartz outcrop is today the outcrop of the great Fortuna mine
 It is situated on the westward slope and nearly 8t 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 Cila 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 weatbered ont at the surfaces which however, are much pitted as If by decomposI- ron of some soft substance But beyond these low-lying hills of granite there are bic outcrons of rock which to the experienced eye indicate stratlned formations. They are indeed strait @ neu, TOT the o9lk of the range southward and SoutheaStward is composed Of regular stratiAed isminated, hard gneiSSic rock. use the word gnelSSlc m very general and comprehenSive sense, Tor you can describe. these rocks with mnch more accuracy if you localize them as mica slates and hornblendic states with inter poiatlonS Of quartZlte beds. especially in thc upper part Of the series, with green stains, sup posed to oe stains of copper and Accommodation or copper ore, which they probably are al though there are peculiarities of color and some yellow colors, which indicate to me the presence or some other mineral. possibly tel lurium- which by its decomposition has given these colorS. The fact remains however that me bullion from the upper part of the vein con talnS more copper than 1t 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 forctold from an inspection Of the outc-op The vein or lode appears to be d ehimney not q contino- ous ore body. nor continuous vein with an ore booy or chimney or chute upon it. AS re- marked the oItC-opping points indicate that th,'re IS no very great longitudinal extension of this ore body. VI
 The vein is remarkable first in this limited out, crop: second. in its continuity in depth it's con iInued satisfactory richness, and the promise it ElVeS or enrichment by further veins dinpinr into 1t 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 SQ tons per day. which is sent to the aO-starnp mill each stamp or which crushes about tons in . every Gwenty-four hours. The extraction is emery and largely by power drills 4 force Of 80 men is employed by this mine and mill. The greater part of the labor n lergrOund and mining Is done by compressed air. The lode 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 arc fragments of the wall rocks, some of which arc thrown out but many pieces pass through the mlll- They would prefer to reject most of this wall rock but it would take more time and OK pense than IL does to mill it. and there is a chance Of some of it containing gold. From these 30 tons of rock crushed daily the avera0o product lS perhaps $8.OOO worth of gold per month Some months they have produced as high as $90,O00.
 In the region of the Fortuna mine the forna. uons appear to be wholly Of mica slate and hornbende slate, with some arenaceouS larcrs Ike old micaceouS santlstones and quartzi;es The mine is surrounded by black hOrnblcndiC states and mica states, dipping southward anc SouthweStward at an angle of about 45 degrees and these states are very evenly laminated ridge after ridge.