The Arizona sentinel., 1903-04-01
LA FORTCNA MINE.

In the early days of gold discovery of Califor-
 niG, IS4s when the news reached the gold miners
 of Sonora, there was a general exodus of the
 Ahle-bodied men who were able to get away
 northwest to the Gcw Fl Dorado in California,
 and the state of Sonora contributed many men
 to the mining population. They took the old
 road. which known as the ''camino real,
 from EStancia and Altar northweStWard, 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 a
 few feet or yards of a very modest outcrop of
 quartz which no one seemed to consider of sui
 ticient value to merit any attention. That hum
 ble 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 Gila range. This
 trends nOrthwesterly and reaches nearly to the
 Gila river at the point now known as BlaiSdell. 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 weathered out at the surfaces which however, arc much pltted as If by decomposi- tion of some soft substance. But beyond these low-ying hills of granite there arc big OutcropS Of rock which to the experienced eye indicate
 stratifcd formations. They arc indeed strait fled, for the bulk of the range SOUthward and
 southeastward is composed of regular stratifed laminated. hard gneisSic rock. l use the word ''gneSSic' in a very general and comprehensive sense for you can describe these rocks with much more accuracy if you localiZe them as mica states and hOrnDlendic states, with inter polatiOnS of QuartZite beds, especially in the upper part of the series, with green stains sup posed to be stains Of copper ana decomposition Of copper ore, which they probably are, al though there are pec1lliaritieS of color, and some yellow colorS which indicate to me the 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 he ! lower levels O the mine The WOrkinUS r.. ph have been carried on here have developed a l condition of things which could not be foretold
 from an inspection of the outcrop. The vein 1 or lode appears to be a chimney, not cOntlno- l ouS ore body nor 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 l this ore body
 The vein is remarkable first in this limited out crop; second in it's continuity in depth it's con 1 tinued satisfactory rich eSS and the promise 1 1 gives Of enrichment by further veins dipping ] nto 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 so tons per day, which is sent to the 2OStamp mill, | each stamp of which cruSheS about tons in every twenty-four hours The extraction is chiefly and largely by power drills. A force | of so 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 of power drills to great advantage. In the material hoisted there are | fragments of the wall rocks, some of which are ! 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, and there is a ! chance of some of it containing gold. From l these 30 tons of rock crushed daily the average
 product is perhaps S4S000 worth of gold per
 month. Some months they have produced as
 high as S90000.
 in the region of the Fortuna mine the lorna 1 tionS appear to be wholly of mica slate and l hornblende slate with some arenaceouS layers ! Ike old micaceouS SandstOneS and quartZiteS. ! The mine is surrounded by black hOrnblendiC
 slateS and mica states dipping southward and l SouthwestTard at an angle of about f5 degrees,
 and these slates are very evenly laminated i ridge after ridge.