The Arizona sentinel., 1902-04-02
LA FORTUNA MINE.

In the early days Of gold discovery of Califor- nia. lsIs when she news reached the gold miners of sonora. there was @ general exodus of the dole-bOdied men who were able to get away northwest to the new Fl Dorado in California and the state of Sonora contrib lted many men to tne mining population. They took the old road, which was known as the ''camino real, '' from Es5A lcia and Altar aorthweStward nearly parallel to tho .uf 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 u e. wen. within few feet or yards of very modest outcrop of quartz which no one seemed to consider Of sui 1icie1t value to merit any attention. That hum bic and insignificant quartz oIterop is today the outcrop of the great Fortuna. mine.
 It is situated on the wcstya -d slope and nearly a. the base Of tho range Of mountains called on some of the old maps the Ciiia rang. This trends northTeSserly and reaches neariy to the Gila river at tho point now known as 3lGisdc,l The railway ln l1S course to Yuma passes around the northwest poist of this range Where the rocks arc exposed ut that point they are mostly of homogeneous granite. Of gray color and weathered out at tha surf secs which how: yer, are much pit5ed as if 5v decoTnpoSi- ton of some sort SubStaloS. But beyond these lowlying hills of granite there ar" big ou;crops of rock which to the experienced eve indicate stratified formations. They are indeed strait lied. for the bulk of the range SouthWar and southeaStward is composed Of regular Stratiaed laminated. hard gneiSsic rock 1 use the word ''gneissic' il 2 very general and comprehensive sense. for you can describe thesa rocks with
 
 mica states and hornblCndic SfataS, with inter po.asions Of quartZitc 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 all though there arc peculiaritieS 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 coloFs.- The fact renlai9s however that the bullion from the upper part Of tho vein con- tains more copper than it now contains In the lower levels or the mine. The workings which have been carried on hero have developed condition Of things which could no: be foretold from an inspection of the outcrop. The vein or lode appears to be chimney. not a conJino- o1S ore body. nor continuous vein with an ore body or chimney or chute upon it. As re- marked the outcToppiDg points indicate that th:re Is no very great longitudinal extension of this ore body.
 The vein is remarkable first in this limited out crop; second, Tn 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 50 tons per day. which is sent to the 20-Staup mill each stamp of which cTlSheS 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 1He gIeaOer part CT the laoor unucrground and mining Is done by compressed air. The lode. I was told was to l5 feet wide. This large space permits the Use of power drills to great advantage. Tn the material hoiSsed there are Fragments Of the wall rocks. some of which are thrown cs1t. but many pieces pssss through the mill Thes' would prefer to reject most of this wall rock bIt it would take more time and ex- E~1lSe than It doe-S to mill Il. and thhre !S a chance of some Of it containing gold. From these SC tons of rock crushed G;:AY the average product iS perhaps TiS.010 worth of goid per month. Some months they have produced as high as S9G001
 In the region of the Fortuna mine the foyma- lions aPOnzfr to De wholly Of mica slate and hornblende slate with some arenaceouS layers Ike old micaceouS SandstoneS and quaTtziteS. The mine is surrounded by black hOrn0lendic states and mica states, dipping Southward and sOuthweStward at an angle of about 45 degrees and these states are very evenly lanrinated ridge after ridge