San Antonio Mine
 

Although the original staking of the property took place in 1991, production commenced only in 1932. Over the years, the capacity of the mill was increased from 150 to 550  tons/day.

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Mineralization in this deposit occurs in quartz veins within a diabase sill which intrudes a sequence of volcanic and sedimentary strata. The sill dips NE at 45 degrees and mining operations have followed it down to a vertical depth of 1640m by a succession of winzes interconnected by horizontal haulage ways.

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The productive veins are mainly restricted to a particularly thick part of the sill, and essentially confined to the sill itself. The mineralized veins form 3 groups or sets, oriented in three different attitudes, and developed in shear and fracture zones which cut the sill. In all, 132 separate veins were worked.

The quartz veins are mineralized with pyrire, minor chalcopyrite, sphalerite and galena, and contain ankerite and albite. Carbonate, albite and pyrite have developed in the wall rock as alteration products. Gold occurs mainly in the vein pyrite, but is also present locally as free gold. In 1961, a mass of native gold weighing 211 oz. was discovered. The gold:silver ratio in the mine averaged 6:1.

The mill was formerly famous for its high recovery - about 98%. Au from heads assaying about 0.288 oz./ton.

                                   Tons milled            - 4,474,9211

                                    Gold Recovered  - 1,199,878 oz.

                                    Silver Recovered - 192,205 oz.

                                     Average Grade     - 0.27 oz./ton

                                     Years Worked       - 1932-1985

 

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