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Mexico Operations

A Look at Los Juarez

Conceptual drill hole design (for budget purpose) targeting contoured gold in soil within the NW trending jasperoid trend (4 holes with grey collar) and NE fault and gold in soil anomalism (4 holes with blue collar).

Fig. 1 shows the numerical 3D models generated from the Au soil geochemical data. The proposed planned drillholes (LJ_5 to LJ_10 blue collars) were positioned based on the high Au soil contoured values (yellow & orange) trending to the northwest and further holes planned corresponding to the NE trending fault and gold in soil anomaly (red, orange, yellow). Infill soil sampling down to 25m centres would tighten up the definition of this NE gold trend and provide better control in which to target these drill holes.


Figure 2 shows the numerical model generated from the Au rock chip geochemical data. The proposed planned drillholes (LJ_5 to LJ_10) were positioned based on the high Au rock chip values trending to the NE and NW, the NE trend corresponds to the NE trending fault interpreted and gold geochemical anomalism and the NW the jasperoid trend and associated mined surface pits. Note rock chip data only provides anomalism where surface observations warrant taking samples, it does not provide evenly spaced data like the soil survey which was taken on 100m centre grid.

Mexican Mining Operations

Although USAC has extensive antimony mineralization at Thompson Falls, Montana, the time and cost of re-permitting the mine as well as the uncertainty of even getting a permit caused USAC to return to Mexico to mine. Most of the Mexican antimony deposits are oxide ores or mixed oxide sulfide deposits. The oxides are recoverable by gravimetric methods, typically jigs and tables. The sulfide ores are recoverable by flotation. During World War II, the United States relied on Mexico for antimony for military applications. Historically, Mexico was at one point the second largest producer of antimony in the world. USAC does not claim any reserves by S.E.C. definitions.


At the Los Juarez property USAC relied on a Mexican Government publication, Consejo de Recursos Minerales, Monografia Geologico-Minera del Estado de Querearo, pages 74-75. The paper reported a reserve of 1,000,000 metric tons containing 253 grams per ton silver and 1.8% antimony 40 hectares (100 acres). The deposit was interpreted as a manto (layered) deposit up to 5 meters thick. Although USAC used the report to start mining, it was disallowed by the S.E.C. as a basis for reserves. Detailed mapping and sampling delineated jasperoid mineralization over an east-west strike length of 3.5 kilometers with a maximum width of 1 kilometer. Unlike most Mexican deposits, this deposit is primarily all sulfide. Preliminary exploration indicates that it could be a deep-seated jasperoid. USAC controls this property directly. The grade of 1,415 tons of rock from the Minas Grande area that was milled assayed 0.728% antimony, 6.22 ounces (193 grams) of silver per metric ton, and 0.023 ounces of gold (0.7 grams) per metric ton.


USAC is sourcing mill feed and DSO for Madero from the Soyatal District in the State of Queretaro, Mexico. The deposit was the third largest antimony producer in Mexico. Donald E. White (U. S. Geological Survey Bulletin 960-B, Antimony Deposits of Soyatal District, State of Queretaro, Mexico, 1948) prepared an extensive report and said that the production (p. 40) was estimated through 1943 at 25,630 metric tons of metal contained. USAC has purchased this property but claims no reserves.

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