Alamo Dorado yields highest grades yet

Stepout drilling at the Alamo Dorado project in Mexico’s Sonora state has intersected the highest silver grades yet for Corner Bay Minerals (BAY-T).

Hole 49, collared on line 3+50 South, returned 52.5 metres (from 220.5 to 273 meters) grading 697 grams silver and 0.41 gram gold per tonne. The interval is outside the known deposit and lines up nicely with the southern extension of the suggested starter pit, only slightly deeper. Moreover, no significant sulphide mineralization is present, with the gold and silver being disseminated throughout what appears to be oxidized rock similar to that hosting the deposit.

A second hole, No. 48, collared on the same section as hole 49, came up dry. However, Corner Bay believes it was drilled on the opposite side of a crosscutting fault. Also, three earlier and unsuccessful holes drilled south of hole 49 may have been cut short. All will be extended.

The latest holes are part of a 10,000-metre campaign aimed mainly at extending the deposit in several directions, as well as extending earlier holes that bottomed in high-grade silver and gold mineralization at the footwall contact of the epithermal system. The program is being funded with proceeds from a $1.2-million financing, completed in December 1999.

Corner Bay began the Alamo Dorado project in September 1997, after optioning 503 ha from local vendors for US$800,000, payable over six years. The company has since staked 4,865 ha of surrounding ground and drilled more than 42 holes in two campaigns.

Excluding the stepout hole, Alamo Dorado hosts 47.9 million tonnes of near-surface material that grades 52 grams silver and 0.2 gram gold. This is part of an overall resource of 74.8 million tonnes grading 41 grams silver and 0.16 gram gold.

Mineralization dips to the west, sub-parallel to the western slope of the ridge that encloses it, making low-cost open-pit mining a strong possibility. Initial estimates suggest stripping ratios as low as 0.4-to-1 (T.N.M., Nov. 29/99).

Both silver and gold occur predominantly as free particles disseminated in the host gneisses and schists. Silver is also tied up in secondary oxide minerals, particularly chlorargyrite, a soluble chloride mineral found in secondary enrichment zones above silver veins subjected to intense weathering. Metallurgical studies are continuing, with nine columns now under leach.